Where is the CTS located on the 4.0 ohv

[Rhett]

It's good that you're doing the cheap and simple things first. You already cleaned the MAF and TB, so that's good. You already changed the plugs (and wires, I think), and fuel filter, too. Change the air filter while you're at it. Now I would check for vacuum leaks (look for cracked vac hoses, hoses that have fallen off, etc.) to explain your strange idle. The IAC (idle air control) valve could also be the culprit.

 

[sparky2263]

Already been done, any other ideas?

Was this right after the plugs, wires and fuel filter were done? Wondering if it was a one time occurence.

 

[firerescue251]

plugs and wires haven't been done yet. Got held up with the holidays. But the MAF was recently cleaned and a new K&N Drop in filter was added. i was going to change the fuel filter but the tool i needed was nowhere to be found. So that wasn't accomplished either. I need some specific tips on how to clean the IAC, and yes i have searched but have found nothing. Weird i know. And this problem has been present for about a month now, only occuring in temps less than 40 degrees. Just found out that if i give it gas while it is idling weird it will stall. I don't know if that helps any. This is really starting to piss me off!

 

[sparky2263]

Any MAF vehicle with a K&N is gonna need pretty regular MAF cleanings due to the oil getting on the MAF wire.

 

[Runnin'OnEmpty]

Firerescue, that does sound like a 'lazy' IAC to me. The IAC is held on by 2 bolts and an electrical plug; piece of cake to remove and clean. You can use carb cleaner or brake cleaner to clean the carbon off the pintle valve. Before reinstalling, give it a squirt of WD-40 on the other end where the electrical parts are located.

This should help your idle. If the problem recurrs, then I'd replace the IAC with a new one.....

 

[firerescue251]

So far so good. Replaced the plugs with the OEM Motorcrafts and acceleration rocks! Cleaned, once again, the MAF Sensor and the IAC so far no bad cold starts. One more question. Will a clogged fuel filter hurt my gas mileage? Thanks for all the help guys! IT HAS BEEN WELL APPRECIATED!

 

[firerescue251]

Cold start problem is still there. Kind of running out of ideas, and still wondering if a clogged fuel filter will hurt my gas mileage. Any ideas are better than no ideas. Thanks guys!

 

[sparky2263]

The clogged fuel filter can hurt gas mileage. It can also lead to cold start problems.

 

[mechanix]

Sounds to me you either have a vacuum leak or your IAC is going bad.

That is what I would be checking. What would be really nice would to get a scan tool and accuate the IAC and watch it move. If it is noisey or dosent move smooth it is junk. Also when you removed the IAC did you notice alot of carbon in the IAC? If so it might be stuck and a simple cleaning might not solve the problem. Another thing to check is maybe the passage to the IAC is plugged with carbon. This was VERY common on the 4.6 and 5.4 engines in the trucks and SUV's.

To check for a vacuum leak I would take some carb cleaner and spray it around the base of the upper and lower intake and any where else a gasket might be that leads to into the intake. If you do this and the engine starts to run REALLY rough then you have found the problem.

Keep us posted.

Eric

 

[DCExploder]

Cold start problem is still there. Kind of running out of ideas, and still wondering if a clogged fuel filter will hurt my gas mileage. Any ideas are better than no ideas. Thanks guys!

In my Chrysler van when the avg mpg dropped from 25 to 20 I knew it was time to change the fuel filter. Chrysler said to do it every 12-15K miles, but I needed to do it every 6K since I was using cheapo gas. The gas in the filter would run out black when I poured it back out of the inlet. As soon as it was changed, mpg would go back up immediately. I haven't changed it yet in my X, but I am sure it is due soon.

 

[firerescue251]

Ok. replaced the fuel filter getting a little better gas mileage and also checked for vacuum leaks, there were none found, but cold start problem is still there. any OTHER ideas?

 

[sparky2263]

If a customer were to bring in a cold start problem only, they'd leave it overnight so I could take a good close look at the parameters when cold.

I would suspect a TPS/CTS/base idle or ground issue.

 

[Runnin'OnEmpty]

Firerescue, just read through your original posts and I'd agree with Sparky that the TPS is a possibility. It's very easy to check with a voltmeter; basically you're looking for a smooth transition from about 1-4v on the signal wire when the throttle is advanced.