occasional rich condition

[jimbolin]

I have been having a problem with my ex going to a rich condition mostly upon start up.It has also done while running.I can tell it it will do it by turning key on and not trying to start,the fuel pump will run past prime and keep running.The cel will come and then go off and run great(have not been able to get any codes).What would signal computer to go rich before even starting?One other thing is that when it does do this it will not allow me to check codes because fuel pump will not shut off.

 

[Brandon96]

I may be able to get you started, If I'm understanding you right, I think you should check up on the fuel pressure regulator, if you have one, it may be that it is deffective and sending fuel right back to your gas tank or leaking fuel into your vacuum system giving you hard startups and rich mixtures.. if your experiencing those as well.

Let me go find the link real quick, but I chased a rich problem for weeks just recently.

EDIT - here it is
If you read through it, theres a bunch of tests you can try to see if your FPR is bad or not. That was on a 2nd gen OHV, as far as I know mine is the same as the 1st gen OHV's

 

[jimbolin]

Yes,I have read through all the fpr symptons.I have had on diagnostics and was told pressure was good.I did not receive any numbers though,so I will check myself.The one thing I did find reading all the posts is that the computer is controling fuel.The 2-3 sec. prime time is controlled by computer not pressure.I do not have any fuel in vac line but it does have quite a bit of pressure in the return.
Is it possible for the computer to sense the fpr is not regulating properly and then tell the pump to keep on pumping without trying to start?

 

[jimbolin]

Bump,with another question.This is bugging the sh#$%t out of me.Let me simplify,what would make fuel pump run continious when key is in on posisiton?It does not do this all the time.When it does this and I when I let run on it will some times shut off by itself and then will also start right up.

 

[MrShorty]

Is it possible for the computer to sense the fpr is not regulating properly and then tell the pump to keep on pumping without trying to start?

In a word, no.

Bump,with another question.This is bugging the sh#$%t out of me.Let me simplify,what would make fuel pump run continious when key is in on posisiton?

Wiring fault. Do you have a wiring diagram (even the one in Chilton's is adequate). Start with a fuel pump relay that is mechanically sticking closed. Then look at a possible short to ground between the coil side of the fuel pump relay and the PCM.

 

[jimbolin]

I was going to start looking for shorts tomorrow.Would a short there account for the rich condition as well?It seems almost like a sensor is telling pcm to flow more fuel when it goes in this mode.