The Unsolvable Miss at Idle....

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
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: > : > > If you had your car at a dealer for $2600 of repiars and they : >couldnt fix : > : > > a stupid miss I'd say you have an extremely shitty mechanic. : > : >

: > : > I agree. the EGR valve and MAF are the firt things that any : > : > competant mechanic should check, then the timing chain, then : > : > the camshaft sensor. : > : : > : They wanted to charge me $2600 for a few repairs... like $1000 for the : > : intake gasket! Needless to say, it didn't quite happen.... : > : : > : Also, I have replaced the PCV valve. The cheap $2 valve was one of : > : the first things tried. : > : : > : I did pull off the EGR today and I noticed some drops of watery : > : condensation in it. Other then that it didn't look like there was any : > : sort of EGR part to clean. But I'm going to look into it tommorow : > : again. : > : : > : I don't know about the MAF, since it's not sending any engine codes... : > : but you never know. : > : : > : The fuel pump or fuel pump regulator seems possible based on some : > : other posts I've read. The best bet may be to bring the car into : > : somebody and have them diagnosis it.... any other ideas? : >

: > That watery substance is a mix of water and distilled : >alcohol/gasoline/oil. Probably more water than anything else really. : >

: > Again, I this doesn't sound like a recirculation problem or a MAF sensor : >problem. But hey...what do I know. : >

: > 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 : >

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: : Original poster: : : Throw out your Haynes manual. Useless book for any serious repair. Up the ducks : and get a GM shop manual. : : With that being said: : : 1) Your MAF can be checked by any parts store that deals in remanufactured : electronics. It can be sent out to their supplier for testing and functional : checking if you suspect a MAF problem. : : 2) A shitty air filter will cause MAF problems with paper dust insulating the : MAF and causing all sorts of trouble. Many times, you can use electronics spray : to clean it gently. : : 3) GM EGR valves on this and many models flat out stuff up and clog. The

4.3 : Vortec GM engines as used in Blazers of the S10 variety are notorious cloggers, : code setters and stallers. : : Many GM cars and trucks have EGR base plates that must be cleared out when : doing an EGR service as they will either cause problems or reset a light again. : : Fuel pressure should be checked with a reliable hand-held gauge before you damn : any parts being bad back there. This is an expensive and frustrating mistake if : you change a fuel pump that is not the problem. : : With that being said, start here and tell us what you find. : : : Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director : '80 Carousel Red Turbo T/A, 26k orig. : '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig : '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... : '80 T/A project car...

Good point Joe. Oil film on the sensor(s) can also cause problems.

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.)

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

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

well tim i have an 87 firebird that has the same thng happen but it only does it when it is cold... if you give it about 15 or so minutes to warm up the engine should be running smooth by then... and the sluggish feeling should be gone.... but my car has almost 170,000 miles on it and it still runs hard... you may also wanna try running high test gas and octane booster with some injector cleaner all at the same time and take it out and open it up on the high way to clean out your injectors good and see if that helps any.... i also upgraded to a set of 8 mm accell plug wires you can get them at advance auto for 24 bucks but most have to next day order them....

Reply to
C S

i don't see that that little oil drip is gonna cause a miss and your theromstat will solve your heat problem more than likely but again i don't see where that would have anything to do with a miss in the moter

Reply to
C S

i agree with martin it doesn't sound like the maf.. when my maf went bad it would change the idel while driving it would rapidly go up and down until you started driving again... this is something that is happening at start up...

Reply to
C S

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

Brake booster or the check valve/hose coming from it to the intake.

You're onto the source of the problem. That will DEFINITELY give you idle problems like that if something is cracked. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...

Reply to
Bigjfig

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