Check your grounds.
The ECU ground, the block to chassis ground, check the battery voltage and ground wires there. Grounds are very important and judging by the condition of your plug wires your grounds could be screwed.

Will do, is there any max resistance that there should be or just check for connection?

check the condition of the cables and clean the connectors and mounting surfaces. You wouldn't be to hard pressed to then use some dielectric grease for good measure while you're at it.

Bad grounds from the battery to the engine, and from the engine to the ECU are a possibility, especially since you were having a misfire issue with the stock ECU as well. Or a bad coil pack. Or plugs. A sticking injector.

Something is going on...

Have you done any VE tuning at idle as suggested above? It won't cure the root cause since you had a problem even with the stock ECU, but if it's being made worse by an incorrect mixture at idle you should be able to get it back where it was at least.

I am waiting on the VE tuning until I get the wideband O2 sensor. Is that detailed in the manual? If not could you give me a quick breakdown of the process.

With no wideband you can still tune the car at idle, just tune it for the lowest map pressure at idle.

I gave a quick breakdown of what I'd suggest for a quick idle tune above-- there's a good bit of info on tuning VE in the MegaManual at www.megamanual.com -- And in the MS1 Extra manuals that installed with your MSPNP.

Sorry, I forgot that it was up there. Now I have read the megamanual portion for VE and will try it out tonight. Thanks!

No problem man-- keep us posted!

Now VE tuning will happen tomorrow night. Should I install the new injectors and then do the VE tuning? Or the other way around? I also datalogged startup, some 1st 2nd pulls, and warm idle with pinging. How can I post those on this forum and do you want to see them (Jerry)?

Oh, and the grounds seem good except I did not check the ground pin on the ECU plug??

You're getting ping at idle? Something is definitely not right... like you may be very lean. 17-18:1

Feel free to shoot us the logs, include a link to this thread for reference.

As for the injectors-- don't change too much at a time. You've already got something to sort out here, I wouldn't risk adding anything else to the mix. Leave the stock injectors in place for now-- fix the current issue, and then move on. That gives you the flexibility to swap the stock ECU back in as well. Especially since you were also having an issue with it you may get to a point where it's best to swap it back in-- find/fix the problem, and then upgrade to the MSPNP.

Of course... the problem could be clogged injectors causing you to run lean and miss and/or ping... but I wouldn't jump straight to that conclusion. Get the wideband in there first.

skimmed back over this thread and didn't see anything about you having new injectors to go in but you are gonna wanna put them in first and then do the VE tuning. you're gonna have to do it anyway after the injectors. save some of the work.


edit: thought you meant bigger injectors, didn't realise you were trying to sort out a problem which you thought might be bad injectors.

So I upped the VE table around idle and got the RPM to stabilize very nicely. It only wavers by about + or - 10 RPM now. The missfire also seems to have stopped but I will find out for sure tomorrow when I drive to work.

The next tuning issue is that when I gass it pretty good from idle, in neutral, I hear a knock. Very metallic like valves or something. I tried raising the VE table in that initial rev area but could not get it to go away. It seemed to get a little better as I went up but not all the way. Any ideas on this? I just dont want to hear any knocking before I slap the turbo in.

I will also be putting in larger 440cc low impedance injectors tomorrow if all goes well. So any tips for that process would also help.

Thanks again for all of the help.

you don't hear knocking. you hear something vibrating. heat shield, wg flapper, dp hitting tranny... not knocking.

GL w/ project 440 LowZ. I'm running 440 HighZ RCEng's, and think that LowZ injectors would have been a better choice... But I already had the RCEng's so what ya gonna do.

Report back when you get the 440cc lowZ injectors put in. I have a set I'd like to get cleaned and put in mine when Ben's patience runs out, so let us know what you did to make em work. Thanks!

I'm interested in how the low-z's work out for you too-- wouldn't surprise me a bit if you need some additional grounding. You're running a MM9495, and the 94/95 cars have a bit better grounding on the factory harness than the 90-93 cars did, so yoube fine, but if you see resets, or misfires when cruising causing your tach to drop out for a split second, then your grounds are not cutting it and you'll need to add some. On the MM9495 model there's one additional ground built in on the middle connector without need for mods.

So no misfires on my way to work today, it seems to be running good. That clacking when gassing was definately in the engine. It sounds like when you almost stall the car and the valves clack....I think is the sound? So I am not sure how to fix it.

I will keep everyone updated on the injectors for sure!!

So Jerry, you are saying that I need to groud the MS better with one of the center pins? Or do I need to run extra ground wires to the block or battery? I will just do it for good measure.

Also, should I run the 4 of 6 injectors that match on pulsed flow or that match on static flow (cc/min)??

I think alot of people would be pretty interested to see if you could run low-z injectors without the extra grounds. I'm almost 100% sure you'll need more on a 90-93, but on the 94-95 it's up in the air as it's slightly better grounded from the factory. Not much, one extra pin, but it helps.

I'd run injectors that matched closer on pulsed flow as that's real world conditions...

If you need to add the extra ground, it's pin 15 on the middle connector on the MM9495 (bottom row, 7 over from the left, 2nd from the right)