Engine fires, runs, then quits immediately

[82DMC12]

A couple weeks ago I blew one of the upper water pump hoses (the one that connects the pump to the passenger side head). It was about 15 years old, looked fine, pliable, but on inspection during removal, it had a crack on the inside. So, I decided it was time to go into the valley once again for a freshen-up and to replace all the coolant hoses on the engine. Everything went well and I did the following:

• Removed ignition distributor to replace the o-ring on the shaft (oily residue around the distributor) and new impulse coil. First time taking the distributor apart but it went fine and I was sure to mark the timing nut and the rotor position - such that when I dropped it in, the rotor turned and hit my mark. I think it's fine? Also replaced cap (DMCH) and rotor (Bosch from Rock Auto) as well as new plug wires (DMCH)
• Checked plugs which I installed this summer to make sure they look good - all look perfect
• Machined the Y-pipe surface
• Removed all three sensors from the Y-pipe for cleaning, the 3-way switch broke so I put a new one in (DMCH)
• Updated the heater pipe to the DPI version (no more metal snake)
• Replaced all vacuum lines
• Routed engine harness under the air meter
• Replaced all O-rings and gaskets to get into the valley including pipe of agony o-ring and FD o-ring
• New belts
• Thin coating of anti-seize on every screw, new washers for everything
• Replaced PPR o-rings with D-go kit

Got it all back together no issues last night and tried to start it - it will turn over, fire, start, but then quit right away. Prior to this work I had no starting or running issues so it's something I have done this weekend.... See the video below.

My questions/thoughts:

1. I checked fuel pressure with my K-Jet gauge and my primary and control pressures are correct, rest pressure is fine but I do hear the accumulator clanking sometimes after turning off the fuel pump. Don't really remember that before. I have not tried to check pressure while the car is starting and trying to run.
2. I have not checked timing yet - I haven't done this in YEARS so as a refresher, is it OK to check timing with the fuel pump off and having a friend turn the key so the engine and ignition is running for a few seconds while I use the light?
3. How far into the air meter should be the pipe of agony be sticking in? I can see it through the meter plate if I release the fuel pressure and push down on the plate - I will check this again but I know the pipe is in there, just might not be far enough somehow
4. Does it matter which wire goes to which terminal on the idle microswitch? It's possible I got the wires reversed but I don't think so. I have the ground on the bottom terminal and the power on the top terminal right now.
5. When I removed the brass pipe for the CSV from the intake manifold, for some reason there was a copper washer down in there (in the pit where the long screw threads into). It's not in the parts manual so I removed it thinking it can't serve any purpose like that. Was I mistaken?
6. Thinking back about everything, it's POSSIBLE I forgot to torque the spark plugs down. I know they are threaded in by hand using an extension but now I'm trying to remember if I hit them with the torque wrench.... I think this would create a bad enough compression problem where the engine can't run, right? I'm going to check this first when I get home after work.

Appreciate any other ideas based on the evidence provided!


https://youtu.be/ub1kBN1S7cY

[David T]

If it is shutting of as soon as you release the ignition switch from the START position, it could be one of two things. Either you are not getting ignition power in the run position or you are only starting and running on the CSV and as soon as that stops (and the fuel stops) the motor stops. To time the motor it has to be running. As long as you are close it should run well enough to time it. Check the wires to the ballast resistor, maybe you knocked one loose.

[82DMC12]

If it is shutting of as soon as you release the ignition switch from the START position, it could be one of two things. Either you are not getting ignition power in the run position or you are only starting and running on the CSV and as soon as that stops (and the fuel stops) the motor stops. To time the motor it has to be running. As long as you are close it should run well enough to time it. Check the wires to the ballast resistor, maybe you knocked one loose.

Yeah it cranks, starts, I let off the key, it sounds a bit rough, and immediately dies. Once when I tried it, it ran for a couple seconds before dying but I couldn't get it any gas to rev it up before it quit.

OK I'll check the ballast resistor and the coil spade wires again. I was also thinking about the CO screw - I did not touch it during this rebuild but I did separate the halves of the meter to clean it out and used carb cleaner to get all the residue out of the lever and such. Maybe I'm running on CSV only and I need to adjust the screw to get the injectors to open up.

Remind me again - best to get the injectors in jars, jump the RPM relay, turn the screw until they spray, then back off until they just barely stop with no drips? And then it should be pretty damn close and I can use my dwell meter to dial it in once it's running. Maybe when I replaced the o-rings on the PPR, that somehow messed up the balance in the distributor. Or maybe I fixed a minor vacuum leak and that also messed up the balance.

