fuel flow problems

[andy123]

Hello all; I have scoped this site before and it's helped me with a few of my problems...so I decided to get the elite membership and post a problem my ford mechanic is even stumped with.

My '01 XLS 4L had problems the odd time starting. During the warmer weather about 1 out of 20 starts would tough (19 out of 20 would fire immediately). Now after sitting in the cold overnight temperatures of 10-20F...the vehicle doesnt want to start at all. To get it started I would need to prime the accelerator to the floor just about....and even after it starts....if I take my foot completely off the accelerator....it stalls. So, lately I would need to hold the pedal after it starts for 5-10min at around 1000-1500 rpm until the engine is warms up just so it won't stall.

My mechanic checked scanner codes and none were coming up. He changed the fuel filter, checked fuel pump (and connections) as well as cleaning the air sensors. Still I get the same problem and he is stumped too. He has done all work so far for no charge so I am seeing if anyone resolved a similar problem. Any input would be appreciated. Thx

 

[Turdle]

You might try this

http://www.explorerforum.com/forums/showthread.php?t=84220&highlight=IAC+valve

Could be the engine coolant temp sensor , or ECT sensor (there are 2-one for gauge which you ignore here-and one for PCM, which controls fuel mixture to some extent)

Welcome to the forum, and thanks for your support. You'll find it is money very well spent.

 

[xFatcatx]

I had similar symptoms as you and after cleaning my IAC (the link jtsmith posted) all starting problems have disappeared. FYI, you didnt specify which 4.0 you have, the Link is for the OHV. If you have the SOHC the IAC is underneath the Black plastic intake cover (4 7mm bolts to remove), and also it does not have the black plastic cap on the IAC as the OHV does.

 

[andy123]

Thx for the quick responses. The IAC was cleaned 1hr before I posted this thread. I will need to monitor cold starts after letting it sit to see if this helped. If there is still trouble tomorrow morning I will get the ECT sensor changed as well (I think they are only $50). My mechanic uses a multi snap on scanner that wasent showing any codes. Maybe the $25,000 scanners at dealership might show something that less expensive scanners won't. I will goto dealership as a last resort if all else fails.

 

[Turdle]

Andy-are you sure you cleaned the plunger shaft well? Did it move freely back and forth?

 

[andy123]

Yes, he removed it and moved a part in there back and forth (I try not to breathe over his neck at all times ). He also disconnected battery for 5min so computer can relearn with that part clean. He thought along the same lines as you with the ECT as well...but won't replace a part unless he feels it is necessary. So if same symptoms are there tomorrow morning will replace ECT even though no codes are present.

 

[cjones101812]

your mechanic's scanner should show what reading the ECT is giving to the computer.

 

[andy123]

It's been a week now after the IAC was cleaned; every start has been good. I had to take in to mechanic 3 times before he cleaned this part (guess I can't complain too much, he did it all for free). If I posted on forum before getting it looked at, would of saved me lots of time (since it was the first thing mentioned).

 

[Turdle]

So do I get a cookie?