Smoking Delorean video hunting idle

[zimvsdib]

http://www.youtube.com/watch?v=UtiVvZ6Z1hE&feature=youtu.be

Hey Guys, Hope you all had a good 4th!!!!
I posted some progress a while ago on this and hit a new wall.

A few Moths ago
I took the car on a trailer for a show. While driving it around it was fuel starved a couple times and hesitated during accelerations, almost died on me once.
Got home unloaded the car parked it. It wouldn't start up the next week.
Since then i had diagnosed that the plunger in the fuel distributor was stuck. Would not move at all. I swapped it with a working distributor unit i own (new o-ring underneath) and did a few tune up extras as well.

Fuel system:
WUR-rebuilt, Feq Valve-rebuilt, idle speed motor-new
Injectors cleaned tested.
New Fuel filter.
Drained fuel tank cleaned it out. Replaced fuel pump with Hervey's power pump
new 02 sensor
(every fuel component is new or rebuilt accept hard lines, hoses, fuel lines, and fuel accumulator)
I also pumped fuel through the system before connecting it to the fuel distributor as a precaution.

Electrical:
New upgraded coil
New upgraded spark plug wires and plugs
New dist cap and rotor
RPM Relay Checked
New alternator

I bypassed RMP and checked that the spray pattern was good on the injectors and tested 3 spark plugs before a reassembled. The car turned over but didn't start.


The next day the car started up! How?(bugs the hell out of me when stuff like this happens) Anyway, now but i get a hunting idle followed by a suction sound and a white smokey exhaust. It didn't look blue to me. I don't know if its fuel or what.

Today
i started it again. There is no exhaust smoke today! but the idle is still hunting and there was a bit of smoke coming from the back of the engine. Under the diagnostic plug area around the crossover pipe. I tried to video it but it is very subtle although it smelled bad. What could this be? I felt down under the diagnostic plug and a thick wire off the plug heads in that direction. Also it seemed to get hard and brittle the further i went. I couldn't get any further since the engine was hot. Any ideas?

Anyhow. I took this video above and it shows the car starting up then i pan over to the exhaust. Like i said the white exhaust is gone now but the idle is still hunting like this. The Dash RPM gauges shoot from 5-20 and the Oil pressure goes from half way to all the way up to 80 as the idle hunts back and forth.

Should i adjust the air meter adjustment allen screw to help the idle? I haven't touched it yet since i put on the other fuel distributor.

-Eric

below is just a video of my spark test:
http://www.youtube.com/watch?v=x1Tmm2NNzgw

[Michael]

I don't see a plug in your mixture adjustment...that's one vacuum leak.

There is a lot to check before you go turning the mixture adjustment and idle setting. The first thing to do is find and fix all vacuum leaks. I bet there is more than one.

[zimvsdib]

I know, on my list. I haven't pulled the manifold to kill all the vacuum leaks yet. I need to get the car drivable to move it into a nicer garage first. Unfortunately i live in a condo and do all my repairs in a public open air garage. People must think I'm a nut when they see my vehicle on jack stands. Couple time the security guards said i wasn't allowed to work on my car there. I own the condo mind you….

Do you think this is just from a vacuum leak?

[Michael]

Probably not but there is no way to go further until the vacuum leaks(or any known faults such as a bad micro switch, etc.) are fixed. You can't do a proper dwell setting unless everything else is working properly.

[DMCMW Dave]

[QUOTE=zimvsdib;149370...was a bit of smoke coming from the back of the engine. Under the diagnostic plug area around the crossover pipe. I tried to video it but it is very subtle although it smelled bad. What could this be? I felt down under the diagnostic plug and a thick wire off the plug heads in that direction. Also it seemed to get hard and brittle the further i went. I couldn't get any further since the engine was hot. Any ideas?
[/QUOTE]

There is a small cover on the back of the head that covers the cam opening. Probably leaking oil and running on to the exhaust. Or a valve cover leak in that general area.

The wire is for a non-existent diagnostic connection. It can be ignored. Unless it's touching the exhaust and melting/smoking there.

