I think I bought a new distributor to fast. I didnīt check what Iīd need I bought an MSD 85551, but the car is a -88 TransAm. The stock distributor was FUBAR.

The problem is that I donīt get any injector pulses. Everything is in the stock module? There should be SOME way to fix this. Iīm also hooking up an MSD 6AL.

Please, tell me itīll work out.

 

The dist. doesnt effect the injectors at all... sounds like you got a whole nother problem... I dont know..

 

The distrib you bought is a mechanical-advance unit that contains no HEI module. http://www.msdignition.com/

With no HEI reference pulse to the ECM, the computer will never know that the engine is running - which turns off all the fuel and timing controls.

To make that distrib work you need to lock out the mechanical advance and connect the mag pick-up to the GM HEI module.

There should be instructions for both things on the MSD site (somewhere).

 

Hmm, ok. But stock is not a HEI distributor. It has an external coil, or have I missunderstood what HEI is?

 

Yes!
I made it. I only had to connect the tach output from 6AL to the purple/white wire on the connector that went into the distributor.

Now I only have to take care of the vacuum hoses thatīs not connected, and then my HSR is complete!!

 

Understood you were working on an 88 TA. Stock distrib there would be HEI with computer control of the spark timing, as far as I know. For ECM control of spark, GM used a 7 or 8 -pin HEI module to send/receive signals to the ECM. If you are not using ECM to control spark timing, ignore previous comment about locking-out mechanical advance.

The purple/white wire is the distrib reference signal to the ECM. In the GM design, I believe they use an open-collector switch in the HEI to ground a ~5v ref signal through a pull-up resistor in the ECM. If you are using the MSD tach signal for a reference pulse, you should probably look here to see where the MSD signal comes from: ftp://ftp.diy-efi.org/pub/diy_efi/do...s/msd6a_02.pdf (although I think that site is down today)

I don't remember exactly, but I thought the MSD signal grounds a 12v source. If so, you are possibly feeding some extra current back into the ECM reference voltage source. Dunno what that does to the ECM long-term.