I need a new mechanic!

[KYRangerDude]

Of course I'm the mechanic...and I use that term loosely...LOL

You guys are gonna hate me by the time I get this rust bucket up and going!
Please bare with me and I thank you ahead of time.

As stated in an earlier thread, my 2.9 idles rough at startup. I've changed plugs and wires. New air filter. Checked vacuum lines, well, checked to see that they were connected. After reading as many threads as I could find on here, thought I would check the IAC , MAF and EGR. Well, I couldn't identify or locate the IAC or EGR but found what I thought was the MAF. I took it off and didn't find what I thought I should. The heat wire(s). It was just a flat piece with a blue cup that had 2 notches in it. Underneath the piece on the housing that the throttle cable is connected to was a flat metal piece that went between the notches in the cup on the flat piece I took off. I attempted to remove the metal piece but it wouldn't come out...I thought the heat wires were attached to it, but I saw that it turn and it cause the throttle cable to move. So I took the 3-4 in hose that went to the airfilter off and saw a valve like in a carb, not the heat wire I was expecting. I then took my MAF cleaner ($9.46 a can) and opened the valve and sprayed into the housing behind the valve. Some black soot looking stuff ran out and I sprayed until it was clear (somewhat). I cleaned the flat black electrical thing and let everything dry off. (30 mins or so). Put everything back together...started it up and ( very rough start)...smoked pretty good....then settled down but still didn't help the rough idle. I'm thinking next is to replace fuel filter. Find the IAC solenoid and EGR and check those out. Also, as mentioned earlier...volt gauge goes up and down during this rough idle period. Could it be electrical? Don't know where to start looking electrically.
And may or may not be related...started it this morning and noticed the park light were on. Switch was not on. Turned key off and parking lights went out. May have a ground in electrical somewhere? Previous owner had been inside dash because the bezel was loose and cig lighter tray had been removed and partially re-installed. I saw a couple wires had been cut, didn't know what they went to...so I taped them up and re-secured tray and bezel. Guess I need to trace electrical. Any suggestions on where or how to start?

 

[holyford86]

If it's the truck in your info, it does not have EGR, or a MAF. Beyond that, I'm having a bit of trouble understanding exactly what you are asking.

 

[94xlt4.0]

ok the thing you pulled of thinking it was the mass air flow sensor is actually the throttle position sensor. the mass air flow is located at the other end of the air hose going to the engine. it gets bolted to the air box. you will only have it if you have a california emissions vehicle. if you have a digital camera take a picture of your engine compartment and i'd be happy to point out the sensors and everything you have questions on

 

[KYRangerDude]

Holyford I do tend to run on with my posts and go off on rabbit trails. I appologize. I never know when enough is enough. I try to explain my situation, but somewhere in the post I go off on another issue that probably isn't even related to the original intent. I'm having idle start up issues and I'm attempting to locate parts that could be the culprit. Only after 5-6 hrs online last night did I conclude that my motor doesn't have the items I'm looking for. So, I'm back to square one. I've been reading related posts on here and other sites and the IAC EGR MAF/MAP came up a lot in those posts, so I thought I would find them on my engine and check them.

94xlt As you and all the others are aware...I'm not much of a mechanic. Especially on the EFI engine. I've never owned one before. I've had plenty of the 2.0 and 2.3 carbs and can probably work on them blindfolded. In the area you mention, near the distributor ( which I think I learned, isn't a distributor) there is a part that has vacuum lines and electrical lines going to it. It's all rusted up and stuff. But I haven't touched it as I didn't know what it is nor what it does. I'll try to post a couple pics and hopefully you can help me locate/identify possible culprits to my idle issue.

 

[KYRangerDude]

Here's the thing I don't know what it is.

 

[KYRangerDude]

Here's something else that I might need to check.

 

[KYRangerDude]

I can take this vacuum line off and it revs up and settles down and runs smooth.

 

[WTF]

Here's the thing I don't know what it is.

This is your fuel pressure regulator. Make sure that the little hose going in the back of it has a good connection.

 

[WTF]

Here's something else that I might need to check.

This guy is your Idle Air Controller or IAC. Pop that joker off and clean it with your $10 MAF Cleaner.

 

[KYRangerDude]

COOL BEANS!!!!!

Finally have something constructive! Thanx WTF!!! Can either of these have anything to do with a rough idle at startup?

 

[WTF]

I can take this vacuum line off and it revs up and settles down and runs smooth.

This mo-fo is just a vacuum fitting with two lines. Take a hose off of it and it'll mess with the timing advance since the end nipple is connected to the Manifold Absolute Pressure sensor or MAP sensor mounted on your firewall. The other hose goes to the air filter box.

 

[WTF]

COOL BEANS!!!!!

Finally have something constructive! Thanx WTF!!! Can either of these have anything to do with a rough idle at startup?

Yes, these 2.9s are touchy when it comes to timing, spark, and being fed good oil. Make sure that you do your homework in the Tech pages here and read anything to with the basics or tuning. You'll be glad you did.

 

[KYRangerDude]

MAP? Follow the big hose to the end and there is the MAP? Could it cause a rough idle start up? Also, my exhaust manifold has a crack near the #4 cylinder. Could that cause a rough idle? And as a temp fix....JB Weld the crack?

 

[WTF]

Anybody else chime in if I'm way off but.....yes, the MAP will hinder the idle-redline rpms since our trucks use a "speed density" method to regulate how fuel and timing advance are applied.

 

[KYRangerDude]

Finally!!! I took the IAC off and cleaned it with my $10 can of cleaner and started the ole rust bucket and it idles perfect. Anyone with idle probs should do that first. Took maybe 10 minutes. Thanks Guys for all your help!