CWerner

I've got a ZZ4 400 hp motor with at TPI miniram tied to an OBD1, Installed 8 yrs ago. It's always run rich and burnt oil. I took it to a local shop and they told me my tune is all wrong, but they can't tune it. The tune is way too rich causing the oil burn.

With no local tuners, what's my best "mail order" solution?

1964 C2 convertible tied to a 700R4 trany. Shorty headers, with no WB O2 sensor. 1997 Camaro ECU

DanielRicany

Well first, confirm that the engine is running rich. Look at BLM on a scanner and report back with your findings. You'll have to let it run for about 10 minutes to get the BLMs to register.

WW7

I agree with Daniel, first you need to verify your running rich with a scanner..If your motor has been running very rich for 8 years the excess fuel could have washed the cylinders down enough to damage the cylinder walls and rings..If it's burning oil this could be a possibility......Lets hope not....WW

CWerner

We did a compression test and it looked fine. After that they pulled the plugs and that's what told them it was running rich, besides the sniff test on your clothes when you drive the car.

I'll update more once the shop gets more info.

bjankuski

Please confirm the ECU, you say OBD1 but list a 1997 computer which is OBD2, do you mean 1987 computer?

CWerner

My memory sucks. It was an ECU for a TPI. The year or so prior to the LT1 motor on the vette. Was that 87?

Cliff Harris

LT1 started in 1992.

CWerner

My memory is now telling me it's an 89 ECU

Anyway, no BLM readings. I had to punt on the work at this time.

Cliff Harris

The 1227165 ECM was used from 1986 through 1989.

WVZR-1

ECM even if after-market should be identifiable by a label OR a scan of the ECM should ID the PROM by the original scan ID even if it were only the "base" ID of the OE. I've not scanned an ECM for a PROM ID for many years but best I recall a Tech1 always reverted to the base even if it were a modified done on an OE core. The PROM might even have the original label in the window of the cover or notes from the tuner who did it.

Mail order isn't what it once was, I'd search for a recommended local with references. If it was done on a correct V8 PROM the cores are worth thieving to some, need to be very careful.

If the ECM is an aluminum sheet construction it's earlier '86 - '89 and if it's a drawn housing with a multi-bolt PROM cover with large square electrical connectors then it's '90 & '91 product if it's Corvette donor if an F-body donor things can change.

steven mack

Just got off the phone with J&M corvettes.I was going to buy a used Mini Ram and I remember them telling me the back four runners run richer than the front.The mechanic said on the LT1 motors That the computer had different fueling programmed for the front and back cylinders. You need a fuel injection system that would allow for this.