Rough idle and stalling help needed!! | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Rough idle and stalling help needed!!

becker69

Well-Known Member
Joined
January 28, 2001
Messages
993
Reaction score
0
City, State
Centennial, CO
Year, Model & Trim Level
01 Sport Trac
Ok, my truck has been running like crud lately... well yesterday (on my way back from having my 'check engine' light code read) it started stalling at every stop!! RPM's bounce from 500 to 1200+ at a stop (when it runs). The guy at Autozone said the engine code read as "Lean bank 1 and Lean bank 2". I had figured it was the MAF and the dude concluded the same (with his explaination that there aren't too many things that would make both banks burn lean). I tried cleaning it; no joy. So I get the new MAF in, and still no joy (out $130 now). I cleaned the throttle body and air filter. No help. My neighbor says do all the plug wires, plugs and ignition coil, then see how it is. He seems to think I could have a cylinder not firing and that is why the computer is trying to compensate with the erratic reving. Is this possible or probable? I got the wires and plugs because I figured they're due anyways, I haven't bought a coil yet; I just don't want to spend $350 and still have it not fixed. I've researched this on here and still have the same conclusions.

Any other ideas? I can't drive the truck at all until I fix it!! :mad::mad: Thanks.

Man it sucks to be only moderately mechanically inclined:frustrate:banghead:
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





I dont know if this will help, or if its even accurate, actually Im basing this opinion on my knowledge of Japanese fuel injected engines. When I got the erratic idle thingy in my Japanese cars, it usually and always points to faulty servo gears in the throttle body. Since the gears are made of plastic, they can strip and loose the ability to hold idle even if the ECU tells it to hold idle at a certain rpm. what we usually do is rebuild the servo gears and all is well, rather than replacing the entire throttle body assembly. again I am basing this on the structure of Japanese fuel injected engines, I ust dont know if American cars use the same principle. good luck:)
 






Doug,

Have the fuel pressure checked before you spend anymore money. The fuel filter could be clogged or the fuel pump could be going bad. It seems my fuel pump needs replacing. It works, but its just not supplying the volume that it should be. And it causes the too lean on both banks.
 






Also check vacuum tube that goes to the IAC valve that is famous for developing cracks.
 






Thanks for the ideas.... where is the IAC located? Can I just go to any shop and ask them to check the fuel pressure or do I need to go to a certain kind of shop (I just don't know if I should try to drive it up to firestone or a similar shop?). I just had the fuel filter replaced in it about 18 months ago (~ 13,000 miles or so). Thanks a ton!
 






Thanks for the ideas.... where is the IAC located? Can I just go to any shop and ask them to check the fuel pressure or do I need to go to a certain kind of shop (I just don't know if I should try to drive it up to firestone or a similar shop?). I just had the fuel filter replaced in it about 18 months ago (~ 13,000 miles or so). Thanks a ton!
IAC = Idle Air Control valve. It sits right on top of the intake. The big vacuum tube that goes to it is famous for getting a crack in it and causing the too lean codes.

Any mechanics shop should have a fuel pressure gauge. One of these days I will probably buy one from Autozone. They will connect to the schrader valve on the fuel rail on top of the engine.

This is an IAC valve on an older Explorer, but it should look similar to yours.
3661iac_sensor_after_removing_black_cap.jpg
 












Thanks for the pic of the IAC... I located it; but I don't see any vaccuum lines going into it nor any fittings for any (there is an electrical plug out of it) and lower on the plastic housing covering the heads is a rigid curved rubber line that goes toward the drivers side and under the battery... is this it?

My IAC (on top of the intake) doesn't have a fitting - nipple- like the one in your pic.

I'll get a manual today and see if it's drivable to a shop to get the fuel pressure checked before I swap out any new parts.
 






Yeah, sorry. The vacuum tube doesn't connect directly to the IAC valve but to the part of the intake that the IAC sits on top of. Anyways, the Job 2 ST's are notorious for that tube getting a crack in it and causing a too lean CEL code. Yeah, that pic is from an OHV 4.0L motor I think. My IAC has no nipple either.
 






Cool, thanks. So the one I asked about sounds like the right one to look at for cracks..? Boy rough idle sucks... truck is undrivable due to loss of power (ie, brakes :() at inadvertent times and it can be a dozen diff. things!

Reading another post on IAC cleaning now before I go to work... maybe I'll try cleaning it (carefully) if the vaccuum line looks alright.
 






idk if this was my problem my cold air intake wasent seated properly and i fixed that and just reset computer and if not that i have a line on the battery side of engine that runs down below the battery that feels real dry and turns my hands black when i touch it so im hoping its one of these problems thanks for the pic and video john
 






Well I couldn't find a shop that would test my fuel pressure without charging me an hour of labor.... so I made an appointment at a Midas that is close by (since the truck is almost completely undrivable) to have computer diagnostics done on it to see if they can extract probable causes to save me a couple hours of troubleshooting. I am hoping for good accuracy while they are running it. I have to get it usable and I don't have a ton of disposable time. :(

I am hoping that they can at least help me narrow between causes. Any insight into getting computer diagnostics run? I realize that it will not be the end-all cure-all, I just want some help using the computer to diagnose.
 












By the way you can by a pocket scanner for 75 bucks (probably less than your about to pay for just one reading) and then you will have it forever, pull the codes yourself then use the website above to understand the codes.
 












Thanks for the links and info. I totally agree that buying the dignostic parts would be the best long-term way to go; the only codes that came up I had read by Autozone re; too lean....

The crappy part is I don't have a lot of time to troubleshoot codes, nor do I have a car I can run up to the store to get the parts needed. I hate to admit it, but in a way it's a $ vrs time issue and I HAVE to just spend the $ to get it back running. I don't mind getting dirty and learning, I just don't have the hours to pour into replacing parts as I go along until I find what it is. If I don't have good luck at the shop, I may be back at square 1 :mad::(

I saved the code site and I'll get an OBD-II reader in the near future.
 






johnstone already mentioned it - fuel filter
usually lean code indicates fuel filter to the parts store
-that's what they suggested for me
 












Thanks for the links to the cracked elbow information. I had the same three codes, so I cleaned the IAC valve. In the process I had to remove a black plastic cover, and when I had cleaned and replaced the IAC, I could hear a vacuum leak. I didn't know exactly where to look for the leak, and I couldn't isolate the sound as it is pretty close to the belt, so I was a little bit stumped. Seeing this post and the tendency for this elbow piece to crack, I will go out and check it, and hopefully it will fix the problem! Thanks!
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





That was it! I found the "crack" in the elbow... HELLO! I could fit my whole pinky into the hole that was there! I am surprised my truck was running as well as it was with that mess. Now I know why that whole area was covered by so much dust! Thanks for the advice!
 






Back
Top