**Background- This **** didn't start till I put on my new P&P throttle body. Thought a bad TPS/IAC, both are new AC Delco, still problem**

Well, I have a new problem. I think my MAF itself may have both legs in the grave.

**2001 Camaro SS, 136,000 miles, M6- SLP Lid, K&N, Smooth Bellow, SLP LM1 Catback**

For the life of me, I can't get my car to idle. It's constantly searching, so to speak. It's kinda scary though when it wants to hang around 3k. It normally wants 1600 though. To get it down, since it hangs there, I have to almost stall it out at a light to get it to stay down.

It'll come down to normal (850ish) for a second, then just starts going ballistic, like it can't find it. I initially though vacuum leak, but haven't found one yet. I then figured, ok, it must be a bad tps / iac, so I bought both brand new, both AC Delco, reset the PCM, and that's when it got worse.

Before the new IAC and TPS were installed, the highest it would go was the aforementioned 1600rpm. After, it would shoot to 3000. I then decided to check the MAF itself.... I was already 100 miles into a 160 mile drive, and just started to get into civilization again off the interstate, so I pulled over, turned off the car, unplugged the MAF, started and drove.

Guess what? MUCH better idle, and no searching.

Does this mean my MAF is shot?
Does it mean it could still be a vacuum leak and now the motor just isn't seeing it due to the disconnected MAF?

The car IS idleing better now. Not perfect, at all, but it doesn't climb and search. It stays around 950 - 1100. I also understand this to be nothing more than just stored fuel trims and what-not though.

This **** didn't start till I put on my new P&P throttle body either. It came from a sponsor....

I already blew money on new TPS and IAC. I don't want to throw new parts at it if they aren't the problem, like I already have. Just looking for some insight from those of you that have been there before.

 

I had an issue with this the other day, I thought I fried my MAF when i was cleaning my engine bay, did something similar, then I just yanked the battery out to "reset" the computer and made it re-learn idle..it was funky at first. but I at least hold an idle now, and better than before. I always start with the simple stuff first, and then work up to big stuff..
But I did see a thread IDENTICAL to this, but a guy drove over a big puddle and it fried his MAF, he unplugged it and it held better idle, so if it were me..find another MAF your size, preferably not having to buy it, and then just hook it up and see what happens...

 

Sounds like the MAF.

 

I figured it might get moved.... I tried, LOL.

Yeah, that's what I'm leaning towards. Any advice on a brand? Stick with Delco? Any of the parts store's products any good?

I just wonder if it isn't that TB I installed. I never had an issue till I changed it.

 

Is there a hole in the middle of the throttle body blade? Or are there any spots between the blade and the housing around it? I had an issue with hanging idle last month when I did my LS6 and P/P TB swap. There was a hole in the blade where a screw went. I sealed it up with epoxy and it cured it 100%. Of course a tune will help it even more.

 

At this point, with the ridiculous lack of communication between myself and the sponsor, I'm seriously considering just selling the TB and getting an S3, like I originally wanted. That is, if it's NOT the MAF.

When I get home on the 4th, I plan to just take it to Chevy, hooking it up to the Tech II and letting them tell me what's wrong.

I seriously need to get a damned scan tool....

 

Well, if it DOES wind up being the MAF, anyone have a name brand recommendation?

213-3457 is the correct part # for AC Delco? What about Delphi?

Just want to squeeze a dollar or two... Didn't know if anyone had any advice or suggestions on the parts store brands, or just stick with OEM.

 

Well, just bought a stock screened MAF from the classifieds with 35k miles on it.

Here comes my window-licking question for the day - When I put the new MAF in should I reset the PCM, or just plug and play?

I want to instantly tell if it works or not without the computer having to relearn everything.

Suggestions?

 

Up for suggestions to last statement

 

It will instantly know and run normal again.

I doubt its the problem though.

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Thanks for the reply.

From the description, what do you think the problem is? Vacuum leak, or a problem with the P&P TB?

 

I think the PCM is commanding the IAC valve to go full open, thats the only way, at idle, your rpm's can reach 3,000 rpm....with your foot off the throttle. And I didn't think a fully opened IAC could even reach 3,000 rpm.

Before you go any further......see if your throttle blade is sticking partially open. Not fully closing when you take your foot off the pedal.

I don't see how you can get up to 3,000 rpm....with your foot off the pedal. And the ONLY way your rpm's can jump up that much, or at all above idle setting rpm......is if air is getting into your intake somehow.

