Cold morning Start and idle issues

[leodiecat]

Ok so I find out the hard way after buying my explorer used (102K miles) that in the morning when it is cold it will initially start, the idle will peak and then slowly the idle will take a dive until it dies. A few days ago the check engine light came on and I get 2 different codes: fuel trim bank one and fuel trim bank two condition. So far I have cleaned the IAC and the MAF sensor. I disconnected the battery to reset the check engine light. 2 days later...the light is back on and there is no change with the cold start problem in the morning. Where should I go from here?? Do I replace one of the 2 parts I cleaned or do I suspect the O2 sensors need replaced? I don't believe it to be the fuel pump. Any "words of wisdom" would be greatly appreciated.
Thanks!!

 

[2000StreetRod]

Which engine, what codes?

Which engine do you have (V8, OHV6 or SOHCV6)?

What specific codes were set?

I'm guessing they were P0171 and P0174 (system too lean banks 1 & 2). If you have a SOHC V6 then you probably are experiencing the intake leak from the gaskets shrinking and leaking when the weather is cold. Here's a thread that discusses the problem rough idle at cold start....help Here's a thread that shows how to replace the leaking O rings. 98 SOHC Cold Start Idle problem
Make sure that you don't have any hose leaks before replacing the O rings. You can spray an aerosol starting fluid or propane on a cold running engine to find intake leaks. If the idle speed briefly increases then you've found the area of the leak.

 

[bcboy4ca]

My 98 Explorer has the SOHC and I was having some cold start/idle issues. When I would fire the truck up in the morning the idle would spike and then the idle would fluctuate. I didn't have any codes or engine light. I replaced my intake gaskets and the difference is night and day, the truck fires right up and the idle is steady right away. The gaskets are cheap and easy to replace, definately worth the money and time.

 

[leodiecat]

Yes the motor is a 4.0 SOHC. Thank you both for the reply. I will start off by replacing the gaskets. I'll let you know if it works.
Thanks!

 

[leodiecat]

Just want to make sure my mechanic isn't trying to hose me. Keep in mind I haven't done the gasket replacement yet...I wanted to get a definite answer that it was the problem before spending the money. Anyhow, so I took it in to be diagnosed and they are quoting me $1100 to replace ALL of the injectors. Does this sound right or does it sound more like they are not sure so they would just rather place all and the above and hope it works?

 

[dmc80]

when you do the gasket job, check the injectors. most likely this is gasket problem. Most people over 100k miles have done this job.

 

[2000StreetRod]

injectors & cold temps

. . . Anyhow, so I took it in to be diagnosed and they are quoting me $1100 to replace ALL of the injectors. Does this sound right or does it sound more like they are not sure so they would just rather place all and the above and hope it works?

Since your problem only occurs when the engine is cold, it is not likely an injector problem. Usually when injector performance is heat related it is due to high heat not cold. You can buy many bottles of fuel injector cleaner for $1100!

I just did the 00M12 kit installation for about $60. It solved my cold start and idle problems. It took me about 10 hours but I took my time and spent more than half of that cleaning out caked on carbon. Or you can just do the lower intake manifold gasket change for less than $25 if you don't have any front driver side chain rattle.

 

[chapsdeva]

Just want to make sure my mechanic isn't trying to hose me. Keep in mind I haven't done the gasket replacement yet...I wanted to get a definite answer that it was the problem before spending the money. Anyhow, so I took it in to be diagnosed and they are quoting me $1100 to replace ALL of the injectors. Does this sound right or does it sound more like they are not sure so they would just rather place all and the above and hope it works?

Your mechanic is trying to hose you!:thumbdwn: Guarantee you if you just replace the intake gaskets you will be fine...you have classic symptoms of them needing to be replaced.

 

[Trefty]

Not to hijack the thread, but I'm having a similar problem and have changed out the intake gaskets. When cold the vehicle rarely idles properly after first starting but sometimes it will idle after cranking a 2nd time. Other times it will flat out die if I don't keep giving it gas for a few minutes. I'm thinking this could be the IAC valve, but wondering if there could be anything else that could cause this.

 

[gijoecam]

For the original poster, indeed, it's likely the lower intake manifold gaskets. Common problem this time of year, simple solution for any shade tree mechanic.

And yes, your mechanic is trying to hose you. I'd love to hear how he came to the conclusion that all six injectors failed simultaneously.

 

[leodiecat]

Thank you to everyone for your feedback. Yeah, I thought it was b.s. that all 6 injectors would need to be changed simultaneously myself. Goes to show that like I said, they did not know exactly what it was so they figure if they replace everything it should fix the problem. Just in case anyone is from the Seattle area do not trust Central Avenue Automotive!!! I would much rather do the gasket kit, with the help of my brother and give him a little extra cash to go towards body work on his Chevelle!!