[zimvsdib]

I have an extra microswitch that works if you think this is something i should try. I haven't noticed any issues with it working incorrectly, when the arm hits the switch for acceleration operettas accordingly.


Vacuum leak locations i will check right now.

1.all vac lines
2.pipe of agony at mixture unit
3.throttle assembly rubber gasket. (does anyone sell these replacements?)

…are there any other major leak points to inspect?

[zimvsdib]

There is a small cover on the back of the head that covers the cam opening. Probably leaking oil and running on to the exhaust. Or a valve cover leak in that general area.

The wire is for a non-existent diagnostic connection. It can be ignored. Unless it's touching the exhaust and melting/smoking there.



Thanks Dave. I'll check this out too, you might be correct. I think i see a greasy spot on the crossover.
I'm trying to find an image of the motor out of the car as a reference to find the point you are mentioning but it not easy. Do you have a picture of this area?

[Michael]

I have an extra microswitch that works if you think this is something i should try. I haven't noticed any issues with it working incorrectly, when the arm hits the switch for acceleration operettas accordingly.


Vacuum leak locations i will check right now.

1.all vac lines
2.pipe of agony at mixture unit
3.throttle assembly rubber gasket. (does anyone sell these replacements?)

…are there any other major leak points to inspect?

I just mentioned the micro switch as an example. You want to check the advance vacuum on the distributer, make sure the solenoid is switching from the dist. and the wur correctly and make sure it's actually pulling vacuum. Use carb spray to test mating joints.

I went through this a few months ago and I really did the know what to do or check until I just dived into the tech manuals and got a basic idea of how everything works. I'm not an expert by any means, but it did give me a basic idea of how the vacuum and idle systems work, then it just worked itself out. It turned out that I had:
A bad microswitch
An unplugged vacuum solenoid
A bad idle computer
An out of adjustment mixture. Probably the PO messed with it since the plug was missing which brings me to my last point...
A missing adjustment screw plug.

It amazed me that my car actually ran well with all this wrong. It was cold natured and had a inconsistent idle but that's all fixed now.

[NightFlyer]

Definitely a big vacuum leak somewhere - after you check all the hoses/pipes in the vacuum system, use carb cleaner while the engine is running to narrow it down and identify where the source of the leak is so that you can remedy it.

Exhaust smoke is hard to identify from the video - did it smell at all, and if so, like what?

If you think a piston ring may be failing or if the engine is starting to use a little oil, you may want to run a compression check on the cylinders, just to see what you're working with. A well maintained engine with good rings should have combustion chamber pressure on each cylinder of somewhere around 100-130 psi. Always run each check twice and do the check when the engine is cold for the most consistent results.

Best luck with everything :thumbup:

[zimvsdib]

You want to check the advance vacuum on the distributer, make sure the solenoid is switching from the dist.

A bad idle computer



Michael, thats a good idea, forgot about that carb spray trick for finding vac leaks.

2 things stood out in your reply. First can what is the idle computer? I have never heard anyone mention that before. Is it the ECU?

Also "make sure the solenoid is switching from the dist" Do you know a way to check /test this? Those old solenoids on the backs of the distributor seem like something that should have been replace a while ago. Again to your point , its amazing how these engines can run with so much stuff out of balance or not working. I think i heard if you take it off and blow into a chamber and it has resistance than it's good. ??? sound familiar

I'm going to order a few new ones anyway.

[zimvsdib]

chamber pressure on each cylinder of somewhere around 100-130 psi. Always run each check twice and do the check when the engine is cold for the most consistent results. :thumbup:
Thanks for the ideas, I think a compression check is in order. I just want to get my numbers now anyway. Incase i solve this but need to refers to my compression numbers later at some point. Can you recommend a tester? My initial thought is that harbor frieght might be a place to get one. I know the have cheap china stuff but hopefully they can sell a decent one, seems like a simple tool.

[zimvsdib]

Exhaust smoke is hard to identify from the video - did it smell at all, and if so, like what?


Exhaust smoke stopped when i started it this morning. I don't know why… it was the first time the car started in a while and i had been working on it for a few weeks.

It didn't smell like fuel just intense exhaust fumes.

