Tom. M

We are working on a 83US 928 that has been retrofitted with a 84 Euro engine. We didn't do the install work, but are trying to track down a non start issue. Seems the injectors are not opening. Car will run with a shot of ether so it's just the fuel issue (It has good fuel pressure btw).

We are trying to decipher the way the brains were wired into the Stock 83 US fuse panel. Since the manuals don't cover the Euro cars very well, it's difficult to track down the wiring schematics on the Euro LH brain.

Is the 84 Euro LH brain the same as a US 85 LH brain? or does some one have the wiring schematics for the 84 Euro brain?

TIA....

Lizard928

Tom,
The wiring for the brains is the same between 85US and 84 ROW. That is to say the pinouts are the same.
But the 84 euro will have no O2 sensor, whereas the 85 will.

Make sure that the LH is getting power first.

hacker-pschorr

Did the car ever run with the LH brain?


In order for the LH to fire the injectors, it must receive a crank signal from the ignition amplfiers. Where are those located? They would not have been part of the stock 83 ignition so they must have been retrofitted somewhere.....

Tom. M

Thanks Colin...that is what Ken suspected and we'll go from there.
Hacker..yes the car ran great, but after it sits a while it seems to go into this no start mode. We are suspecting some bad connections, but need to see what goes where before we can trace it effectively.


thanks for the tips..

BTW..the whole euro harness and stuff was transferred (including ign amplifiers up front near the nose of the car). They just spliced the euro brains into the existing panel somehow.

PorKen

Does it have the proper (LH, high impedence) injectors?

hacker-pschorr

I've wondered how long it would take to fry an LH brain using the L-Jet injectors.

Tom. M

Yep, it's all euro.... engine wise...someone just shoved the euro harness through the firewall...and connected it up.
It ran great back when it first was put together...and Thurston did some troubleshooting when it quit..said something about overloaded connections..fixed that..and then it ran for a while..sat..and then quit running..

hacker-pschorr

I would jumper the fuel pump relay, and then try to start the car.

If it starts, the relay is bad or crank sensor signal to the LH is having issues.

If the relay checks out, I would trace the signal wire from the ignition amplifiers to the LH, see how they spliced that together or where it's routed.

Do you have a spare LH to try from a US 85/86? I tested my 85 EuroS LH in a friends 86.5, ran perfect.

John Speake

The Euro 84-86 LH are very reliable. If you jump the FPR be very careful to get the correct pins as it is easy to blow up the FPR driver stage in the LH.

Try jumping LH relay next, same caution required....

Tom. M

Thanks guys.. I'll pass those tips along to our electronics expert .