engine sensors?

[digglesworth]

Is there an idle air control sensor or something similar in the I5? My truck is still stumbling at idle. I just cleaned my MAF and TB a week or so ago and I think that's about when it started. I don't know exactly if it was before or after that. It was real bad over the weekend. I didn't disconnect the neg. battery cable when I did the cleaning. Maybe I should have but I didn't. I disconnected it today for about 30min and it seems to be a little better but still there. What's the H3 supposed to idle at? Mine looks like its at 600rpm at the most. If I rev the engine, it'll come down and stop around 750 but after a few seconds, it'll settle at 600 and start stumbling. It stumbles for a sec, catches itself and stumbles again. I don't want to take it to the dealer and let them rape me in diagnostics... There's no CEL which leads me to believe vacuum leak maybe... I got a new TB gasket to make sure that seal is good. I am gonna check the intake manifold bolts (don't really know where those are), take the spring deletes out and put the springs back in. I don't really know what else to do...

 

[digglesworth]

I took s short video of the tach bouncing but can't figure out how to get it on here.

 

[digglesworth]

Would a bad MAP sensor cause this? What about an intake manifold gasket?

 

[alrock]

Couple of recommendations:
1) Keep this topic in one thread. You've got the same subject in three threads, meaning the reader doesn't know what's been discussed already. You are not going to get good information by spreading this conversation out.
2) Get a code reader on there. Just because you don't have a CEL now doesn't mean there are not codes stored that could help determine the issues
3) Start with the easy things first, like returning the setup to stock vs. the spring deletes, swapping coils, running some Techron through the tank
4) Going to the dealer doesn't mean you're going to spend too much, not to mention that you also take your truck to an independent shop for the work as well, and they will likely have lower rates. Most troubleshooting is about an hour. You might even want a compression test done. If you take the time to get easy stuff out of the way, like returning to stock, then the mechanic can do a more focused troubleshooting effort.

 

[digglesworth]

If you'd like, you can delete this thread and I'll reply in the other one.

I ran a bottle of techron through it a few tanks ago before this started. I hope I didn't dislodge a particle into an injector...
Tomorrow I'm gonna pull the spring deletes out and check the vacuum lines from the airdoc pipe and from the intake manifold. I don't have the original throttle body so I can't put that on. Other than an airdoc, those are the only mods to the motor.
I'll stop in AutoZone and see if there's any misfire codes or anything stored in it.

If that doesn't solve anything, guess I'll have to start making phone calls.

 

[chaos254]

Are you sure all the connectors and everything are properly seated? What did you use to clean the maf?

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[3rdH3]

If it wasn't happening before, always go back to the things you last tinkered with. That is what a very wise man once told me except he didn't us the word "tinkered". Good Luck

 

[08H3]

I had a similar issue and it was loose manifold bolts. Be prepared for lots of cussing, time, and bloody knuckles. They are a pain to get to.

 

[digglesworth]

Are you sure all the connectors and everything are properly seated? What did you use to clean the maf?

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I used maf cleaner. Sprayed it down and let it dry. Used throttle body cleaner and an old tooth brush for the throttle body...

 

[digglesworth]

I had a similar issue and it was loose manifold bolts. Be prepared for lots of cussing, time, and bloody knuckles. They are a pain to get to.

I looked through the repair manual last night and saw what was involved. I was thinking about changing the intake manifold gasket. It looks like its gonna be as much of a pain as the thermostat. Says you gotta pull the drivers side wheel and wheel well outta the way.

 

[3rdH3]

I have seen mechanics check for intake manifold leaks by spraying carburetor cleaner around it with the engine running. If there is any leak, it will be ingested into the intake and cause the rpm's to increase. Just be careful if you do this.

 

[08H3]

... Says you gotta pull the drivers side wheel and wheel well outta the way.

That was the easy part! It gets worse from there. The carb cleaner trick mentioned above is the way to check before you get too involved.

 

[digglesworth]

How about this? Would this do it? :gaah:

 

[digglesworth]

I got a replacement coil pack from advanced auto parts to replace that nasty one. I put the original coil springs back in the other 4 and got rid of those supersparkz spring deletes. I replaced the throttle body gasket and checked all the other connections. I fired it up and it seems to be back to normal. I let it run for 10 or 15 min and the idle held pretty steady. I did hear a sucking sound coming from the tube that comes out of the intake manifold just below the map sensor. It goes into the valve cover. (I forget the name of this particular pcv tube. I know there's 2. The other one comes from the intake tube into the cover.) Is it normal to hear a little bit of vacuum there? Can anyone verify that their truck does the same thing at idle? I don't know if there's a leak there or not. Doesn't seem like it but I don't wanna go get a new one just to find out its normal to hear that...

