Car running poorly

[Helirich]

Ok, I'm looking for freash ideas. First, let's talk about parts.

New fuel pump and filter (tank and lines cleaned out)
New fuel lines (every line under the hood replaced with braided stainless)
New coil, plugs, wires, cap and rotor (timing is bang on)
New air cleaner
New battery

All injectors spray (but I haven't done a balance test)
I rebuilt the warmup regulator (don't assume I did it right)

I previously had issue with power to the fuel pump. Ran a new power line. Today I ran a new ground line. Some people have suggested a plugged cat/muffler. I have confirmed the cat is clear and the muffler has been replaced with a short pipe.

Symptoms

Today I took it for a ride. Since I have been having trouble after warmup, I decided to unplug the WUR. Started right up. A little hunting for idle. (Not bad) I drove it around my yard for five minutes. It ran fine, even great. My yard is only 700 ft, so I can only get to second gear.

Pulled out on the road. Drove about 2 miles to get to a good road. Drove fine, even great. Out on the paved road, Went through the gears to fifth gear and 65mph. Drove fine, even great. There was some cracking up when revs got above 5,000, but I assume you don't go there much. Cruised at 65 for about three miles and it started running rough.

Turned around and cruised back to the dirt road in forth gear at 2500 rpm. Gradually it is losing power and missing. I went down the dirt road for about a mile and stopped and removed the gas cap. (Maybe drawing a vacuum?) Back in, no change. Stopped again and plugged in the WUR. Back in, no change. At this point, can't get out of second gear because of power.

Get back to the house and check water temp (both gauge and handheld lazor temp show about 150 degrees.) It idles perfect with no hunting. I shut it off and dump five gallons in because it's down to quarter tank. Start it back up and drive it around the yard and it drives fine, even great. So the short time it took to dump some more fuel in cooled something down that it runs great? The water temp is still the same. I don't have that much hair to pull out.

Ideas?

I'm leaning towards the WUP not working right. The problem with that is why does it run good for a while? Doesn't seem like it could cool down on the hot valve cover in five minutes. This was the longest drive I've made so far. Is that because I unplugged the WUR? Do you suppose I should try to insulate the WUR? If I insulate it, I'm defeating the purpose of having it.

[Bitsyncmaster]

When you unplug the WUR connector it takes a long time for it to go into normal mode. When cold your mixture is very rich.

So it looks like your engine is running better with the rich mixture caused by the cold WUR.

Sounds like your mixture is adjusted to lean. You can not adjust the mixture by tweaking it for best idle. That sets it wrong. You have to adjust the dwell of the working frequency valve to the book values if you want good performance cold to hot.

[Ron]

+1, Dave

After that trip, I would think the engine should be up to temp and suspect that the thermostat is stuck open or missing. Even so, it would have been warm enough that the WUR/CPR should have been maxed out and make it run rich and probably not idle. BUT, when you plugged it back in and ran it a short while, it should of cleared up.
I would check the thermostat and the WUR/CPR pressures as it warmed up after sitting all night, as discussed in the other thread. Then the CO last.

[Helirich]

When you unplug the WUR connector it takes a long time for it to go into normal mode. When cold your mixture is very rich.

So it looks like your engine is running better with the rich mixture caused by the cold WUR.

Sounds like your mixture is adjusted to lean. You can not adjust the mixture by tweaking it for best idle. That sets it wrong. You have to adjust the dwell of the working frequency valve to the book values if you want good performance cold to hot.

That's kind of what I'm thinking. I may unbolt the WUR and wrap it in a ball of bubble wrap. If the car will drive good for a long time, I think that would confirm it as the source. So far everytime I got the car to drive further, it was electrical. On today's drive I did two things. New ground on the fuel pump and unplug the WUR. I really should only do one thing at a time.

Even if the WUR is the problem, it could be that it is raising the control pressure too high.


+1, Dave

After that trip, I would think the engine should be up to temp and suspect that the thermostat is stuck open or missing. Even so, it would have been warm enough that the WUR/CPR should have been maxed out and make it run rich and probably not idle. BUT, when you plugged it back in and ran it a short while, it should of cleared up.
I would check the thermostat and the WUR/CPR pressures as it warmed up after sitting all night, as discussed in the other thread. Then the CO last.

