'94 Z 6-spd. 125,000 miles. SLP Shorties & Loudmouth, LT4 AN Module, 1.6 Roller Rockers, dyno tuned (PCM).

***It started with Opti-like symptoms. Bought an MSD Billet (before I found out about its problems).
Also replaced wires (MSD), Coil (MSD) and plugs.
Ran fine for about 20 miles and started doin' it again.

After reading all of the naegative posts about MSD Opti's on this Forum, sent it back to El Paso and they said that it tested fine (they even retro-fit the bearing).

Re-installed - still bucking and missing.

Two days ago replaced all 8 injectors with LSx take-offs that I bougt several years ago.
It started and ran very smooth (yes, I used "new" fuel). Revved all the way to the limiter (6000) without a hiccup.

Tried to drive to get it inspected and it is just as horrible as ever.

I just finished a fuel pressure check - 42psi at idle, slight dip, then increase as revved.

I have "shot" the headers with a infrared thermometer and am getting fairy inconsistant temps from side to side, but also within a side - left bank was about 100F hotter than right (300 vs. 200).
I thought that maybe it was a O2 Sensor issue, but have cleaned and swapped them with no different results.
I've since decided that maybe the temps are skewed by ceramic coating?

Prior to installing the MSD Dist. (***) I had installed a NSX 100hp kit- sprays from the elbow (nitrous and fuel) and had it dynoed at Speedtec, here in Ft. Worth.

Regular 301 hp/328 tq, sprayed 404hp/450tq.
No A/F issues (computer re-programmed by Scott at A&S several years ago), but they did recommend a littel colder NGK copper spark plug.

I have triple checked the wires for correct connection and routing..

I think that about covers it.

Any suggestions would be appreciated.

Thanks,

Chris

 

Maybe if they put it into a 220 degree oven and tested it it would show a problem if it's heat related, they probably just plug it in and spin it up and say it works.

 

If I take it to a shop with a "scope", would they be able to determine the problem?

 

as long as the tech knows what he's doing, the tool is only as good as the person thats using it, look for someone that has a L1 ase "Advanced level engine performance" certifacation.