High-load, low RPM misfire(?)

Car: ? 1995 Camaro Z28 (LT1) M6 with ~69k miles ? Hurst shifter ? SLP intake & exhaust (dual conical K&N air filters) ? Intake airfoil ? Performance Friction race pads - front (they dust too much) ? Performance Friction street/track pads - rear (I prefer these)

Symptom: When the engine is at low RPMs (~

Reply to
Wayno
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I also had this problem with a recently acquired V-6 (3.4) 95 F-bird. Around 1500-2000 Rpm in overdrive...the shakes/missing. It would also sometimes miss at a red light at idle. Dropping out of O/D would clear it , until it was under a load again in O/D.

My cure was replacing the plugs and wires....( 3 plugs were only in hand tight )

My guess is it was blowing by the plugs on my car under a load.

Hope this helps........Stan

Reply to
BAD 4 GOOD

"rbc" wrote in news:4738b.52150$ snipped-for-privacy@twister.nyroc.rr.com:

-O

Reply to
Omegaman

"> Correct me if I'm wrong, but I think that year LT1 has a distributor-less

You are in fact wrong. Lt1's use what it called an "OptiSpark" distributor. It mounts on the front on the timing cover, behind the water pump. This setup was used only on the LT1 and LT4 engines. If they used the standard rear mounted distributors in the 4th gen cars you would have to remove the engine just to change the cap and rotor. - Gary

Reply to
Gary - KQ6RT

LOL - I never even thought about that. I thought changing the plugs on an LS1 was a bitch.

Changing the distributor cap & rotor on an L98 93 Camaro: option a) drop engine option b) remove windshield and top of dash pad. Sawzall a hole in firewall.

Sometimes I miss my 70 Buick. Enough room to pull the tranny out from the top - no need to remove the engine. ;)

Reply to
Ray

distributor-less

Reply to
Zuhalter

Thanks for the suggestions guys. I'll get to work on this tomorrow after swaping the front brake pads. Do you think that I should still try to get an OBDI diag tool reading or just jump into replacing the plugs/wires and perhaps cap and rotor? Any suggestions on replacement parts (speciflically the plugs and wires?)

Thanks again, Wayno

Reply to
Wayno

distributor-less

Reply to
rbc

I found my service manual this weekend! Woohoo. Bad news is that it looks like changing these plug wires is going to be a major PITA. Have to take off the PS pump and drain the coolant! I think I'm going to call around to find out how much the local places will charge me to do this before I spend a whole weekend on it.

Anyone know where I can find a Tech 1 to borrow for a few minutes? Auto Zone has OBD readers but the will not link with my car due to the OBDII connector (I think). I'm currently in the Detroit area.

Also, I looked into replacement wires this weekend AZ had the MSD wires but I hear that they do not find into the stock guides. The other choice was Bosch, which also were custom wires. Any comments? Also, has anyone tried the Platinum +4 plugs? Are these worth the $ or are iridium (sp?) the better way to go? Thanks!

Reply to
Wayno

Darn, I was just quoted $695 for changing the plugs and wires by Midas. 6 hours labor!!! How much time should this take them to do really?

Reply to
Wayno

Reply to
bikerbob

The dealers in town charge $75/hour. Midwas is supposedly at $65/hour if I remember right.

I've been thinking about this issue that my car is having and am confused to the logic why this would be caused by either the plugs or wires. Wouldn't I have problems all over the RPM range if that were the case? Why only at high loads at near or at WOT? Just trying to get it straight in my head. Thanks!

Reply to
Wayno

High loads and WOT demand more from the ignition system. Therefore if your spark is weak then you will encounter a misfire.

-Zuhalter

Reply to
Zuhalter

I was able to change all my plugs and wires by getting to several of them from underneath by dropping the pipes. No need to do anything with the ps pump or coolant.

Reply to
The Man of Steel

Thanks.... I noticed that this is what was stated in the F-Body FAQ, I'm surprised to see that it conflicts with the service manual.

Question... If I get an 8.5mm wire will it fit in the looms? What about an 8.0mm? If no, how does one get around this? I hit the local Auto Zone last week but was lost at which plug wire I should purchase. I'd like to get the High Performance MSDs but I don't want to make this job any harder that I already know it is going to be....

Thanks!

Reply to
Wayno

Well I tried my luck chaning the plugs/wires yesterday. What a PITA. I ended up braking the first two bolts when I tried to take off the Y-pipe, even after soaking them with liquid wrench overnight. After that point i decided to give up since any more broken bolts would have left me with a car that I couldn't drive. Instead I ended up chaning the oil/ air filter/ PCV valve. Looks like I'll be paying a shop to do the plugs/wires for me.

Thanks for all your help!

-Wayno

Reply to
Wayno

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