IT's runnimg but running like crap:HELP!

[john_V63400]

OK my car sounds great but runs like poop. When I start th car and rev it up, it dies after I let the gas off.

Im wondering if I have to teach the PCM how to handle the cam. Does any one know what I can do to help it run smoother.

[AaronGTR]

You're probably still running too rich. Mine did that when I first swapped injectors. I had to keep my foot on the throttle to keep it running. It's really hard to say though without knowing your A/F ratio. Do you have a wideband O2? If not are you doing any scanning and what are your O2 sensor values? You might have to keep removing a bit of fuel in the injector flow (IFR) table until it will stay running and then fine tune it with the MAF table. Raising the idle speed might help with the cam also.

[john_V63400]

RSM deleted my MAF so I dont have one. I fixed the problem I think, I just bumped the idle up to 1300 rpms, and now it doesnt die when i let off the throttle. I noticed the more I drove the car the better it ran. Its running pretty good right now, a little rich at times but I think I got it. Now my TCC silinoid went out so Im changing that.

I think with that cam I just needed to set the idle a little higher.

[IsaacHayes]

1300 rpm is high even for a decently hot cam.

If you could some how edit the PCM to put the MAF tables/etc back in, I think that tuning would be way more easier. A MAF will help the computer know how much air is coming in, important for boost. Unless the air exceeds the MAF range, but with only 8psi I dont think thats an issue. Just add extra maf tables probably. Other will probably chime in, but I think I'm right for the most part...

[tejohnson]

Please don't run without a MAF. Just because the folks at RSM are, well...

...stupid does not mean you have to be. Think about it. You have a 1-bar MAP, no MAF, and running boost. Plain and simple, that is the most retarded thing you can possibly do. (Yes, I feel strongly about this).

You should put the MAF back in, raise the table, considerably in the higer Hz range, and up about 5% in the lower Hz range. Then you should be able to drop your idle down to 850-900 without any issues... Running in Speed Density mode on a untuned OBDII PCM is a good way to:

-Pop a piston
-Destroy your 45e


EDIT: And BTW, the stock MAF is good up to *at least* 12-13 PSI

[IsaacHayes]

How would it destroy the trans?
I have speed density from the factory. No maf on my 3100. Of course I'm untuneable bastard odb1.5 too. Probably one of the most unfriendly setups as far as tuning options.

[tejohnson]

And your PCM is set up to run without a MAF from the factory. The OBDII PCM's are not.

Part of the shifting of a 45e is based on the MAF values. Perhaps that is why his Torque Converter Clutch solenoid took a dive...

EDIT: To quantify this, do some research on how the MAF and TPS values work within the PCM. MAF is monitored to also check sanity of TPS values to watch for a bad TPS. (i.e.: unmetered air in the form of a vacuum leak, engine load, etc.) This has an effect on not only the shifting, but TCC apply and release.

[IsaacHayes]

right, I was just throwing it out there. Yeah, I'd be putting the MAF back in ASAP if I were him.

[Azrael]

I think RSM deleted the MAF due to problems caused by the BOV. Just throwing it back in there might help to solve the current issues but it could also cause a few more. I don't know the specifics about this though.

[tejohnson]

How does a BOV cause problems with a MAF? The only issue I could see is any form of recirculation back to post MAF which would possibly be unmetered air into the plenum.

[IsaacHayes]

Re-route the BOV to dump to the atomesphere then or further away from the TB.

[Chopperheadinc2005]

Running rough after you give it gas

i reset the timing on a 92 3.4 and it is running but when i give it gas it starts running rough. any ideas?

[AaronGTR]

How does a BOV cause problems with a MAF? The only issue I could see is any form of recirculation back to post MAF which would possibly be unmetered air into the plenum.

The problem is with RSM's setup. They have an elbow going straight from the SC outlet to the throttle body and the BOV is there. So if the MAF was in front of the SC, when the BOV opens it would be letting out air that has been metered and throw off the fueling. If he added the MAF back into the system before the TB and after the BOV like you are using on your turbo setup then it would run correctly. (germ and I had a big argument about that before remember?) I remember someone with the RSM setup has done that while re-routing the piping to add an intercooler and he said it ran much better. SHould go like this... intake-->supercharger-->outlet-->BOV-->MAF-->throttle body.


FYI for those that might not have seen, it was recently revealed that the "tuned" pcm RSM gave with the kit was nothing more than a stock program. Nothing changed for the MAF at all. The cars just ran in speed density mode which is why they run so crappy at first until the fuel trims have time to adjust and thats also why the trans shifts funny as Todd has already explained. I would definitely moddify that kit to put a MAF back in and I'd add an intercooler too if the money is available. I also agree 1300 rpm is way too high for an idle. You should be able to get it to idle properly in the 800rpm range.

[IsaacHayes]

Wow, so do they use a RRFPR then to add more fuel when it's in boost? They just disable the MAF, or do they just turn off the DTC? (later would be better as you could just put back in the MAF and not edit the ECM).

[sprucegagt]

They disable the MAF buy simply unplugging it. Then turning off the DTC in the computer to prevent a check engine light. That's the extent of your computer tuning from RSM. This is really a VERY poor way of making this kit work. 1 Bar map sensor used with a $4 K supercharger kit, probably one of the dumbest things you can do. No wonder this kit has always under performed.