I think the WUR got warmth through the valve cover. So when I plugged it in, it was allready hot and nothing changed. The WUR gets hot and leans the engine. (I knew that's what you meant) That's why Dave is saying it is allready lean and gets leaner after warmup.

I also thought the car should be warmer than that after that drive. Im not complaining about it though. (I live in FL)

At this point, I don't trust my fuel pressure gauge. (China junk) So for the time being ill plod along without it.


On a good note, I'm not disappointed in the power of the PRV when it's running good. Also, I had my first puplic encounter with a guy that flagged me down and asked if that was the BTTF car. Lol.

[Michael]

Until you can verify your mixture is properly set, you should not do anything else. You may just be wasting time and money. You should know that a dwell meter or at least a multi meter with dwell function is a very very wise investment.

[David T]

To properly adjust the mixture you must make sure everything else is perfect. The injectors must all have good patterns and spray evenly, the combustion chamber pressures should all be high and close, the valves all adjusted etc. All of the vacuum and advance systems, cold start, and warm-up systems working correctly. The throttle plates set, the idle system working, basically everything working as it should BEFORE you even think about touching that screw. No vacuum leaks too. That adjustment is so twitchy just a minor tweak has a big effect. Til you KNOW everything is perfect, it is probably best not to touch it. I would start by looking at all of the auxiliary systems that are affected by heat like the CPR and the vacuum advance. 1 leaky hose or one that fell off or isn't hooked up right can certainly kill performance. Even stale gas will have a noticeable effect. Another thing to look at is the electrical system If the voltage starts to drop the car will run badly. Verify the alternator is OK and the battery is good and all of the "big" connections are clean and shiny.

[FABombjoy]

You can adjust the WUR and CO by feel, by sensor, or by dyno (I've done all 3), but it really won't run optimally until the WUR is adjusted per workshop spec. Then adjust the CO. You can set CO by tweaking control pressure but transient fueling will be all goofy.

Insulating the WUR won't do anything from a diagnostic perspective.

How did you rebuild the WUR exactly?

[Helirich]

You can adjust the WUR and CO by feel, by sensor, or by dyno (I've done all 3), but it really won't run optimally until the WUR is adjusted per workshop spec. Then adjust the CO. You can set CO by tweaking control pressure but transient fueling will be all goofy.

Insulating the WUR won't do anything from a diagnostic perspective.

How did you rebuild the WUR exactly?

If I insulate the unplugged WUR and it drives good and then plug it in and it drives bad, I would say that narrows it down to a couple things.

I just bought a rebuild kit. The instructions were in German, but it's pretty straight forward. The big issue is no way to test it after I was done.

To all, I've adjusted points with a dwell meter, never fuel mixture. I guess I need to do some reading. It would seem to me that if the car runs good sometimes, it can't be far off.

[FABombjoy]

There is a pressure chart in the service manual. With a functioning gauge set you can verify/set WUR warm pressure via the hex screw under the cap on the bottom. Disable the vac enrichment system as indicated, and ensure the screw turns freely and isn't binding on the diaphragm. If it's all new parts this should be OK.

Cold will be harder to verify, but provided that you didn't alter the topside adjustment will hopefully be OK. This might be harder to perform in Florida and you want to stick the WUR in the freezer overnight once you're ready to test & adjust. I set the bottom end range on mine years ago on a February Michigan day.

[Michael]

....firm grasp on the obvious book

Problem is if I understand right, he has already done the basics and he had already messed with the mixture screw and tried to set it at idle. I could have read an old post wrong but if he has already cranked on it, he needs to get it at least close before buying any more parts so he can get a handle on what the car is doing with a close mixture instead of one that may be miles off.

[FABombjoy]

It bears repeating that the manual references utilization of a dwell meter as they were standard garage kit in 1981. Really you're measuring the duty cycle of the "frequency valve", which is a single Bosch electronic fuel injector, by setting a dwell meter in such a way as to provide 90 degrees of total resolution. You can use a modern meter that measures duty cycle and rescale the given values from 0-100. There are a bunch of DMMs that have a duty cycle function on Amazon for example.

[FABombjoy]

close mixture instead of one that may be miles off.
And with a functioning lambda system, you can set things in such a way to be miles off some of the time, and perfectly functional some of the time. Like a, "oh it runs great, just gotta let it warm up for 5 minutes then its golden" type of situation. I'm not a fan of K-jet but once in spec the car should drive reasonably well regardless of temperature & engine load.

