The Unsolvable Miss at Idle....

Well, I've got one more crack-pot idea, then it's to an ASE blue seal shop to get this thing fixed.

But, my oil sending unit leaks, and upon further usenet scouring, I've found out that my fuel pump is controlled by the oil sending unit. So maybe if my oil sending unit is broken it affects my car at idle because the fuel pump is getting screwy signals and leaning out my mixture?

What do you guys think... I hadn't heard of the oil sending unit doing things like this, but there seems to be some support for it. I don't knokw if it would do something so extreme as to give me like a miss at idle, but you never know.

Reply to
Tim Payne
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Hi Tim,

Let me add one more thing to check. It might me a long shot but I've seen it on two Camaro's like yours with the 3.4L.

Crankshaft thrust bearing worn causing erratic crank sensor signals. Its easy enough to check. Just use a small prybar to see if there is any endplay in the crankshaft. The hard part is - this is a major repair.

Reply to
David McNally

: > Wrong-o! Not only doesn't every car have a PCV, not ever car has an : > EGR...which you just described. : >

: > Which is why I asked the question in the first place. Don't answer : > questions you don't understand. : : Well, as far as I know, every GM 3100,3400 and 3800 series engine has one, : which is what the O.P. is having a problem with. : : Sheesh. You need to chill out. Newsgroup. Not real life.

Well, not only was your original answer wrong, but it came across as snotty. (Maybe just my own internal voice.)

Sorry.

But, like I said, I'm not as familiar with this powerplant as I should be so I'm just shooting at the hip on this one.

If it does turn out to be the MAF like Joe and a couple others have guessed, then it's a relatively easy and inexpensive fix. (Hell of a lot easier than timing, that's for sure.)

Martin '01 Formula - MTI Air Box Lid, K&N Filter, Hurst-6, SLP Cold Air Induction & Smooth Intake Bellow Corsa Catback w/Premium Tips '83 V45 Magna

Reply to
GLK9MM

: : > Wrong-o! Not only doesn't every car have a PCV, not ever car has an : : > EGR...which you just described. : : >

: : > Which is why I asked the question in the first place. Don't answer : : > questions you don't understand. : : : : Well, as far as I know, every GM 3100,3400 and 3800 series engine has : one, : : which is what the O.P. is having a problem with. : : : : Sheesh. You need to chill out. Newsgroup. Not real life. : : : Well, not only was your original answer wrong, but it came across as : snotty. (Maybe just my own internal voice.) : : : : Sorry. : : But, like I said, I'm not as familiar with this powerplant as I should be : so I'm just shooting at the hip on this one. : : If it does turn out to be the MAF like Joe and a couple others have : guessed, then it's a relatively easy and inexpensive fix. (Hell of a lot : easier than timing, that's for sure.)

Well...that's not entirely true either. Timing can be pretty easy if ye' know what you're doing. < 1hr. Parts can be a bitch though.

Martin '01 Formula - MTI Air Box Lid, K&N Filter, Hurst-6, SLP Cold Air Induction & Smooth Intake Bellow Corsa Catback w/Premium Tips '83 V45 Magna

Reply to
GLK9MM

To the OP.

Well, the oil sending unit if it does in fact tie into the control of the fuel pump could do it. If it's leaking, and the ECM thinks that oil pressure is low, or it is low, may then cut fuel as a safety measure.

In any case though, if it's broken, doesn't hurt to fix it eh? :)

Again, good luck with it.

Tony

Reply to
Tony V.

Got that right. Holy hell. $50-$80 a pop for these little components if you want the OEM ones. Adds up real fast.

Reply to
Joseph Oberlander

First Step, take the Hayne's to a used book store. Recope $1.50 of your money. Then get on E-bay and buy a used GM/Helm Factory Service Manual.

One cheep thing you should do, especially if you have over 50K miles is change the inline fuel filter. They cost any where from $6.50 to $25. Then try a good fuel system cleaner. STP makes a good one called "Complete fuel system cleaner". It smoothed out the idle on a 160K 93 Olds Cutlass (3.1) that I had. I run 4 bottles thru it in one month (I was being lazy). You could also have (don't laugh) dirty fuel injectors. Allot of shops will claim that as a last resort thing, but at times it actually does occur.

Other people have given good advice, and I'm not saying to do this over theirs. Yet a the fuel system could have low flow at low RPM's and not be notable, or bad enough to affect WOT or part throttle acceleration.

Charles

Reply to
Charles Bendig

At what point, mileage-wise, might one want to examine the MAF (to see if it's going or not)? I haven't really looked at mine and am now at about 30K miles.

~w~

Reply to
Weland

I haven't looked at the MAF, but I did replace the Oil Sending Unit which has seemed to help the idle a bit, as a mechanic who I talked to said it would.

I just noticed that my brake pedal is making a bit of "whoosing" noise when I push it. That seems like the most likely culprit for a vacuum related problem. I don't know why I never thought of the braking system.

My brake pedal is spongy from the top and then gets really hard after a little bit of movement. Does that mean I should look into the master cylinder or is the brake booster? Or could it be a hose is mucked up back there?

Thanks, Tim-

Reply to
Tim Payne

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