MSPNP 94-95 New Install Issues
 

So I just installed my new MSPNP and am experiencing misfiring. I think that I had a tiny on the stock ECU but nothing this bad. Before it was just a slight jiggle every once and a while while sitting at a light. Now with the MS installed it makes the RPM drop a lot sometimes while at idle. It misses a ton when colder and not as much when warmed up. Any ideas as to what may have caused this. It makes the exhaust smell very very rich....like burn your eyes sometimes.

One though is bad plug wires because mine have some small flakes of rubber missing from the housings, which I though could be from arcing. Can the coils get frapped just from installing the MS? Also right before I pulled the old ECU it had code 16 "EGR function sensor"......who knows.

Let me know what you think, and the car is bone stock, very well maintained.

You need new plug wires. Unshielded wires that possibly or do arc will cause misfiring.
You also need to clean the ground wires on the engine up by the throttle body.

Is it just idle misfire that you're noticing or any other behavior you're concerned about?

Either way go ahead and replace your plug wires-- if they're old enough that small chunks are falling off of them then that can't be a good thing. Maybe new NGK plugs too.

Have you done any tuning of your VE table yet, especially around idle? Do you have a wideband? If it's leaner than about 13.3-13.5:1 at idle you'll likely get slight misfires... Too lean and they'll be bad.

And that can cause the raw fuel smell even though we're talking about being too lean-- as the misfire itself will spew raw fuel into the exhaust which would be what you were smelling.

If you don't have a wideband tune your idle VE for lowest MAP pressure. adjust the area around where you idle somewhat evenly to help it stay stable (if you need to lower the ve, lower all of the idle areas 1 point at a time, use multi-cell select to make this easy).

sorry but, what is VE?? And also whenever I push in the clutch while driving the RPMs bounce about 800rpm four or five times before smoothing out.

VE is your fuel map.
Have you read the manual yet because VE is a pretty basic part of MS?

Sounds like you've completed the Plug part of Plug-n-Play, now onto the Play part-- that means fine tuning for your car. Then you get to really play. The base map is REALLY close, but each car will vary a little. The manual goes over this several times that fine tuning is very highly recommended. In addition to reading the MSPNP manual I recommend reading the MS1 Extra manual that gets installed with the software CD. It will go into all the basics of what a MegaSquirt is and does and how to get the most out of it. Note it's coming from a DIY perspective of having to build/mod/wire it all up. The MSPNP takes care of all that for you, and 95% of the tuning on an n/a application-- you've just got to fine tune it. A massive amount of work has gone into making your experience as smooth as possible, as much as could be done from here- you've just got to take it that last few yards to the goal line. We will be glad to help from here-- work with our support team, let us know what you're seeing, and we're glad to help. We'll review datalogs, suggest settings, etc. We can't tune your car remotely, but you'd be surprised what we can find in a datalog sometimes.

As for your idle- I may have some settings to try that could improve it a bit. Shoot me an email and I'll send you screenshots of the test settings. It will sometimes oscillate a tiny bit before settling in, but the updated settings that I'm testing seem to be a bit better and more stable than the base map. Once I confirm that for sure I'll release an updated base map.

I have read the manual and do know that I need to tune more, but have not had time to figure it out. I have been spending all of my time ordering parts. I just finished that and will get the car running good before turbo install. Sending email FoundSoul.

Ygm

my MS was doing the same kinda crap last weekend after running fine for months. I traced it down to a bad connection in my switchbox. (if I bypass the switchbox for injector bank 2 the problem goes away). So it's possible that you have a bad connection/wire somewhere as well.

Something to consider.

He probably would have noticed that equally with the stock ECU. He mentioned feeling a miss with the stock ECU, but said it was worst with the MSPNP. We them out on a running car so it's not the MSPNP. The miss with the stock ECU is likely the wires/plugs maybe. The fact that's it's worse with the MSPNP is likely that it's not fine tuned for his car and I bet it's a bit lean...

Yeah, maybe lean but I dont have the wideband in yet so who knows?

At idle, tune for best MAP (lowest kpa which is highest vacuum), that will usually get you pretty close.

When is the wideband going in?

could go in this week, but maybe not until I tear it down for the turbo....

Here is a pic of the plug wires that have unusual flakes missing from the housings:

http://i243.photobucket.com/albums/f...d/IMG_1511.jpg


Attachment 215953

so...
you have misfires
and your plugwires look like that

hmmm
:inout:

I'd definitely replace those, and go ahead with new plugs while you're at it. For a little fun start the car in a garage at night and turn the light out, I bet you can see sparks jumping across the wires ;).

Ohhh, sounds like fun, maybe a movie. I just wanted others to see the problem so they too can fix the problem. My new wires should be here wednesday!

So, I did start the car with the lights off and no sparks??? Today I also installed the new plug wires and I still am getting misfires. Could it be the coils? they are 11.5k and 11.79k Ohms between the output terminals? I really want to solve this issue before the turbo goes on. What else could it be?

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)

As for the clacking sound, without hearing it it's hard to say- is it just when you romp on it? Or???

You want to be careful if you're not sure the tune is spot on-- think about it this way. That tune was spot on on my car, and has been on most other near stock cars. If it was lean enough on your car to be in the 16's at idle then it may be lean everywhere else too- and you may not be doing your motor any favors...

What do your AFR's look like?

The clacking sound is right away when I stomp on it real quick from idle in neutral. Yeah, I put the VE back to stock in that area and just kept the idle tuning.

I am still on the narrow band O2 sensor so I am not sure, but I did send you a few datalogs the other day over email if you could check them out.

I got your datalogs, but they were from before you did a little idle tuning and sorted out the lean miss. Shoot me a short datalog with just this problem in it. Ideally wideband would be helpful-- I may not be able to see mush without it, the narrowband moves around so much, and is often not warm enough at idle to trust at all even for a rough lean/rich.

Ok, the wideband is not going to get here in time before I tear the car apart, tonight, for the turbo system. Therefore I will not have the datalog with wideband for maybe 3 weeks. The injectors wont get run until then either. Check out my build thread in the DIY section if you want to follow wlong in the next few weeks. I will be back to this post when I get the car together. Thanks for all of the help!