Injector/rich condition help

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Aug 4, 2005 | 10:52 PM

nitrocharger

Thread Starter

Racer

Joined: Sep 2002

Posts: 378

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From: Raleigh NC

Injector/rich condition help

I have been fighting a rich burn condition on my TPI ever since I converted it over (its a C3). The TPI apparently is out of a 88 Trans Am and I have no idea what size injectors it has. The engine runs very rich and the computer can never seem to correct itself, although I have seen a few isolated cases where it actually works. All the sensors have been tested and/or replaced and the engine is a ZZ2 crate engine. The last thing I can think about trying is putting new injectors in as perhaps the injectors are clogged thus preventing the fuel from atomizing? Any help is appreciated!
PS, I have turned the fuel pressure down to 32 PSI

Aug 5, 2005 | 04:51 AM

Morley

Drifting

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From: GA

Well, you really need to know what size injectors you have in there AND, open the little cover on the ECM and look at the silver tag on the prom chip on the memcal, You'll have to take the memcal out and remove the blue plastic cover, what is the 3 or 4 letter code on the silver sticker?

Aug 5, 2005 | 02:17 PM

DOCTOR J

Burning Brakes

Joined: May 1999

Posts: 760

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From: Greenwich, CT

Quote:

Originally Posted by nitrocharger

Any help is appreciated!

Seems like you may need to recap the basics:

Do you have datalog readings from the ALDL port?

Are all the sensor signals in range? In particular the TPS, CTS, MAF, O2, RPM and
VSS signals?

All the wiring, connectors and grounds checked for continuity? Check the intake for
vacuum leaks?

I didn't notice what you have for a trans - is the VSS output from the trans compatible
with the ECM (in terms of ppm)?

Checked for leaking injectors/fuel press regulator? Adequate size on the fuel return
line?

Could be lots of things on a conversion - solving the riddle needs a little more info on
what's already been looked at. Fella here recently posted quite a bit of detail on a
TPI project. Might be worth reviewing his experiences:
http://www.edgesz28.com/edgesZ28/sub...urban-home.htm

Good luck.

Aug 6, 2005 | 11:25 AM

nitrocharger

Thread Starter

Racer

Joined: Sep 2002

Posts: 378

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From: Raleigh NC

The car has a 5 spd Tremec so the VSS is not hooked up. I did a leak down test and the pressure drops to 0 in about 30 minutes. I was told it should take several hours for pressure to drop?

Aug 7, 2005 | 09:19 PM

nitrocharger

Thread Starter

Racer

Joined: Sep 2002

Posts: 378

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From: Raleigh NC

Ok the PROM ID is 2341. I hooked up the ECM to a scanner and at idle the injector pulsewidth is 1.2 ms and the MAF is reading 9 grams/sec of air. Does anything sound abnormal here?

Aug 8, 2005 | 02:31 AM

Morley

Drifting

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From: GA

Quote:

Originally Posted by nitrocharger

Ok the PROM ID is 2341. I hooked up the ECM to a scanner and at idle the injector pulsewidth is 1.2 ms and the MAF is reading 9 grams/sec of air. Does anything sound abnormal here?

We need BLM's and O2 voltages to start.
The PROM ID you gave isn't the one I'm looking for, it should be a 3 or 4 Letter code, not number, you can't get it off the scanner, you need to get it off the silver sticker on the chip.

Aug 8, 2005 | 05:57 PM

nitrocharger

Thread Starter

Racer

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From: Raleigh NC

Akfr
2188

Aug 8, 2005 | 08:25 PM

Morley

Drifting

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From: GA

AKFR=1988 F body with a 5.0L (305)
So, if you have 22# injectors for a 350 in there, the PROM is programmed for 19#...you are dumping waaayyy too much gas in the engine.
You need to either get the calpack for a 1988 5.7L or get 19# injectors OR, get a chip burned for whatever size injectors you do have.
Can you get a part # off any of the injectors?

Last edited by Morley; Aug 8, 2005 at 08:28 PM.