For example, GE9, which is the EGR Solenoid...both V8 and V6 are the same, although, they are
different colors. GF4 is the Air Diverter Valve, so I'll have to run new wires to that thing on that pin? BD13, for the power steering input, V8 version said it's not needed. So, the V8 car doesn't need it??? GF4 and GF5 were the EGR Solonoid controls #2 and #3 for the V6...V8, what do I do w/ those wires? It has to use the same Electronic EGR as my 6 did...unless it's different? Thank you for the chart, and for any info you can give me in clearing this stuff up. Also, what extra wires, if any, are needed for the V8 swap? I know I'll have to splice in 2 more injectors on the fuel rail, but anything else?

Thanks in advance!!

 

Any help on this one?

 

Sorry, the only help I can offer is for you to get the manual for your year...it'll have V6 and V8 stuff you need.

Pricy, but invaluable.

www.helminc.com..or try a search on ebay, etc.

 

The spreadsheet that I gave you has what the V8 needs (left-sdie) and what the V6 can offer (right-side). If the V8 (leftside) needs something that the V6 doesn't have, then you must wire up an alternative either by splicing off the V6 wire that I listed or running a complete new wire. I personally prefer splicing off the available wire.

As for your EGR, it will depend on the manifold you are using. If it's a TPI type base manifold, then you will need the appropriate EGR for the V8 - you can't use the V6 (other than splice off the appropriate lead). Remember, once you install the V8 memcal, the ECM will behave as for a V8 - NOT a V6 anymore.

As for your specific wiring questions:

GE9 - Just reuse it. You will most likely need a new connector, but you can reuse the actual wire by splicing it into the appropriate V8 connector for the EGR.

BD13 - Ignore it. The V8 doesn't use a Power Steering switch in it's programming.

GF4 - The V8 needs the air diverter. As with GE9, you just reuse the wire by splicing the V6 wire it into the appropriate connector for the air diverter on the V8.

GF5 - Ignore it. The V8 doesn't use this lead.

Yes, you can splice an extra injector lead to each bank so you have 4 injector leads on each side. The system is "batch fired" and the injectors used on our cars are "high impedence" and use very low current draws. The injector drivers are identical on the V6 and V8. Just splice an extra injector lead to each side.

Lastly, make sure you wire the tranny right. If it's an auto, then the lead (GF6) works the same. If it's a manual, you must rewire GF6 to become GF1 (the V6 AC Comp relay is not used). Just pull the "GF6 pin" from the Green Connector (that's what the "G" means in GE or GF) and switch it for GF1.

Get the proper tool that I provided for a link in the e-mail I sent you. It also has a "weather pack" tool, which can help to swap the wire to the proper weather pack connector.

Just go to a wrecking yard and buy a "practice harness" with connectors. Practice on that before attempting to swap wires/pins/weather packs on your original harness. If you do it right, you can make your harness look and work as if it always was a V8 harness.

Good luck

 

Thanks a lot Glenn...I really appreciate your help. Sounds pretty easy to convert the harness'. I think I'll take on the challenge. I'll keep you guys posted on the outcome!!

Adam

 

Would a swap from 2.8L V6 MAF (1987) to V8 TPI MAF be possible to do using the v6 harness? I mean are alot of the wires common as it appears the SD harnesses are? I have a fairly clean 87 hardtop body that was a v6, and my 89 Formula 350 that's getting ragged inside (t-tops ) and outside (must have a "Hit Me" sign on it!). And I've thought of swapping over many times. The thought of rewiring and not knowing how much harness needs to be swapped from one car to the other has kept me from it. Should I just sale the v6 body and try to find a 305 tpi car instead?

 

I know the SD V6 to SD V8 works because I have an actual GM factory shop manual for 1991 Firebirds and I was able to correlate the two "pin-outs".

I know the "pin-outs" for the 165 MAF (1989 $6E version which doesn't use the cold start). But I have nothing on the 1987 2.8 MAF V6. If you can get a copy of the "pin-outs" for the ECM connectors for the 1987 V6 MAF, then I can tell you how close it is and what modifications you'd need to make it work.

Talk with Vader about getting a copy of the 1987 V6 MAF pin-outs. That guy seems to get his hands on everything.