[zimvsdib]

There is a small cover on the back of the head that covers the cam opening. Probably leaking oil and running on to the exhaust. Or a valve cover leak in that general area.

Dave is this black cap the area you are talking about an oil leak emanating from?

BTW these are not my engine. This is from a friends blog.

287042870528706

[NightFlyer]

Dave is this black cap the area you are talking about an oil leak emanating from?

That would be correct.

[NightFlyer]

Exhaust smoke stopped when i started it this morning. I don't know why… it was the first time the car started in a while and i had been working on it for a few weeks.

It didn't smell like fuel just intense exhaust fumes.

Probably vaporizing condensate that had built up in the exhaust when the car was sitting.

Could have been oil or coolant as well, but isn't necessarily indicative of a problem if it was.

Nothing to worry about - especially if you're doing a compression check for a baseline/reference, regardless.

Just remember to keep an eye on the oil/coolant level as you first start driving it again - or always, as I always do with this car. :smile:

[NightFlyer]

Thanks for the ideas, I think a compression check is in order. I just want to get my numbers now anyway. Incase i solve this but need to refers to my compression numbers later at some point. Can you recommend a tester? My initial thought is that harbor frieght might be a place to get one. I know the have cheap china stuff but hopefully they can sell a decent one, seems like a simple tool.

Essentially, it's just a calibrated pneumatic pressure gauge with a hose and a fitting/adapter on the end that allows the hose to screw into the spark plug holes. eBay is littered with made in USA ones. IMHO, gauges are something that you don't want to trust to Chinese quality control standards/practices. Especially when you can get the made in USA ones for pretty cheap as well :thumbup:

I personally have/use this one:

http://www.ebay.com/itm/Big-A-Engine-Compression-PSI-Tester-Gauge-Set-MADE-IN-USA-by-KD-Tools-/230735340409?hash=item35b8e5e379&item=230735340409&pt=Motors_Automotive_Tools&vxp=mtr

[zimvsdib]

Awesome. Thanks!


So i just did a few tests with some starter fluid. Here are the results


If you notice i had beeb working on the fuel injectors and spark plugs and distributor. That entire area of pluming by there was my focus.
First the pluming around the ISM and the CSV wasn't tightened down with clamps. They were on there but not tight.
Also the ISM was still not attached to the intake manifold.
I noticed that the CSV had a lot of play in it and when i looked in the other side i could see that there was a noticeable gap on its connection. Like it needs to be tightened down.
That o-ring and the o-ring on the pipe of agony are probably in need of replacement too.

I tried to arrange the connections a bit better, started the car and had a pretty good idle there for a bit. Of course it went right back after it shifted around. Then i sprayed some started fluid at the brass connection of the CSV's base. I got rpm increase.

I don't want to get my hopes up but this may be all i need to get going.
Of course to get to that connection i have to remove the air mixture unit to get under it. I really didn't want to do that yet. My plan was to remove the manifold and go through everything later this month but i really need to drive this car to a garage asap so i can preform those other repairs.

[NightFlyer]

Awesome. Thanks!


So i just did a few tests with some starter fluid. Here are the results


If you notice i had beeb working on the fuel injectors and spark plugs and distributor. That entire area of pluming by there was my focus.
First the pluming around the ISM and the CSV wasn't tightened down with clamps. They were on there but not tight.
Also the ISM was still not attached to the intake manifold.
I noticed that the CSV had a lot of play in it and when i looked in the other side i could see that there was a noticeable gap on its connection. Like it needs to be tightened down.
That o-ring and the o-ring on the pipe of agony are probably in need of replacement too.

I tried to arrange the connections a bit better, started the car and had a pretty good idle there for a bit. Of course it went right back after it shifted around. Then i sprayed some started fluid at the brass connection of the CSV's base. I got rpm increase.

I don't want to get my hopes up but this may be all i need to get going.
Of course to get to that connection i have to remove the air mixture unit to get under it. I really didn't want to do that yet. My plan was to remove the manifold and go through everything later this month but i really need to drive this car to a garage asap so i can preform those other repairs.

Sounds like you're on the right path :thumbup: