Delorean rough cold starts till the Frequency valve kicks in.

Hi I just want to so thank you to this site. By D would still be in the garage if it was not for you.

So here is where i am at. I am having a problem with my cold starts, and after it has been sitting for a while. I start it and then i just dies out. If i play with the gas peddle it will sputter for me(about 1 minute) then once i hear the frequency valve kick in, the car start running correctly.

I have replaced the fuel pump, accumulator, fuel filter, o rings in fuel distributor and even added a second check valve by the fuel pump. I Cleaned the warm up regulator. I even took it apart and clean the o ring diaphragm inside. Put it back together and that helped a little. Then i tried adjust the mixture control valve right next to fuel distributor. (1/6 turn cw) This helped when the moter was warm, but made it worse when the motor was cold.

The car had been to a garage once to have the mixture adjusted and this made it pass CA smog. So i think the distributor is ok with its settings.
I clean the idle speed motor and made sure if was free moving. Then i tested it and made the flap inside move.

I am not sure where to go from hear. Should i clean/replace the frequency valve? Or is it the lambo board not sending a signal to the valve?

Thank you for the help

The frequency valve should be buzzing when the motor is running, hot or cold. Try removing the plug on the frequency valve and reconnecting it several times. That may be enough to clean the contacts up and make it work even when cold.
David Teitelbaum

1/6 of a turn is quite a large change. Typical you get less than a 1/4 from full rich to full lean (frequency valve changes from 10 to 90% duty cycle).

Hey nameless guy - why don't you tell us your name ?
I think this is the minimum you gotta do when you ask for help.


OK you checked the idle motor ? but very often the idle ECU goes bad, too.
I have repaired 5-6 of them in one year.
>50% it's just the power stage (BD335).

This sounds like leaking injectors to me. It only happens after the car has sat a for long time. All that fuel system work did not mention having the injectors cleaned. It would make since that the engine runs smoothly after about 1 minute once the injector lines have purged the air out. In my experience it takes more than 2 minutes @idle before the the lambda kicks in from a cold start. I've timed it several times.

Hi My name is Mark 10408

Leaking injectors make sense, what can i do to fix that? is it just cleaning them or do i have to buy new ones?

Is it a new fuel distributor i need?

Quote:

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Originally Posted by Some guy

Hi My name is Mark 10408

Leaking injectors make sense, what can i do to fix that? is it just cleaning them or do i have to buy new ones?

Is it a new fuel distributor i need?

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At the very least get them cleaned and check the spray pattern. They can do for you at DMCCA or any vintage european auto repair facility. Replace IF needed.

I would not worry to much about the FD at this point. That said, It is a Rebuilt HERVEY unit. All bets are off.

Ok so the problem with the frequency valve was a bad RPM relay. I just cleaned the contacts on the inside of the relay till i get the new one in the mail.

I turned the mixture adjustment back to were it was.

It still has a "sputtery" start. but now it sputters for a shorter time. the plate at the air intake takes some pressure to push it down. So i think the lines to the fuel distributor are ok.

Is it posiable the seals on the fuel injector lines are letting air in. ( i have never messed with them)

Leaky injector seals are a real possibility. So are many other places including the air tube for the idle motor that sticks into the bottom of the mixture unit. Cleaning and testing the injectors will probably help. You could also try some Techron injector cleaner. You are plugging the hole over the mixture screw after messing with the adjustment right?
David Teitelbaum

i am plugging the hole after i adjust it.

I have tried some other fuel injector cleaner.

I will try cleaning the fuel lines next.

You shouldn't have to clean fuel lines. I know there are all kinds of stuff on the market that calls itself fuel line cleaner, injector cleaner, fuel system cleaner and on and on. Of all of the stuff I have seen and/or tried, Techron is the only one I recommend. Once you have the system cleaned up and functioning, and you use the car regularly, you do not need to "clean" the fuel system. Besides all of the usual additives in modern gas, with the high alcohol content any deposits will be dissolved. Dirty injectors are going to have to be removed and cleaned eventually, even Techron will not clean up really dirty injectors but it will improve it. As for your bad cold idle, there are a LOT of things that can cause that besides dirty injectors and vacuum leaks.
David Teitelbaum

IDLESPEED REGULATOR SWTICH?


Dose anyone know where this is located? I keep looking for it, but it is listed on the schematic. I cant get my idle speed motor to work now

It is the switch that the throttle arm hits when the linkage is at idle. About center, top of the motor just under the air filter. Refer to section D:05: in the Workshop Manual. you should hear it click when the linkage is at idle and you can test it with a meter to verify operation. If it is not setting it is usually because the ball ends of the quadrant link get worn. Adjust it a little bit longer. The rod ends have little spring clips like the bigger struts and it works like a turnbuckle with left and right hand threads.
David Teitelbaum

Also ~25 times repeated - the switch does not turn the idle motor on, instead it tells the motor to reduce
idle speed down to 775rpm instead of >1000rpm.
Idle motor is always on as soon as the key is turned. you can feel it vibrating at 100Hz.

If your idle is too high - that might be the switch. If it is not holding it - motor seized or ECU shot.

Hi Thank you all for the help

So far i found out i had a bad RPM relay. This fixed the frequency valve not turning on.

I think my injectors are bad.
I went to clean them and there was no fuel in the line from the distributor. I tried cleaning 2 of the injectors and both had almost no fuel leak out of them when the bolt on top of the injectors were removed.

I Don't thing the cleaner i used was strong enough. After i connected the lines back i looked at the spray pattern and it looked ok when there was a lot of fuel, but didn't look good when there was a small amount of fuel going in the lines. It just kind of dropped out till there was good pressure.

I am going to try the bottle of Sea Foam injector cleaner, and if that dosen't work, i am going to bite the bullet and get new injectors.

I think this is the main problem i am having with my hot and cold start problems.

What do you think?

Being you are in Burbank, you might consider having DMC-CA do a thorough Force flush cleaning of the injectors before you condemn them. Cleaning is way cheaper than replacement. Also even new injectors can show the symptoms you described.

If there was no fuel when you removed the banjo bolt from the fuel injectors, the injectors are not the problem. You need to figure out why fuel is not getting to them.
David Teitelbaum

The car dose start and run.

and when i removed the banjo bolt from the top of the distributor(of the injector line), there was fuel pooled in the distributor.

If it is not the injectors, what are you thinking? I am open to anything at this point.