[Ron]

I think the WUR got warmth through the valve cover. So when I plugged it in, it was allready hot and nothing changed. The WUR gets hot and leans the engine. (I knew that's what you meant) That's why Dave is saying it is allready lean and gets leaner after warmup.

I also thought the car should be warmer than that after that drive. Im not complaining about it though. (I live in FL)

At this point, I don't trust my fuel pressure gauge. (China junk) So for the time being ill plod along without it.


On a good note, I'm not disappointed in the power of the PRV when it's running good. Also, I had my first puplic encounter with a guy that flagged me down and asked if that was the BTTF car. Lol.
Yes, sorry, I meant "lean".

105 is too cold. 180 will keep the oil between 230 and 250 ( above boiling out moisture - below breakdown temps). But they up the thermostat to 190 to make the O2 sensor warm up faster. (This might be contributing to why it ran the way it did for that long.)

I agree that you are wasting your time until you set the pressures with a gauge you trust (starting with the PP...which affects the CP).

[Helirich]

There is a pressure chart in the service manual. With a functioning gauge set you can verify/set WUR warm pressure via the hex screw under the cap on the bottom. Disable the vac enrichment system as indicated, and ensure the screw turns freely and isn't binding on the diaphragm. If it's all new parts this should be OK.

Cold will be harder to verify, but provided that you didn't alter the topside adjustment will hopefully be OK. This might be harder to perform in Florida and you want to stick the WUR in the freezer overnight once you're ready to test & adjust. I set the bottom end range on mine years ago on a February Michigan day.

I did drill the hole to make the hex screw access. Right now I have the screw turned the whole way rich. (Or least pressure)


Problem is if I understand right, he has already done the basics and he had already messed with the mixture screw and tried to set it at idle. I could have read an old post wrong but if he has already cranked on it, he needs to get it at least close before buying any more parts so he can get a handle on what the car is doing with a close mixture instead of one that may be miles off.

Yes, I allready messed with the mixture awhile ago. That might not have been wise, but it is how I got it to run in the fist place. I'm not worried about buying parts, but I really don't have much to buy anymore. (Maybe a WUR) If it runs great for five minutes, I don't see needing injectors? If it runs great for five minutes, don't see needing a new fuel distributor. I don't think I needed to buy the coil, plugs, wires or cap & rotor, but I really don't mind having functional spares.


It bears repeating that the manual references utilization of a dwell meter as they were standard garage kit in 1981. Really you're measuring the duty cycle of the "frequency valve", which is a single Bosch electronic fuel injector, by setting a dwell meter in such a way as to provide 90 degrees of total resolution. You can use a modern meter that measures duty cycle and rescale the given values from 0-100. There are a bunch of DMMs that have a duty cycle function on Amazon for example.

I have an old dwell meter that I got as a preasent from my dad in the 80's. Lol.


Yes, sorry, I meant "lean".

105 is too cold. 180 will keep the oil between 230 and 250 ( above boiling out moisture - below breakdown temps). But they up the thermostat to 190 to make the O2 sensor warm up faster. (This might be contributing to why it ran the way it did for that long.)

I agree that you are wasting your time until you set the pressures with a gauge you trust (starting with the PP...which affects the CP).

Did I say 105? It was 150, but still cold for that long of a drive.

I have checked the PP with a differnt guage (from my Bronco) it was about right. (74 psi) I will have to rig something to use that guage to check CP. It's not the guage itself that's bad, but there are "quick disconnects" on it that leak or don't allow pressure through. Maybe I can replace them.

[Ron]

lol...got me again. I must be dyslexic.

FWIW, I wouldn't dismiss the coil because it ran fine a little while. I've seen coils cause similar problems. They can pass all of the measurement checks when cold, but it's common for them to break down after warming up. If you haven't tried another, check when hot. If you can shake it and hear its oil sloshing, replace it.



...
Today I took it for a ride. Since I have been having trouble after warmup, I decided to unplug the WUR. Started right up. A little hunting for idle. (Not bad) I drove it around my yard for five minutes. It ran fine, even great.
Was the engine cold at the time or warm and you unplugged it anticipating...

[FABombjoy]

I did drill the hole to make the hex screw access. Right now I have the screw turned the whole way rich. (Or least pressure)
This is the problem, full stop, end of line, case closed, no further troubleshooting required.
Set it up correctly per the manual pressure/temp chart. Plug the hole when done or your cold vacuum enrichment will not work. Then set CO.
Today's office visit copay is $20

[Helirich]

lol...got me again. I must be dyslexic.

