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Dec 20, 2006 | 11:12 AM

ACHANDLER

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Joined: Dec 2006

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cold start

i have a 94 explorer which is hard to start on mornings that are cold. we have already replaced the iac what is next?

Dec 20, 2006 | 04:48 PM

marragtop

Posting Guru

Joined: May 2002

Posts: 2,450

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From: Baltimore

Have you checked the fuel pressure? Try turning the key on/off 3 times before cranking it.

Dec 21, 2006 | 11:49 AM

Keith Smith

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Joined: Dec 2001

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From: Mason, Ohio

Quote:

Originally Posted by ACHANDLER

i have a 94 explorer which is hard to start on mornings that are cold. we have already replaced the iac what is next?

So far were chasing the same problem with my son's 99 4.0 SOHC. To date I have replaced the fuel filter, plugs, MAF and the collant temp sensor and did an induction cleaning. It still starts and runs rough for the first few minutes in the morning or after sitting a while. I tried the fuel pump (turning the key on and off 3 times) and that wasn't a problem either. Next, I will replace the plug wires and fuel filter (again). From what I understand, the last step (and likely the answer) is replacing the intake manifold upper and lower gaskets. $20.00 for parts and a good long day of work. I may have someone do this that has more time and tools than I do. I had it diagnosed and the codes said MAF and coolant temp sensor. That was about $150.00 in parts and a few hours of my time. Induction cleaning was a $35.00 kit and 1 hour of my time. Good luck. If I figure anything else out, I'll let you know.

Dec 21, 2006 | 03:58 PM

aquanaut20

Cargo Master

Joined: Aug 2003

Posts: 3,263

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From: BC Canada

Dirty/gummy injestors will inhibit atomization and therefore make it difficult to start, especially in cold weather.

Run some injector cleaner through a couple of tanks and use a fuel that has good detergents.

Dec 28, 2006 | 09:23 PM

Keith Smith

Senior User

Joined: Dec 2001

Posts: 201

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From: Mason, Ohio

Quote:

Originally Posted by Keith Smith

Well, we just got the Ex back from a local mechanic this afternoon. He put upper and lower intake manifold gaskets on it. It has sat for about 4 hours in 35 degree temps and started up just fine. No more rough idle at start up. He checked fuel pressure and everything seemed OK, then finally agreed to do the gaskets after he started it cold and spraying starting fluid around the manifold made a marked difference in the engine speed. I'll check it again in the morning when I go to work, but I'm 99% sure this has fixed the problem. There is still just a very slight roughness, but I'll replace the wires this weekend and expect that to clear up. If any of you experience the cold start rough idle problem, start with the intake manifold gaskets. I wish I would have. The guy only charged us $110.00 (including the 18.00 gasket set).

Dec 29, 2006 | 08:13 AM

aballard

Junior User

Joined: Jan 2004

Posts: 60

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From: Proctorville, OH

Sorry for this sort-of-hijack of the tread, but I am dealing with a warm idle engine shudder in another thread on here

https://www.ford-trucks.com/forums/5...tic-codes.html

and wanted to know about this fuel filter test you all are referencing. Do you just turn the key to the on position three time before starting? If so, what are you looking for? By the way, I have a 2003 SportTrac 4.0 SOHC. Thanks.

Dec 29, 2006 | 08:15 AM

aballard

Junior User

Joined: Jan 2004

Posts: 60

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From: Proctorville, OH

Quote:

Originally Posted by aballard

and wanted to know about this fuel filter test you all are referencing.

Meant to say "fuel pump." My bad.

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Dec 29, 2006 | 08:55 AM

Keith Smith

Senior User

Joined: Dec 2001

Posts: 201

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From: Mason, Ohio

Turning the key to the on position and back off a few times will cause the fuel pump to build up pressure in the fuel lines without starting the vehicle. If that seems to solve the problem of the rough idle at start up, it indicates that the either the fuel pump is weak and not pressurizing the system enough at the initial turn of the key or that the pressure is bleeding back out of the system to an unacceptably low amount. That could either be some type of check valve in the pump or a leaking injector or maybe even a fuel pressure regulator.

Whenever you bleed the system, like when you replace a fuel filter or fuel pump, the directions recommend turning the key to the on position a few times to build the pressure back up prior to starting. It helps get the air out of the lines I guess.