Ecm Bad, Interchangable?

[madmaxman1986]

Hello everybody, I'm new but I promise I'm not a "hi-bye"!

I just bought a 92 sc300 and 5 miles down the road the dash lit up.

Check engine, oil temp and oil pressure lights.

There's tons of white smoke (it's not the head gasket, no coolant loss and good compression) and it smells like raw gas. Tons of gas in my oil. I trailed it home.

It's not the valve stem seals, there is no oil loss either.

200k on the clock, but it feels like it would run great if it wasn't DUMPING fuel.

I'm almost positive it's the ECM. It has water damage, and the FPR has no fuel in the vacuum line, so the diaphram is ok.

I'm really just asking to confirm my thoughts, to see if anyone else has had a similar problem or if somebody has an ECM they could sell me.

My part number is 89661-24310. Auto with traction control. 1992.

I've been told the're NOT interchangable, but I've read 92-94 are if they have identical options. (california, auto, traction control)

Thanks for any advice, I do appreciate taking the time to respond.

I'd like to drive the old girl, my 5-spd 944 kinda sucks in morning traffic!

-cale

Minneapolis

[Graham]

Hello everybody, I'm new but I promise I'm not a "hi-bye"!

I just bought a 92 sc300 and 5 miles down the road the dash lit up.

Check engine, oil temp and oil pressure lights.

There's tons of white smoke (it's not the head gasket, no coolant loss and good compression) and it smells like raw gas. Tons of gas in my oil. I trailed it home.

It's not the valve stem seals, there is no oil loss either.

200k on the clock, but it feels like it would run great if it wasn't DUMPING fuel.

I'm almost positive it's the ECM. It has water damage, and the FPR has no fuel in the vacuum line, so the diaphram is ok.

I'm really just asking to confirm my thoughts, to see if anyone else has had a similar problem or if somebody has an ECM they could sell me.

My part number is 89661-24310. Auto with traction control. 1992.

I've been told the're NOT interchangable, but I've read 92-94 are if they have identical options. (california, auto, traction control)

Thanks for any advice, I do appreciate taking the time to respond.

I'd like to drive the old girl, my 5-spd 944 kinda sucks in morning traffic!

-cale

Minneapolis

Welcome Cale,

Sounds like you have quite a problem there... must be a 'Katrina car if you have water in the ECM.

A couple things come to mind that might help get you started:

1) If you do a search of the forums here, you can download the SC400 factory manual as a PDF.

2) You can set up the SC in "report error mode," search the forums for that. A single jumper wire saves needing the OBD-I scanner (not the OBD-II).

3) Maybe the injectors are being told to turn on at the wrong time by the ECM: ebay yourself a new ECM and swap it in. Might be the miracle you're looking for.

4) Or maybe there is a hardware problem, like valves/seals, etc. If gasoline is in the oil? It means gasoline is ending up on top of the heads. So how did it get here? Leaking injectors or injectors being told to fire at the wrong time, or valve/seals leaking. Then the gasoline leaks down into the oilpan from the top of the heads via the oil return ducting. What is strange is you report gasoline is in the oil, but you have 100% good compression across all 8 cylinders? If so, you need a professional shop to inspect the motor, especially the heads. It is possible that the intake valves are not seating or the seals are leaking out the gasoline mixture during the compression stroke. One of your cylinders would probably show low compression with this though.

The Good News: there's no way you bent the valves / ruined the heads yet. The 92-94 have the 1st revision V8, which is not a interference engine, but this changes around 95-97 (e.g. the VVti's are interference after this). You can search the forums for this too.

Good luck!

-Graham

94 SC400 / 290k miles