[82DMC12]

Here's a picture prior to adding the fuel injection so you can see what I'm working with. Everything is pretty clean and it's not bad to poke around.

271656748_1122031091956285_7549321700104800630_n.jpg

[82DMC12]

By the way, prior to buttoning everything up on the engine, after I installed the FD and reconnected the feed and return lines, I had all the injectors out and I jumped the RPM relay to pressurize everything. I wanted to confirm I had no drippage or leaks, and sure everything was bone dry. I didn't put them in jars or press on the plate because I had actually recently done that this summer so I assumed everything was going to be OK putting the injectors back into the engine.

Is it safe to assume, based on the video, that the ignition distributor is at least CLOSE to correct since it actually does start for a moment before dying? There are a lot of variables there and it was my first time pulling the dizzy out and taking it apart. But there are only three or parts and hard to put together incorrectly if you paid attention during disassembly. I checked the impulse coil with my meter and resting still it was around 600 ohm, and it changed as I spun the shaft. Used a vacuum pump to check the vacuum advance and that's working fine too. I know the cap is oriented correctly and it's snapped into place in the alignment tab. The electrical connection to it is plugged back in and tucked into the firewall grommet.

[Helirich]

If the ballest resistor is un wired, you will not get it to fire at all. I’ve never timed an engine with a light that doesn’t run. (It should run some if your close). I’ve not heard of adjusting the mixture that way. (Doesn’t mean you can’t) I’m curious to hear what the others say.

Edit, I just watched the video. I think the timing is close.

[82DMC12]

If the ballest resistor is un wired, you will not get it to fire at all. I’ve never timed an engine with a light that doesn’t run. (It should run some if your close). I’ve not heard of adjusting the mixture that way. (Doesn’t mean you can’t) I’m curious to hear what the others say.

Edit, I just watched the video. I think the timing is close.

That mixture method I described is a way to get the mixture close, in the ball park, so the car will at least run enough so you can get a dwell on it and set properly. It's how you set it up if you're starting from scratch or someone else F'd it all up. Makes sense since you know the injectors should not be firing or dripping when the RPM relay is jumped or it would flood the engine. But they have to be ready to spray as soon as the meter plate gets sucked downward. So a slight tap on the plate while the system is under pressure should make them spray.

[Ron]

A couple weeks ago I blew one of the upper water pump hoses (the one that connects the pump to the passenger side head). It was about 15 years old, looked fine, pliable, but on inspection during removal, it had a crack on the inside. So, I decided it was time to go into the valley once again for a freshen-up and to replace all the coolant hoses on the engine. Everything went well and I did the following:

• Removed ignition distributor to replace the o-ring on the shaft (oily residue around the distributor) and new impulse coil. First time taking the distributor apart but it went fine and I was sure to mark the timing nut and the rotor position - such that when I dropped it in, the rotor turned and hit my mark. I think it's fine? Also replaced cap (DMCH) and rotor (Bosch from Rock Auto) as well as new plug wires (DMCH)
• Checked plugs which I installed this summer to make sure they look good - all look perfect
• Machined the Y-pipe surface
• Removed all three sensors from the Y-pipe for cleaning, the 3-way switch broke so I put a new one in (DMCH)
• Updated the heater pipe to the DPI version (no more metal snake)
• Replaced all vacuum lines
• Routed engine harness under the air meter
• Replaced all O-rings and gaskets to get into the valley including pipe of agony o-ring and FD o-ring
• New belts
• Thin coating of anti-seize on every screw, new washers for everything
• Replaced PPR o-rings with D-go kit

Got it all back together no issues last night and tried to start it - it will turn over, fire, start, but then quit right away. Prior to this work I had no starting or running issues so it's something I have done this weekend.... See the video below.