 

[digglesworth]

Well.... Scratch that... It's still doing it.
Called the dealer I get my oil changed out and he said he'd have it diagnosed within an hour. Looks like I'll be parting with $110, plus whatever it costs to fix it.

 

[4speedfunk]

A tip regarding the AirDoc:

I accidentally pulled my AirDoc tube off the motor. This can happen if you rev the motor while in reverse. When in reverse...the motor will torque up on the opposite side, and if the AirDoc is installed tight (with no extra slack)...it will pop right off. My 3.7L would barely run...and would not idle at all. I thought I had really screwed up. So I popped the hood...saw the problem...took the tube loose...re-installed it with some extra slack...and its been fine since.

P.s. That coil pack doesn't look too bad...but its hard to tell anything by just looking at them.

 

[digglesworth]

I pulled the airdoc off to access the coil packs and pull the TB to replace that gasket. Nothing was outta the ordinary there. Everything was still in place... That coil pack was completely covered in corrosion. Whether that was the culprit or not, I feel better that its outta there. I got everything put back together so the airdoc is still on and secure. I pulled out the MAF and gave it one more shot of MAF cleaner as a last ditch effort. It's drying now... I haven't put a scan tool on it so maybe they'll be able to pull a misfire code for a particular cylinder. The service guy said those coil packs are usually the culprits so I may have another one that's bad. Who knows. I'm gonna drink a few beers and try not to think about the potential outcome tomorrow.... :cheers:

 

[digglesworth]

Could it be a bad battery?!?!? I plugged my MAF back in and it was worse. It wouldn't smooth out at all at idle. I had the door open and the dome light was flickering everytime the engine was stumbling...... I'm doing a reset of the pcm and made sure the set screws were tight in the stinger battery terminals.

 

[digglesworth]

Well the dealer pulled a 302 code so gotta replace the number 2 coil pack. They wanted $218 for one. Nope... Ill be going back to advanced and getting the $70 one with a lifetime warranty. The dealer wants to run an injection system cleaner through it since it was missing and they're worried about the converters being damaged from the un-burnt fuel... But its gotta be running right first so he told me to go put a coil pack in it and bring it back.

 

[Big Mike]

How did this turn out ??

Mine is stumbling again at idle when its cold.. :no:

 

[chaos254]

Well the dealer pulled a 302 code so gotta replace the number 2 coil pack. They wanted $218 for one. Nope... Ill be going back to advanced and getting the $70 one with a lifetime warranty. The dealer wants to run an injection system cleaner through it since it was missing and they're worried about the converters being damaged from the un-burnt fuel... But its gotta be running right first so he told me to go put a coil pack in it and bring it back.

I work at a dealer and while we always recommend the injection cleaners, its definitely not necessary after a misfire. Might be a good idea to change all the plugs if you already haven't.

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[digglesworth]

How did this turn out ??

Mine is stumbling again at idle when its cold.. :no:

It seems to have turned out good. No more studder. Chaos is right. I probabably could've gotten by without the fuel system cleaning but with 81,xxx miles it certainly wasn't gonna hurt. Anything I can do to give my I5 a fightin chance is worth it to me. I would say to get a code reader and see if you can pull any codes like the misfire. The dealer pulled a misfire code then swapped it with a pack in another position. He pulled a 304 first... Swapped 2 and 4 and it popped the 302 so the trouble followed the coil pack.

 

[Big Mike]

It seems to have turned out good. No more studder. Chaos is right. I probabably could've gotten by without the fuel system cleaning but with 81,xxx miles it certainly wasn't gonna hurt. Anything I can do to give my I5 a fightin chance is worth it to me. I would say to get a code reader and see if you can pull any codes like the misfire. The dealer pulled a misfire code then swapped it with a pack in another position. He pulled a 304 first... Swapped 2 and 4 and it popped the 302 so the trouble followed the coil pack.

I'll hook my reader up tomorrow and see if it throws a code when cold.....thanks for the tip :thumbs: