spare ECM

[JD1964]

I'll be looking at a 1994 Fleetwood LT1 for possible spare parts in the near future. Is the ECU in this car worth getting as a spare? How would it compare to the ECU in the late 1994 Z28 application?

Anything else I should grab? I was thinking maybe the fuel rail if it gives me different options for fuel line connection and routing compared to the Z28 rail.

Anything else?

Thanks

[LeMarky Dissod]

A spare pcm is always a good idea, even if there is no meaningful or functional difference between this 16188051, that 16188051, and any other 16188051.
steveo's OBD1 LT1 .bin file collection probably already has that Fleetwood's .bin file - but just in case, read it out and save it before you use it as your spare pcm.

[In-Tech]

I'm still trying to buy a 94/95 lt1 pcm for bench testing. I forgot about the roadmaster, impala, caprice and fleetwoods having them. Do you guys have a diagram where the pcm is located in the oddball cars. Of course I know where they are in the camaro/firebird but no clue on the rest.

[NomakeWan]

The only difference between LT1 PCMs I am aware of is the physical knock module inserted into it (it’s matched to the car), and that the Corvette ones have some fancy OBDII-related hardware that isn’t actually necessary. So go nuts!

[sherlock9c1]

I'm still trying to buy a 94/95 lt1 pcm for bench testing. I forgot about the roadmaster, impala, caprice and fleetwoods having them. Do you guys have a diagram where the pcm is located in the oddball cars. Of course I know where they are in the camaro/firebird but no clue on the rest.

The B and D body PCMs are located in the front drivers' side corner just beneath the air filter box. Very easy to get to.

[JD1964]

Thanks for confirming. I'll surely make an effort to acquire at least one spare.

I have two Foxbody Mustangs that use A9L and A9P PCM's. They have this condition where the capacitors leak and cause corrosion on the circuit board. I've had both of them repaired and also have a spare.

Do these GM LT1 PCM's have any weak points that are known to fail? If so are they serviceable?

[LeMarky Dissod]

The only difference between LT1 PCMs I am aware of is the physical knock module inserted into it (it’s matched to the car), and that the Corvette ones have some fancy OBD2-related hardware that isn’t actually necessary.
So go nuts!

Whatever the hardware differences between 16181333 (Y-car LT1 pcm) and 16188051 (F- D- B-car LT1 / L99 pcm), none are operationally meaningful or useful to us.

[steveo]

Do these GM LT1 PCM's have any weak points that are known to fail? If so are they serviceable?

they're bulletproof. you almost never see a dead gm ecm from the mid 90s.

i had a dead one once that was due to only one really loose ground being connected and run like that for hours

there was a mexican guy on here not too long ago that had major moisture intrusion issues

i've seen the fan driver die before, only once that i can remember

basically you really have to try to kill it

it used to be possible to brick them during reflashing but with flashhack now i doubt you'll even need a spare

yes they're serviceable but not very well documented

[JD1964]

Here with Fleetwood. Got the pcm out already. What else should o snag ad spare?CA614E88-CCC3-4285-9E3C-1199AE9107C1.jpg

[JD1964]

I took the PCM, the temp sensor in the water pump, the low oil level sensor, the upper radiator hose, ignition wires, optispark vacuum lines and oil dipstick. $51 for all that.

Interestingly, the 94 Fleetwoods had vented opti as this one did. I went for the opti and the timing cover initially but did not have a hub puller with me. I had planned to go back but I've just decided to modify my 94 Camaro opti to vented instead of doing the entire component swap.

[LeMarky Dissod]

… the 94 Fleetwoods had vented opti as this one did. I went for the opti and the timing cover initially but did not have a hub puller with me.
I had planned to go back but I've just decided to modify my 94 Camaro opti to vented instead of doing the entire component swap.

ALL 5- & 4- door / IronHead Opti-Sparks have been actively vented with a Vent & Vacuum Harness from the inception of the IronHead / 5- & 4-door LT1 variant in 1994.

Why GM waited until '95 to update the 2-door / AluminumHead LT1 with active external venting, we may never know.
Either way, tens of thousands of parts counters will continue to erroneously insist that '94 Opti-Sparks are passively vented.
Luckily it's not hard to add active venting to every Opti-Spark.

[JD1964]

I could not resist going back and getting that OEM vented opti on the 94 Fleetwood. It's home now with the matching cam gear and timing cover. Took it apart and it's very clean inside with no signs of moisture intrusion and has the OEM Mitusbishi sensor. The car it came out of had some serious front end collision damage, even for a big Caddy. So, It's obvious what took this car off the road, not the opti. All three parts came to $72. I'm very happy with this.

I learned there are other ways to snag the now discontinued and preffered Mitusbishi sensors. See thread link below

Good info on stocking good opti sensors at this thread over at Corvette Forum



https://www.corvetteforum.com/forums...optispark.html

[yoheer]

So how to find spare mitsubishi sensor for opti? what parts should I search for? For dodge stealth/3000gt for example

[JD1964]

So how to find spare mitsubishi sensor for opti? what parts should I search for? For dodge stealth/3000gt for example

I looked and cant confirm anything, sorry. I have been using Rock Auto and the images they have to try and match what out opti sensors look like and compare to those of other cars. Maybe the actual sensor with in the sensor housing is the same on some but I don't know for sure. I have not yet found an image of a complete sensor unit that looks the same as ours. I'm not saying it does not exist, only that I have not confirmed it as of yet.

Perhaps the info at the link I posted is not accurate......maybe....

But if I knew other vehicles these sensors came in from the factory, they would be on my hunt list for sure.

[beasleyrb]

I'm glad you found your parts. It would have been hard for me not to take the whole engine. Maybe could have gotten the throttle body too?? and he MAF sensor??