fastcamz28

Do any of you guys have a MSD 6 or 6A unit? Of all of the modifications (primarily bolt-on) I've made to my '94 auto with 2.43's, the MSD 6 unit was one of the best, if not the best, performance improvers. The multiple spark from idle (mine is 650 RPM) to 3000 provides immediate response w/o ANY hesitation, even now (94k since last tune-up). Hope this helps .

97WRAITH

A FRIEND OF MINE PUT AN MSD6A AND HE HAS NO HESITATION.GREAT BOLT ON. GOOD LUCK

fastcamz28

I meant MSD 6A or MSD6AL. Sorry!! Guess that's why I'm still a jr member

sixspeedcamaro

I just installed the msd 6a. I love it... but I still have that stumble or miss at low prms under a load. like from a dead stop or any gear around 2000 rpm. above that the engine runs great, no problems. I replaced my o2 sensors recently figuring it may be them causing the problem. no luck there.however when I unplugged my maf the other day, the car barely had the stumble or miss. I had a new opti put on about 4 months ago, along with new plugs, wires, waterpump, fuel filter, coil. it's still messing up... anyone have any other suggestions?

thanks

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Seabat

Replaced, Opti, plugs, wires, coil, tps, temp sensor, fuel filter, O2 sensors, map sensor, removed the cat, blocked egr, maybe some other things I have forgotten about.
No stumble when cold, only when warmed up.
All the above has helped, but not cured.


93Z M6 RED
B&M Shifter
egr, tbb, offroad pipe
low speed stumble

95Zdroptop

I also have the same problem but only after the car has been driven for a few minutes. I saw an (Air Temperature Module) on rksport.com that makes your engine provide maxium spark at all times. I am thinking about purchasing this item and was wondering if it actually works. And also when my car is in fifth or sixth gear at low and even high rpm's and I smash the pedal to the ground it hestiats a lot.

GA93FORMULA

Possibly need custom tuning (versus additional) of the ECM/PCM to compensate for the various induction and exhaust mods. Another possible culprit (in the hesitation off idle debate) is the ignition control module (that thin layer of heat shielding silicon grease behind the module does not last long since the module is mounted next to the hottest part of the engine (cylinder head). Good luck to all.

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93 FORMULA - Hooker LTs. Mufflex. Lakewood LCAs. BMR sfcs. 3.73 gears. Trans-go. B&M. Moroso. Taylor. MSD. SLP afpr. Nitto DRs. TA girdle. LS1 aluminum DS. 12.92 et.

95 Z/28 LT1

I am experiencing this same problem and have made a couple of posts in this forum too.

I see that nobody has checked the egr valve yet. Thats my next part to replace. I think it is sticking open and fooling the computer into thinking there is a lean mixture. It in turn is dumping more fuel.

I have already replaced everything that everyone else has, so the egr is next. $40 from Jason Chromer.

onebad93ta

maybe timing chain is stretched bad

PGR

My '94 also does this, but only when warmed up, though. When cold and in open loop mode, it runs great.

Also, it seems to be worse when the engine temperature is hot, after a lot of stop and go driving, with the temp gage at or above the half way mark (approx. 210 and above)

I've replaced the following, but with no improvement to this specific condition:

Opti, plugs, wires, O2's, CAT, fuel filter, EGR, Ign. modual.

I'm tempted to replace the coil, however other posts suggest this will not fix it.

Anyone????

Kody

We need an expert to chime in.

I just recently developed this same problem on my 97. When cold it is fine. After it warms up in stop and go traffic, like 210 and above, it is sluggish until 2000 rpms, then takes off like crazy.

I attributed it to excessive heat (210 - 220) so decided to flush and re-fill cooling system. While flushing and filloing, etc... my wp died, started weeping. I am just finishing the CSI now, so have not been able to drive it yet. I read a lot of other posts saying it is the coil. But, most of you guys have already done the coil with no avail. What is this grease you have to put on the wires? And the protective grease between it and the head?

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White 96 Z28 A4
K&N CAI w/custom scoop, Flowmaster American Thunder, Cutout, LT4KM, TB Bypass, 1LE Intake Bellow.

Black 97 Z28 M6
CSI Electric WP, Hypertech 160 Thermostat, TB Bypass, K&N Filter, 1LE Intake Bellow, !CAGS.

wildboar

replace the coolant temp sensors.. I think there's 2 .. they screw in the block..

if that doesn't work, hook it up to computer

PGR

Kody: Use Dielectric Grease (its clear) on the spark plug wires. It is non-conductive, and prevents the spark from grounding out along the surface of the plug's insulator.

Use Conductive Silicone Grease (its white) on the back of the ignition module. It helps transfer heat from the very hot ignition module onto the somewhat hot cylinder head.

BTW, I applied a liberal amount of conductive grease on the back of my ignition module when I replaced it, yet the car still hesitates off idle.

I'm tired of replacing everything on the car - Does anyone really know what is causing this hesitation???????

Jake77444

Im pretty sure hes right, I just had my fuel filter changed not even 2k miles and my car doesnt have that problem at all.

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1995 Blue-Green Chamaeleon Camaro Z28 A4
T-Tops, K&N Cold Air, Jet pro chip, Transgo Shift kit, Rebuilt Performance Tranny

troywg

PGR - I have the exact same symptoms as you. It's really making me mad. I auto-x my car and all of the conditions that make the problem occur happen at the auto-x. I originally thought it was the EGR - didn't help one bit. Spent $300 to put new plugs/wires in for tuneup - still didn't help. If you figure it out please let me know. Beginning to hate my car....errr....
'95 Camaro Z28

[This message has been edited by troywg (edited July 02, 2002).]