Issue with cold start.

[RichieSHO34]

Just as the title says, this problem just started about two days ago. When I go to cold start I have to give it a lot of gas then when it finally starts the rpm's go to 1000 then drop to about 500 and I give it gas so it doesnt die, but this only happens with cold starts and once its started it runs fine. What could be causing this, I was thinking oil in the plug wells? But I figured I'd ask the professionals

 

[RichieSHO34]

Nothing?

 

[Marccus]

MY '89 did this EXACT same thing. I replaced the fuel filter, the fuel pump, checked fuel pressure at the rails - OK, replaced the injectors, checked the compression and it STILL did this. Then mysteriously, the problem just went away! Beats the crap out of me what was wrong. :braincramp:

 

[Black Bart]

I will add on to this rather than start a new thread. My daughters car is doing the same thing. Car runs great other than when it is cold, only 40deg here, you will need to use the pedal to keep it running. After about 30seconds, it idles fine.
I thought I might try a idle relearn early in the moring when it is cold and see if that helps.
I do allow the fuel pump to build and stop before starting.
I have not checked fuel pressure yet though. If it was down a lb or two, could this cause the problem? My thinking is that cold start and initial idle are controled by nothing but preprogramed memory with input from a temp sensor. If the regulator wasn't giving the correct preassure, that could mess up cold start mixture? The rest of the system would adjust for the lower pressure?
My second thought is to find out what sensor the computer uses to tell it what temperature it is outside for initial startup. This could be dirty or just bad and giving the wrong readings. I just havent had time to look through the book a friend gave me from ford. Like most people, I went right to the computer hoping it would save me time because someone else has fixed the same problem.
Thanks
Scott

 

[220ksho]

Could be a number of things including:

Dirty MAF
Sticky IAB/IAC valve
Fuel pump/filter
Dirty injectors

I would definitely: clean the MAF, clean the IAB valve, reset the idle, and as Black Bart says, let the fuel pump cycle before starting. Sometimes, I cycle it twice. And buy quality premium gasoline. The oil in the plug wells would cause it to run rough and miss a low rpm, but probably is not the cause of sluggish starting. You should definitely remove the oil though.

 

[RichieSHO34]

Yeah today after school I kinda came to the conclusion that it was plug well oil and heres my theroy, There's an abundance of oil dripping from the plug wells into the cylinder head, this causing a higher flash point i.e more gas so i have to give it gas, after it starts i rev it and there is black smoke coming out for the first couple revs then it stops. So im going to try and get my plug wells dont this weekend and report back

 

[itwonder]

At most, plug well oil will cause a puff of blue smoke upon cold start. I think your problem is elsewhere.

 

[rubydist]

plug well oil does not get into the combustion chamber unless you have another problem too.

plug well oil does cause plugs and boots to short, reducing spark intensity. this can lead to lack of power and other similar issues.

cleaning the oil from the plug wells is pointless unless you change the valve cover gaskets so it doesn't immediately leak back into the plug wells. and you need to change plugs and wires too. be sure you clean the oil out of the plug wells before you remove the plugs, so that dirt and oil doesn't run down into the cylinders.....

 

[Black Bart]

bump for a question?

 

[RichieSHO34]

What?

 

[Black Bart]

Mine was the Iac motor, I had two used clean ones that did the same thing. Now I still have an intermittent idle issue and a light on after deaccelleration.