FWIW, I wouldn't dismiss the coil because it ran fine a little while. I've seen coils cause similar problems. They can pass all of the measurement checks when cold, but it's common for them to break down after warming up. If you haven't tried another, check when hot. If you can shake it and hear its oil sloshing, replace it.

Was the engine cold at the time or warm and you unplugged it anticipating...

New coil, no change.

Engine was dead cold when I unplugged the WUR.


This is the problem, full stop, end of line, case closed, no further troubleshooting required.
Set it up correctly per the manual pressure/temp chart. Plug the hole when done or your cold vacuum enrichment will not work. Then set CO.
Today's office visit copay is $20

If it is leaning the engine out and I can't adjust the CP down, how can I set it up per the chart? I do have a plug in the access hole.

[Michael]

Just so you know, my car ran great with a bad fuel distributor for years. It was always a little finicky on starting. Sometimes it would start up perfectly, other times not and it didn't matter if the engine was hot/cold/warm, it could and did happen. It would also take a minute to warm up before I had good throttle response. I dismissed the FD for the same reasons as you but focused on the WUR since my car was getting to the point of starting cold, then immediately dying and taking time to get my accepted throttle response. When the car got to where it took 5 or 6 cold starts to stay lit, I ordered a new WUR, it was suggested I do a FD at the same time, so I bit the $600.00 bullet and did just that.

When I got my parts in, I did the wur first since it was quick and easy with no real improvement. I then did the FD, and had to adjust my mixture almost a full turn to make it start, then I fine tuned it once in closed loop. My car has been 100% perfect since and the only thing that upsets me is I waited so long to fix it.

I don't really know if there is any way to test a FD on a car. I know you can test the pressures into the FD and at the PPR, but any further than that would be well beyond my level of knowledge so someone else will have to walk you through that. I admit I rolled the dice on the FD, but I had checked almost everything else including new ignition components, fuel lines, O2 sensor, new injectors, etc. but it was the FD that made my car 100% again.

[Helirich]

Just so you know, my car ran great with a bad fuel distributor for years. It was always a little finicky on starting. Sometimes it would start up perfectly, other times not and it didn't matter if the engine was hot/cold/warm, it could and did happen. It would also take a minute to warm up before I had good throttle response. I dismissed the FD for the same reasons as you but focused on the WUR since my car was getting to the point of starting cold, then immediately dying and taking time to get my accepted throttle response. When the car got to where it took 5 or 6 cold starts to stay lit, I ordered a new WUR, it was suggested I do a FD at the same time, so I bit the $600.00 bullet and did just that.

When I got my parts in, I did the wur first since it was quick and easy with no real improvement. I then did the FD, and had to adjust my mixture almost a full turn to make it start, then I fine tuned it once in closed loop. My car has been 100% perfect since and the only thing that upsets me is I waited so long to fix it.

I don't really know if there is any way to test a FD on a car. I know you can test the pressures into the FD and at the PPR, but any further than that would be well beyond my level of knowledge so someone else will have to walk you through that. I admit I rolled the dice on the FD, but I had checked almost everything else including new ignition components, fuel lines, O2 sensor, new injectors, etc. but it was the FD that made my car 100% again.

Interesting. I wonder if you could have found anything by doing a balanced spray test. I have tested each injector separately by pushing the plate and spaying in a bottle. They appear to spray about the same, but of course, I don't know. I really need to set up six bottles at once and check.

My problem is even though I'm retired, I have 4-5 projects going at the same time. When I was looking at buying one several years ago, I decided not to because of too many projects. (And cars) The only reason I bought this at this time is it was local and a great price. I said when I bought it, I'm going to through a week at it. If it isn't driving after that, I'm going to park it till I finish some other stuff. Of course it is calling me everytime I walk in the garage. I can't devote all my time to this. If I knew I would get it going in two days, I would.

Also, even though I say I'm retired, I still teach people to fly helicopters for fun. I'm also a landlord for no fun.

[Ron]

After rereading the thread, I now remember that I was thinking rich, fouling the plugs out etc. And that plugging the WUR back in could straighten the A/F out and let it clear up. Which makes no sense either way because as we all agreed, the WUR would have been maxed out. I blame Michael and ?bad? drugs for this.

