Re: [DML] Re: Fuel system revisited

[Martin Gutkowski <webmaster@xxxxxxxxxxxxxx>]

(Bit of cross-posting here, apologies for those who've read this already)

We had a customer with very similar problems yesterday. I fitted a new 
coil and a new RPM relay, as well as repairing a damaged pin on the 
idlespeed thermistor, replaced the broken full throttle microswitch and 
vacuum advance solenoid with a broken pin, all of which were compounding 
the problems by exhibiting poor starting and a lumpy idle. All of this 
made it a lot better but he was getting serious hiccupping at about 
4000rpm unless he backed off the throttle, which would then make it 
red-line smoothly, albeit slowly!

I suggested we look inside the distributor - I know I suggested this to 
you too Rich, and you confirmed you'd cleaned and re-lubed the bob-weights. When we pulled the dizzy out of this car, the bob-weights were fine _but_  one of the springs that tensions one of the weights was missing. Don Steger once told me that most DeLorean dizzys only have one spring. I've seen it before and that time, as this, no evidence of a broken or dislodged spring was found. However, by hooking up a spring from a spare dizzy (original DeLorean dizzy with two springs - btw the two are different), the problem disappeared completely, and our customer rang today to thank us for "transforming the car" and making it far better than he ever imagined it could be. 

I wonder if the timing being too far out can bugger up the output from the ignition ECU (grey/white wire) which in turn feeds the RPM relay - our customer's problems were not fixed, but appreciably altered by trying different RPM relays (by a previous garage). Imagine the fault in the ignition system causing the fuel pump to be cut in the rev-range where you get trouble - that'll make everything a lot worse!

Your experience that it works better when cold is also consistent - your distributor gets no vacuum advance when cold, and you get accelleration enrichment. But gets it when warmed up, the mixture is leaner and you will run some advance under light throttle.

Best Wishes

Martin
DMUK
www.delorean.co.uk


>
>--- In dmcnews@xxxxxxxxxxxxxxx, "cruznmd" <racuti1@xxxx> wrote:
>  
>
>>I have no idea why my car ran so well after putting the new ignition 
>>coil in yesterday, but that was not the cause of my problem. The car 
>>still starts far easier than it did before but now, again, it runs 
>>terribly.
>>
>>Symptoms are exactly the same: After 1/2 pedal, the tach jumps all 
>>over the dial, the car bucks and farts and nearly tosses me out of 
>>the seat. I lose acceleration until I back off of the pedal.
>>
>>All I know for sure is this: -SOMETIMES- the car runs better when the 
>>engine is cool. It has psych'ed me out 4 times in the last few weeks, 
>>thinking that I'd found the problem. 
>>
>  
>





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