Engine idle problems

[Bopat]

I have an engine problem, and nobody knows what to do, so I decided to ask for some help here...

When I start the car and the engine is cold engine, then the car is going good for 1-2 minutes, after that misfires, starts to shake and stops. After that it runs really badly 4-5 cylinders only, very weak.
When gets warm, little better, but idle is really bad, and often stops. Horrible to drive, right feet on gas, left on brake (automat)
What can be the problem?
Fuel pump? (last year changed to new since than has 6000 km max.
Or fuel distributor? We adjusted it, still no change, only fuel consumption is up to 17 liters from 10 liters.

Thanks for your help in advance

[Elvis]

Last night I had a dream - haven't heard of idle problems for quite a while :-P


Well, I'd suggest you start with checking fuel pressure lines from and to the CPR, checking the
spray pattern of the jets and so on.

Some cars with similar descriptions had fuel lines mixed up or the fuel distributor internally was bad.


Slovakia is not really known for Deloreans, who worked on the car and when did you get it ?

Greetings from Germany,
Elvis

[Bitsyncmaster]

Most likely some bad injectors or the FD is bad. I say that because after 1 to 2 minuets the lambda starts working and the one O2 sensor averages all six cylinders for proper burn. You will need to adjust the mixture when you fix the injectors getting all good spray patterns.

[Bopat]

Well the car was commpletely renovated 3 yrs ago. And fine tuned by Ed in Delorean Europe last year. Everything was working good until this year I went to Belfast with the car. On the way back the water leak was too much so I had to leave the car in Germany to Deloman. They fixed the car water and other problems. The engine was partially opened, but only the top because some water leaks there.
After I got home the car started not to work properly.
They said that they did not modify anything in the engine. Which can be true, as the car worked another 800 km, it got broke only when I got home, and I was parking the car...





Last night I had a dream - haven't heard of idle problems for quite a while :-P


Well, I'd suggest you start with checking fuel pressure lines from and to the CPR, checking the
spray pattern of the jets and so on.

Some cars with similar descriptions had fuel lines mixed up or the fuel distributor internally was bad.


Slovakia is not really known for Deloreans, who worked on the car and when did you get it ?

Greetings from Germany,
Elvis

[Bopat]

Most likely some bad injectors or the FD is bad. I say that because after 1 to 2 minuets the lambda starts working and the one O2 sensor averages all six cylinders for proper burn. You will need to adjust the mixture when you fix the injectors getting all good spray patterns.

Hmm
Everything is new, not older than 2 yrs... not too good :(

[Bitsyncmaster]

Hmm
Everything is new, not older than 2 yrs... not too good :(

You need to pull all six injectors and do the spray pattern test. As Elvis suggested, check fuel pressures first just in case that is your problem.

[David T]

You need to pull all six injectors and do the spray pattern test. As Elvis suggested, check fuel pressures first just in case that is your problem.

Make sure the frequency valve is buzzing. Check for vacuum leaks.

[81dmc]

Last night I had a dream - haven't heard of idle problems for quite a while :-P


Well, I'd suggest you start with checking fuel pressure lines from and to the CPR, checking the
spray pattern of the jets and so on.

Some cars with similar descriptions had fuel lines mixed up or the fuel distributor internally was bad.


Slovakia is not really known for Deloreans, who worked on the car and when did you get it ?

Greetings from Germany,
Elvis

+1 on spray pattern test and fuel line order.

Since the "top," presumably the intake manifold, was removed, fuel lines could have been contaminated and/or mixed. You just have to go down the list to be certain.

[Bopat]

Weeks just passed and still can t find the mistake.
What we found out: engine is not getting enough fuel. We found that lambda is not working,doesn t get any signal/power.
We removed ECU and tested it, but that s working OK.
What else we can do? Check cables? I m going crazy slowly, the local mechanics are not exactly on the top... :(
The problem is the same. When I start the engine, is working prefectly. After like 3-5 minutes starts to slow down, the engine is getting less and less fuel, and stops.
If I spray fuel in the engine is working perfectly, straigh away has good sound .
What can be the problem???
What should we check? Any ideas?

[Bitsyncmaster]

Weeks just passed and still can t find the mistake.
What we found out: engine is not getting enough fuel. We found that lambda is not working,doesn t get any signal/power.
We removed ECU and tested it, but that s working OK.
What else we can do? Check cables? I m going crazy slowly, the local mechanics are not exactly on the top... :(
The problem is the same. When I start the engine, is working prefectly. After like 3-5 minutes starts to slow down, the engine is getting less and less fuel, and stops.
If I spray fuel in the engine is working perfectly, straigh away has good sound .
What can be the problem???
What should we check? Any ideas?

Two very common problems with lambda not getting power

1) Bad RPM relay.
2) Lambda relay is the wrong type (someone stuck in the wrong relay)

[David T]

Two very common problems with lambda not getting power

1) Bad RPM relay.
2) Lambda relay is the wrong type (someone stuck in the wrong relay)

The Lambda system adds fuel as required to get the most accurate A/F ratio. Since it isn't working the motor is running too lean and your idle is bad. Check for power and ground at the Lambda ECU and make sure the frequency valve is grounded. There is a ground connection right by the frequency valve. Also you can try plugging and unplugging the plug to the frequency valve to clean the connections. Very often that is all that is necessary. Refer to section D:04:01 and there is a simplified wiring diagram for the Lambda system on D:04:12

[FABombjoy]

You can cut the troubleshooting tree in half with this test:

Hold the WOT switch down. Does the idle change?

If so: O2 sensor or O2 sensor wire
If not: Jetronic unit power, frequency valve, or unit power / wiring

[Bopat]

Two very common problems with lambda not getting power

1) Bad RPM relay.
2) Lambda relay is the wrong type (someone stuck in the wrong relay)
I'm going to try it from another Delorean this weekend. Hope that helps... But I kinda lost hope already...

[Elvis]

You said you tested some stuff and closed it out - how did you test it ?

How did you make sure it is not getting enough fuel ?

Did you pull the jets and check the spray pattern and let them spray in bottles ?

I am missing the details here. Sorry I do help to analyze stuff a lot at work and
very often people from all over the world give me completely wrong feedback.

If you think it is not getting enough fuel - get a pressure tester kit for a few bucks
on ebay and measure it. We had a similar problem some months ago with an Austrian
car and with the tester it was quickly solved. (in this case a bad fuel distributor)

Within an hour the problem can be found so keep us updated and get the tester.

Good luck and have fun,
Elvis & 6548