michael

iTrader: (1)

Photo album link below.

So had a wonderful surprise on Dec 23rd. Saw a squirrel with a large piece of cardboard walk under our 91 Formy (383 TPIS mini ram) then jump up in the engine bay. Needless to say it has been there a little while and both the pass and driver side by the firewall are trash.

I know there wasn't anything spliced into the pass side but there was on the drivers side. We got the car used so I'm not sure what was what. From what I could get a look at it was too much of a mess to piece what was spliced to what. The extras that I know of that could possibly have been spliced in that area are an a pillar airflow/fuel meter, tach, and shift light. I know the O2 sensors aren't factory but are spliced into the harness lower so those shouldn't be an issue with re splicing into another harness. There was fog light wiring connected around the drivers side firewall but there wasn't any fog lights so I did remove that section of wiring already.

I'm not great when it comes to reading flow charts (thanks add) So I'm leaning toward a painless harness so I know what wires are what for the splicing process.

I do know before the little *** got under the hood that both the a pillar tach and dash tach weren't reading and would sit on 0. This is something that developed after we purchased the car because the dash tach was working properly but the a pillar tach was kinda all over the place.

Does the harness on a formula tie into a block in the pass fenderwell or does it go straight to the computer? The camaro has a block that it ties into on the firewall so i was wondering since there is a ton of splicing done to this car. Some down right at the computer connection with labled tags. Most is done under the steering wheel. Don't get me started on that electronics nightmare.

There have been several things we have wanted to pull out of the car just to cut down on the electronic mess ( air ride rear shocks with compressor, the shift light and tach on the a pillar, and line lock since we have no inclination to take it to the strip. This should cut back on some of the mess under the dash.

Car has electric cutouts also but they seem to not be connected. I'm sure the wiring for them is under the dash also but has just come unhooked or a fuse has blown or something. There is an overhead console light that I think kept draining the battery because if the light was turned off it would be funky with actually turning back off. So I think it was draining the battery. It has an alarm but a car alarm shouldn't drain a full battery in a weeks time to where you get no reaction with the turn of a key.

Just looking for anyone with experience in a 383 and staying fuel injected I guess and what you had to splice into so I hopefully can figure out what to do.

Does the 91-92 firebird and camaro use the same hvac wiring since it got that on the pass side also?

I've attached the (unfortunately) only two pictures I had of the drivers side wiring. Not really enough to trace things back for a new harness if you ask me. :-( I also attached the mess under the steering wheel. Yea us!

I also should add it was a factory T5 but has a T-56 now.

Photo Album

Drew

iTrader: (58)

The Camaro harness is probably a lot closer than you think. The only real difference between the two is the battery location, and subsequently the location of the charcoal can.

There are three harnesses under the hood. The ECM harness wraps around the engine from the passenger's side of the cowl all the way to the driver's side. It plugs into the firewall at C100 along with the headlight harness. The HVAC is it's own harness.

Personally I'd pull all the aftermarket components that won't be used and get them out of the way. Figure out what's going to be reinstalled, and find wiring diagrams for those items. Once the original harness, or a replacement is back to square 1, you can reinstall the add-ons as needed.

Any aftermarket harness is going to require more work than an OE harness. Get a GM/Helm service manual for your exact car and read the electrical section a few times. Study the diagrams until it makes sense and you'll have a better idea of what's there. Then (if it were me) I'd either fix what's there, or get a donor harness from approximately the same year and model car, and swap over. Camaro Vs Firebird, auto vs manual, won't account for as much difference as model year. Even the V6 harness is fairly close since they used the same ECM as the V8.

michael

iTrader: (1)

Aren't the painless harness's already pinned out with all connections though? I don't see how that would be any more work just put in place and connect like a factory harness. The only difference is it's not OEM and the wires are labeled correct?

I know the hvac and headlight harness are their own harness. The harness that comes out of the passenger fender is chewed up along with the main line that runs toward the back of the engine including some of the hvac harness that is on the pass firewall area. :-( I didn't get a ton of time to look at it for 1. being completely pissed off and 2. having to leave for Christmas. I really only had time to glance at the damage and remove the nesting material that was packed in between the hvac box and backside of the wheel hump.

Are there steel braided looms that will fit over wiring? I know they make them for hoses for dress up but damn this is the second car they got. Years ago they got my 91 camaro and it's still sitting. Not as much of a concern since the heads really need to be redone on it and it needs a right rear quarter panel and tail light bar replaced. The bird on the other hand has to go back together. Still paying on it and I purchased it from the guy where my fiance and I met. So there is substantial history involved with this car.

Drew

iTrader: (58)

Painless harnesses are "universal". If you're putting a TPI in a street rod maybe they make more sense than trying to adapt an OE harness. On the other hand, an OE harness fits the OE application like a glove because it's custom built for that application. That's without getting into all the little things integrated into the stock harness that won't be in a Painless harness since the aftermarket harness is only intended to run the EFI.

Sounds like you need a dog, or a cat, or a garage, or something.

michael

iTrader: (1)

I think that depends on the model Painless harness that is purchased. It seems the 60103 is specific to TPI and Map cars (Camaro, Firebird, Corvette)

Year: 1990 - 1992
Make: General Motors
Model: Camaro, Firebird, Corvette
Engine: 5.0L, 5.7L Tuned Port Injection w/ Manifold Absolute Pressure Sensor (MAP)
Trans.: 200-4R, 700-R4 and Other Non-Electronic

It also explicitly states the SD ecu as one of the required computers for this specific harness. 7730

"This harness also requires the following mating parts; ECM #1227730, #16198262, or #88999196. The EPROM broadcast code must match tire diameter, gear ratio, engine size, and transmission."

Maybe I'm incorrect in my assumption based off the information Painless gives on their product page but to me this harness is specifically designed for the L98 with MAP (SD) sensor. They also list one for the MAF (Non SD) version.

Drew

iTrader: (58)

You're not wrong, you're just reading it wrong. It's specific to SD TPI, but not to a specific car. It's a universal harness intended for the engine swap market. That's why all the components to run the emissions equipment, etc are add-ons.



Aside from all of that, even with the current rebate as advertised on Summit, a painless harness will cost you twice as much as a good used harness that will be much closer to dropping in and fitting the way it should.

michael

iTrader: (1)

I get what your saying with that now. Odd Painless doesn't advertise the harness as such though. They make it sound as though it is geared for direct fit to an f-body or vette. Seems a factory take off will be the better bet.