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Yep. See my post. Is there a hole in the middle of the T/B blade or cracks around it? You could have put the throttle cable on wrong causing it to be slightly opened.

 

The only hole that's in the middle of the TB is the one that's there from the factory. It's been ported and polished / half shafted, but the hole hasn't been expanded, nor is not closing all the way.

When I push in the clutch it will go down to normal, but then all by itself comes up to anywhere between 1600 - 3k. It doesn't "stay" there, it will come down, but only after about 5-8 seconds of being there. The throttle cable doesn't hang up.

Hopefully it's just the MAF. When I unplug it it does get *almost* normal. It stops searching, let's put it that way. Then again, maybe there is some massive *** vacuum leak I just haven't found yet....

 

Put a piece of duct tape over that hole and start it up and drive it down the block and I bet your idle will be fixed. After that epoxy it shut. You might still need to tune it to get it all the way down.

 

That's crazy. Why should I have to do that? It's sealing up just fine on the sides. It's not over-ported, and the stock hole in the TB has NOT been enlarged. Does everyone that has a P&P TB have to do that?

I didn't think I would need a tune for a TB. This thing is getting to be more ******* problem than it's worth. If the new MAF doesn't fix it, it's getting sold. I'll tune it when the headers go on in a few months. No sense in doing it twice.

I'm so far beyond being aggrevated with this thing. I'll find a stock TB to borrow, or I'll buy one in the classifieds after I do the MAF if it still isn't working. If the stock TB goes on and it works fine, then I'll wait till I get a FAST and a NW before I mess with this **** again.

It just amazes me nobody else had issues from the ones sold by the sponsor on here, and mine is all fucked up.

 

Just try it bro. It takes a couple minutes and if it resolves the problem then your frustrations will be over. If its not the MAF, then you know you have a vacuum leak somewhere.

I had to do it with my PP TB and LS6 Intake Swap. I literally stuck a piece of duct tape on it, started it up and the idle went back to normal.

Have you done the idle relearn in the PCM?

 

I did. I reset the TPS multiple times as well. But like LS6427 said earlier, what could cause my idle to climb FROM 850? Nothing is sticking. It's as if I have a built in cruise control, and when it does come down, it goes up to 3k all by itself.

New IAC (triple checked for O-ring), new TPS, both new Delco parts.... I'm stumped. I'd bring it to Chevy, but they see 2 aftermarket parts and would probably just finger point at those.

The car runs fine for about 5 minutes, then does it's own thing. If this was Trans Am, I'd call it Kitt for having a mind of it's own.

It's either:

1) Vacuum leak I haven't found (bad TB gasket? Hose that goes into top line on TB?)That's all that's been touched.

2) Bad MAF. Will know when the one I bought gets to me

3) Car just doesn't like the TB, or something is WRONG. I refuse to believe that just by opening the body itself up that it could cause the car to climb in RPM all by itself.

4) Burnt pin on PCM

This is going to sound like I'm throwing a tantrum, but I'm at the point of just tossing gas on it and burning the damned thing. I'm going to try, again, to get a hold of the sponsor and see if I can buy my core back as well. Then we can erase ALL doubt anmd perform a proper process of elimination.

 

Here's what another sponsor says about doing the epoxy mod.... WTF? I've never heard of this before-

"We fill the big air hole in the throttle body with epoxy and then we port it. This eliminates air disruption from the hole. That hole feeds air into the tube that connects to the throttle body and goes to the MAP sensor. If we eliminate that air disruption, you will have to install a new connection for that MAP sensor hose in the tube in front of the throttle body."

 

You know what, I have a stock ported TB and my 427ci made 500 RWHP. Aftermarket stuff sometimes is just not worth the hassle until you go for big power and cubes.

A rock hard piece of epoxy falling off and going through the engine and lodging in a ring could be a disaster. If you want to do it better and safer....take it to a welder and have him weld it shut. Probably charge you $10.00 for 2 minutes of work.

There is NO WAY in hell that the small hole in the TB blade can allow an engine to rev to 3,000 rpm, impossible. Only a "massive" vacuum leak can do that. Maybe check all the bolts on your intake, they have come loose on people and that does cause a sharp increase to up;wards of 3,000 rpm. Also, a large, long crack in an intake that when torqued from hitting the brakes or accelerating hard can cause it to take a bug gulp of air, really only noticeable on braking when the TB blade is closed though.......

There's really no other type of vacuum leak that can cause the rpm's to go up that high.

If your car was here I would figure it out. Do you have any F-Body clubs in your area where you can find someone that will help you out?

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