Anyway, since we have a cold engine starting right up, idling fine (assuming "not much hunting" is common/insignificant), reaching 104F where the WUR reaches its leanest, then continues to run fine including 65 MPH cruising, all over 10+ minutes before acting up, I could see the WUR performing well enough to suspect something else...Especially if it would idle OK all during this time (not mention). The pump could be failing, getting too hot...cooled off with fresh fuel; trash packing up somewhere in the fuel system...released when shutting it down; ignition pick-up coil getting hot..., etc.

Same conclusion though...go fishing until you replace the gauge set.

P.S. I don't see injector balance causing the symptoms. I would guess Michael's FD probably had trash in it since the symptoms were intermittent. (I wouldn't go there without, you guessed it..., checking the pressures when the problem is present.)

[FABombjoy]

If it is leaning the engine out and I can't adjust the CP down, how can I set it up per the chart? I do have a plug in the access hole.

-Connect fuel pressure gauges & set for control pressure. Connect dwell meter for good measure.
-Remove vacuum enrichment hose from T and plug engine side
-Run car to temp. Do what is necessary to keep it idling.
-Reference high end of pressure chart for temp, adjust WUR hex screw until CP reads center of spec
-If fueling becomes poor and idle suffers, make small corrections to CP and adjust CO to compensate
-Repeat last 2 until control pressure full hot reading is correct
-Adjust CO per dwell procedure.
-Allow vehicle to completely cool, then recheck control pressure referenced at engine ambient temp. Ice it down if you want to check it even lower.
-If how & cold control pressures are withing spec, solve no further fueling issues with control pressure adjustments. Seal the bottom cap and leave it alone.
-Connect vacuum enrichment circuit to handheld vacuum pump and perform pressure checks per manual

If you still have fuel problems after this, it's not the WUR

[Helirich]

-Connect fuel pressure gauges & set for control pressure. Connect dwell meter for good measure.
-Remove vacuum enrichment hose from T and plug engine side
-Run car to temp. Do what is necessary to keep it idling.
-Reference high end of pressure chart for temp, adjust WUR hex screw until CP reads center of spec
-If fueling becomes poor and idle suffers, make small corrections to CP and adjust CO to compensate
-Repeat last 2 until control pressure full hot reading is correct
-Adjust CO per dwell procedure.
-Allow vehicle to completely cool, then recheck control pressure referenced at engine ambient temp. Ice it down if you want to check it even lower.
-If how & cold control pressures are withing spec, solve no further fueling issues with control pressure adjustments. Seal the bottom cap and leave it alone.
-Connect vacuum enrichment circuit to handheld vacuum pump and perform pressure checks per manual

If you still have fuel problems after this, it's not the WUR

I think you don't understand what I'm saying. I have never seen the control pressure below 58 psi. I have the adjustment set as low as it will go. I haven't checked the chart, but someone on this forum told me it should never be above 55 psi. So unless my high readings are a result of the gauge, it's bad. I'm going out to work on it right now. So maybe I'll have something to report tonite.

[Ron]

I've done it the way Luke does as a quick check if the engine is warm, and it works.

But to set the WUR after a rebuild, the following works best for me:
Begin with the engine dead cold, vacuum plugged.
Using a laser gun, aim at the seam joining the WUR and valve cover.
Find the pressure for that temp in the chart.
Setup for Primary pressure check. (If it's off, you are wasting your time.)
Start the engine.
Primary pressure should be 75 psi (+/- 4).
If OK, immediately switch to Control pressure. (Expect it to run ruff.)
Control pressure should match value previously found in chart. (Expect ~40 psi@~85F)
Compare the pressures with the chart as the temp rises.
The pressure should stop rising at 52 psi (+/- 3), 104F.
If OK, follow the vacuum checks listed.

If something goes wrong or you have to make adjustments, let it cool completely and start over.
Confirm all basic settings (timing etc,) then set CO.

[Ron]

I think you don't understand what I'm saying. I have never seen the control pressure below 58 psi. I have the adjustment set as low as it will go. I haven't checked the chart, but someone on this forum told me it should never be above 55 psi. So unless my high readings are a result of the gauge, it's bad. I'm going out to work on it right now. So maybe I'll have something to report tonite.Yep, the manual shows 3.8 bar = 55.114343 psi as max.
58 and warm follows it running lean, as suspected. But again, it doesn't make sense that it would start (at 80 something?) and run so well until well after it hit 104 and surely not for several minutes at 150 afterwards (before wimping out)...