My questions/thoughts:

1. I checked fuel pressure with my K-Jet gauge and my primary and control pressures are correct, rest pressure is fine but I do hear the accumulator clanking sometimes after turning off the fuel pump. Don't really remember that before. I have not tried to check pressure while the car is starting and trying to run.
2. I have not checked timing yet - I haven't done this in YEARS so as a refresher, is it OK to check timing with the fuel pump off and having a friend turn the key so the engine and ignition is running for a few seconds while I use the light?
3. How far into the air meter should be the pipe of agony be sticking in? I can see it through the meter plate if I release the fuel pressure and push down on the plate - I will check this again but I know the pipe is in there, just might not be far enough somehow
4. Does it matter which wire goes to which terminal on the idle microswitch? It's possible I got the wires reversed but I don't think so. I have the ground on the bottom terminal and the power on the top terminal right now.
5. When I removed the brass pipe for the CSV from the intake manifold, for some reason there was a copper washer down in there (in the pit where the long screw threads into). It's not in the parts manual so I removed it thinking it can't serve any purpose like that. Was I mistaken?
6. Thinking back about everything, it's POSSIBLE I forgot to torque the spark plugs down. I know they are threaded in by hand using an extension but now I'm trying to remember if I hit them with the torque wrench.... I think this would create a bad enough compression problem where the engine can't run, right? I'm going to check this first when I get home after work.

Appreciate any other ideas based on the evidence provided!


https://youtu.be/ub1kBN1S7cY

1. Maybe see if it will stay running with short spurts of staring fluid.
2. In the vid, the tach appears to show ignition while it is dying (see #1 above ;-).
3. If you can see the entire opening, it's probably not the problem.
(It passes through an o-ring and it's keeper. )
4. It doesn't matter which wire goes to which terminal on the ISM micro switch.
5. The long bolt goes through a copper washer, the bypass pipe, and then an o-ring.
(Check this out).
6. All else ok, if the plugs are hand tight, it would run. (Not good for the threads, of course.)

[82DMC12]

Ron, the CSV washer I was talking about was a copper washer that was laying flat on the bottom of the intake under the brass pipe and the long screw went through it. Made no sense and didn't see it in the parts book.



Well I haven't learned too much yet but I did eliminate a few things.

1. I finagled the Pipe of Agony and the associated elbow hoses and got it to go another centimeter into the air meter and also confirmed the o-ring is still in place. I think we can conclude there are no vacuum leaks between the CVS to the lower air meter.

2. Confirmed the large vacuum line is going to the passenger side rear intake (hose clamped tight) and the manifold vacuum to the three way switch on the Y-pipe is also plugged in.

3. Rechecked all vacuum routing - OK

4. Removed and reinserted all wires to the ballast resistor and the ignition coil - Seems OK

5. Spark plugs were indeed torqued to 14 ft lbs - didn't forget! Checked plug wires - OK

Not much luck. It still starts after three or cranks but then dies right away just like in the video. However now I can give it a bit of gas pedal once it starts and I can get it to rev with each press of the pedal, but it sounds weak, and of course dies as soon as I let off the gas.

I'm trying to eliminate vacuum leaks as a cause so I'm thinking about the places it could leak that I touched.

• Pipe of agony - checked and should be OK now
• W-pipe paper gaskets - checked
• W-pipe o-rings - now I'm missing the "Back Up Rings" 102282 and I think I've always been without them. I have the o-rings on the W-pipe and I tried to double-up the rings like suggested on DeLorean.com but I couldn't get it to go together that way. I ordered the back up rings from DPI and will put them in as soon as I get them.
• Air meter halves gasket - replaced this and used red spray-tack gasket sealant, tightened all cap screws
• Didn't mess with the meter plate or the CO screw but I did clean everything in there with carb cleaner. I did look at the plate with a light behind it and it looked perfectly even all around.
• Throttle spacer - cleaned with silicone spray, it's not damaged
• Cleaned throttle with carb cleaner, worked the decel springs and made sure they were seated properly before installing the throttle.
• Confirmed the throttle is indeed closed
• Two manifold ports on the rear upper parts of the intake manifold - hoses are on
• Six intake o-rings - replaced, didn't use any grease, put them in dry. Carefully added the intake manifold over it and tightened the four manifold bolts in criss cross. Looking at the head-to-manifold mating area it appears even and flush. I did lightly clean the manifold mate surface with a pneumatic wire wheel.

Not quite sure where to go next! I'm afraid I may have to tear back down to the valley again and check everything from the bottom up....

[DMC-Ron]

4. Removed and reinserted all wires to the ballast resistor and the ignition coil - Seems OK

I know your checked the ballast resistor, but you might do a very simple test to insure the white with yellow (W/Y) wire headed to the coil is getting +12 with the ignition switch in the run position. The car can start from the cranking power provided to the ballast resistor then drop out when the switch returns to the run position.

Ron