Cenco Fbody

So I made the mistake of buying a used motor (LT1, 94) off of a guy, and was under the impression it was stock. We threw it in my 95 Z28 a4 and much to my surprise it didnt run. Barely idled, wouldnt even push the power steering, almost no vacuum. Fast forward 6 months to now, car still in my driveway.

New info surfaced that suggests the 94 motor has a fairly extreme cam in it, and was in a m6 before. I had just come to accept that the problem was a major conflict with the Optispark from the 94 not "taking" to the 95 car, and was planning on pulling the 94 shortblock and throwing the 95 topend on it.

My question to you gentlemen is, could the problem with the motor not working be due to the fact that the 95 ECU isnt tuned at all to work with this supposed huge cam?

streetwarrior96

thats a big 10-4

daniel6718

iTrader: (36)

yes...and you dont need to change shortblock or anything

the motor a 94 cars a 95...get a 94 harness and the opti will work with the same computer...if not keep your harness and switch the timing cover/distributor from your old motor or a 95 motor...

now you bought this motor and it has a cam in it? do you not want a cam, i have a stocker i can sell ya cheap with springs! or trade! does it have any other goodies inside like rockers guideplates springs?

Fastbird93

iTrader: (10)

The car wouldn't even fire with a opti harness mismatch. The plug for the vented opti's is about twice as long as the plug for the non-vented opti's.

The opti isn't going to be the issue there. Sounds like you got a longblock for longblock swap with opti's, so I'd look elsewhere.

Do you have any info on the cam that's in the motor??? FWIW, with an "extreme" cam as you put it, you're going to see MUCH less vacuum at idle translating into a lower MAP signal, and a host of issues derived from that. If the car is trying to run on a bone stock tune, your closed TPS spark advance is probably way too low not to mention your VE tables will be too rich for the idle conditions, and the biggest thing is that your idle speed probably needs to be bumped up quite a bit from the stock ~750 area.

Get a tune and see what happens. Unfortunately, that may mean pulling the cam to pull the part number/grind number off of it to identify.

slowmofo

iTrader: (6)

How Extreme is this cam? My 94 with a 847 ran fine on the stock program. Runs alot better with a tune, but did run well enough to drive around and such.

Cenco Fbody

I considered the Opti harness issue earlier when the car first had the motor swapped in, but ultimately I didnt do it because it seemed like it wouldnt run at all. But I would def be willing to try anythnig at this point, I need to get the car out of the driveway finally.

The reason I was going to swap the shortblock now is so I could throw the good 95 topend (still have the original motor) on the good 94 shortblock (the 95 shortblock has some toasted bearings somewhere in it).

I have no idea how "extreme" the cam is, I was under the impression from the seller that it was a stock cam, then my dad mentioned on Father's Day that when my family member had picked it up off the guy the guy had mentioned a cam...just now. I wish I had known this info back in August whne the motor went in. When he said that I thought of the tune, since it seems like these cars can be fairly sensitive to cam swaps.

So I guess I have some things to look into at least, thanks guys youve given me some good info to go off!

Cenco Fbody

I dont know anything (literally) about what cam
it would be, or anything related. I thought it was a stock motor. But if it turns out I need a stocker I'll hit you up for sure!