[FABombjoy]

Something about the rebuild isn't right. Hard to say without full details, pics, etc.

I thought it runs rough when testing system pressure? I've been slowly purging all of my k-jet knowledge LOL

[Ron]

I thought it runs rough when testing system pressure? I've been slowly purging all of my k-jet knowledge LOL No, you are right -- It will definitely run ruff when set to Primary, if that is what you meant. After a WUR rebuild, it probably will (...not with a factory job as it should come pre-set.)

[Helirich]

So I removed the WUR from the valve cover and unplugged it. I left the vacuum hooked up and wrapped it up in rags and masking tape. Took it for the same drive as yesterday. I would say it is 6 miles out and the same back. Yesterday, it started running bad at mile five. Of course, I did drive around my yard for five minutes before I went out.

Today, I drove the out and back and it never ran bad. I pulled in the garage and bolted the muffler on. (I had been running with it off) This took a little time, but the engine never cooled completely down. Then I took it for another run. (The only change is the muffler)

Same course, out and back. It appeared to drive better than the first drive. This might have been just illusion because it didn't sound obnoxious. On both of these drives, I got it up to 75 mph and then backed off to 65 for most of the paved road. I pulled it in to the garage and plugged the WUR in, but left it wrapped in the rags. Out for another run.

This time I went a differnt way because it has a shorter route over dirt road. (Didn't want to keep dusting the neighbors) The engine was noticeably rougher running, but not as bad as yesterday. I was not forced to drive in second gear because of power. I pull in the garage and unwrapped the WUR and screwed it back on the valve cover. Out for another ride.

Took the short course to the pavement again. This time it ran rough and I thought about turning around. Then it kind of "cleared its throat" and seemed to get better. Out on the paved road, I got it up to 65. Coming back it wasn't too bad.

The best ride was the second. (WUR unplugged and insulated from the valve cover) but I can't say any of them were terrible.

Oh, and the temp never got to the line between the 100 and 220. I did have the AC on, so the fans would be running.

It seems to run smooth between 2500 and 3500. (And have good power) Is that where you guys drive it? It seems that 5th gear is just for holding speed. You can't go faster unless you go to 4th. Not sure if this car will do 88 mph in its current tune.

[Helirich]

So today I decide to take the car for a long drive. (If it would make it.) First, I filled the tank. I put about 8 gallons in and I could see the gas in the filler neck. Now if you do the math, I put five gallons in the other nite. So all told that's 13 gallons since that night. Of course I have driven some since then, but not allot. Since the tank is supposed to be 13.5, I had to be pretty low. The guage said alittle less than a quarter tank which would be 3+ gallons. Could it be that when it gets that low, it runs bad? I have the new fuel pump/gauge sender in one. Are those style senders good? I could put my old sender back in the tank if that works better.

Anyways, I drove to the fastenal. (About ten miles) No problem. Drove to a locksmith. (About 4 more miles) No problem except they don't have blank keys for the car. I drove to Oriely's and bought some wiper blades. (About 2 more miles) No problem. Drove to tractor supply and back home. The car drove great the whole time.

I assume the mixture is still not correct, but it must be close to run like this. Was the gas just low? I don't know. I'm not ruling it out. Maybe the WUR return line was clogged at the FD? The line was new and I rebuilt the regulator, but if it was clogged right at the FD, it would raise the control pressure. Then maybe driving around it got unclogged. Yesterday, it did feel like it suddenly "cleared its throat". All I can say is I'm grinning now.

A heartfelt thanks to all that tried to help me.

[David T]

You were very low on fuel. When turning, braking or accelerating you could have been starving the motor for fuel. With the OEM set-up if you have problems it usually happens when you are less than 1/2 because the pick-up hose has a hole or it is kinked or something else is wrong.

[Rich]

Nice to read about the progress. A car that reliably starts, warms up, gets you around town, idles and doesn't misfire makes other problems seem solvable.

Two follow-up questions to see how close you are to tidying this one up:

1. Did you notice the coolant temp reading during today's (successful) runs? How close to that middle line between 110F and 220F is it after it warms up and the A/C is on?

2. Did it feel like it had 130HP? You mentioned "power loss" as a main issue some time ago. Good power now at all engine speeds?

PS, DMC sells blank keys for the car. They can cut the the keys there, too.

[Michael]

The thing about the new style pumps (especially with the OE sending unit) is they do not sit in a low cavity of the tank like they do in today's cars. In the DeLorean, they are very susceptible to running dry because the entire tank bottom is level. Any braking, cornering, acceleration, etc. can starve the pump if the fuel level is low. From now on, consider 1/4 tank low and 1/8 of a tank dead empty.

[Helirich]

Nice to read about the progress. A car that reliably starts, warms up, gets you around town, idles and doesn't misfire makes other problems seem solvable.

Two follow-up questions to see how close you are to tidying this one up:

1. Did you notice the coolant temp reading during today's (successful) runs? How close to that middle line between 110F and 220F is it after it warms up and the A/C is on?

2. Did it feel like it had 130HP? You mentioned "power loss" as a main issue some time ago. Good power now at all engine speeds?

PS, DMC sells blank keys for the car. They can cut the the keys there, too.

After that ride earlier, I went out again and put 60 miles on the car. Just driving aimlessly like a teenager. Lol

1. Coolant temp never got to that line. Had the AC on at first, but it cooled off out side, so I turned it to vent. I think as someone mentioned, the PO must have the thermostat out.

2. Hard to say what a 130 hp feels like, but I'm happy with it. I had it up to 80 mph, but than I got to thinking about my 7 year old tires. (Got new ones on the way from tire rack.) One time I was in 5th going 65 and I had to slow to about 50 for a bit. It started to feel like it was bogging out. I shifted to 4th and it still didn't want to go. I was thinking "here we go". I down shifted one more time and it picked right up. Back to 4th and it was "great guns" again.

I talked to James at DMC and he is sending me a kit to convert my doors to the same key as the ignition. I have no key code, but he is going to cut keys from a picture. That's the first I've heard of that.


The thing about the new style pumps (especially with the OE sending unit) is they do not sit in a low cavity of the tank like they do in today's cars. In the DeLorean, they are very susceptible to running dry because the entire tank bottom is level. Any braking, cornering, acceleration, etc. can starve the pump if the fuel level is low. From now on, consider 1/4 tank low and 1/8 of a tank dead empty.

On mine, I think 1/4 is real low and a sliver below that line is "can we coast to the station" time. Lol.

On that note, I've been running premium no ethanol. Do you guys ever put ethanol in yours? I use to have an old motorhome that ethanol melted the plastic gas tank. I sure don't want that. I have two stations in town that have no ethanol, but what if I'm on a trip?

Speaking of trips, would I be completely crazy to go to a "Cars and Coffee" 50 miles away this Saturday? (I know I drove more than that today, but I was never more than 20 miles from the house.)

[WHO1DMC]

I have no problems with ethanol on long trips. When it gets to the time to put it away for winter I start using non ethanol.


Dave B.

[Rich]

That's real good news about your 60 mile jaunt.

In reverse order of some of your points below:
a. No, it's not crazy to take the car to the C&C 50 miles away - as long as your recent trips have all been made without benefit of a battery charger.
b. Using 5th to accelerate from 50MPH is asking a bit much. 4th should be fine, if not fast, when you floor it at 50. The PRV engine has decent low-end torque. It will pull decently from as low as 1500RPM if you're not in a big hurry. You shouldn't be feeling any misfires or hearing coughs from the back under acceleration.
c. Assuming the sender and gauge are normal the thermostat may be missing or stuck open. With a "cool" thermostat I've seen them run about a needle width below that line but not much lower. Since it's cheap and easy go ahead and pop in a new thermostat (from a vendor, not a generic) and gasket to be sure you have the right setup. It's one less thing to worry about and there's nothing good about running the engine cooler than it was designed to run.

Have fun at the C&C.


After that ride earlier, I went out again and put 60 miles on the car.....

1. Coolant temp never got to that line. Had the AC on at first, but it cooled off out side, so I turned it to vent. I think as someone mentioned, the PO must have the thermostat out.

2. Hard to say what a 130 hp feels like, but I'm happy with it. I had it up to 80 mph..... One time I was in 5th going 65 and I had to slow to about 50 for a bit. It started to feel like it was bogging out. I shifted to 4th and it still didn't want to go.

Speaking of trips, would I be completely crazy to go to a "Cars and Coffee" 50 miles away this Saturday? (I know I drove more than that today, but I was never more than 20 miles from the house.)