Quote from gotmymojoworkin on September 26, 2020, 11:06 am

Hi All - thanks for all the education you provide on your forum. At 50+ my mechanic hobbyist career has just begun but am trying and am willing to learn. Though this might be a long thread, I respect your time and will try to keep it relevant to my skill level, what's been done, possible next steps, etc.

In April, I got a '68 Camaro with a 5.3 (LM7), Tremec Magnum F-Body (6-speed MT) and FiTech LS 70050 system. Very meticulous build with a few minor issues the seller (not the builder) agreed to correct before purchase - most notably, trouble shifting into 3rd. I know the seller removed the transmission and sent it out to a transmission shop.

I took the car out only a few times without any issues (except some tire rubbing in the rear fender). Then one hot Sunday afternoon, I took my wife to lunch. On the ~45-minute drive we ran the A/C full blast but were still warm, but the car ran great. Stopped and fueled up (tippy top) next door to the restaurant, then drove <25 yards to the restaurant parking lot, backed into a parking spot and set the parking brake. No issues up to this point.

After lunch we got in and it started right up. I started to pull forward but it hesitated (and sputtered a bit). I noticed the parking brake was on, so I released it and started off again. The engine continued to sputter and would not accelerate. (Much later I realized that the Coil/Inj D fuse had blown and car was running rich.) I had it towed back to the house and the diagnosing began.

Suspecting bad gas or that I had overfilled, I siphoned several gallons from the tank and donated most to my truck (which was nearly empty) and my lawn mower. Each ran beautifully.

Next, I contacted FiTech Support - who were very helpful. The handheld was showing codes 45, 47 and 130, even after clearing them multiple times. During our several calls and emails, where I learned how to connect the handheld, they explained the running rich condition, and chasing down several possibilities (reviewing settings, testing injectors, adjusting IAC, full ECU reset and firmware update), I ended up sending the ECU for testing. FiTech returned it saying it tested fine on their engine. They suggested I verify wiring, checking grounds and for a short.

Meanwhile, while the center console was removed, I decided to tackle a shifter replacement to see if I could improve the throw to 3rd even more, so I replaced the B&M 45052 with a MGW F-Body, and discovered that one of the mounting bolts was larger than the others - looks like it was stripped so they tapped a larger hole (not sure if this is a common practice). I wondered whether the builder or seller's mechanic had done it. Wanting to make it right, I installed a TIME-SERT insert with the proper thread and installed the MGW with its four supplied screws. Having not tried it on the road, I'll reserve my judgement, but it's definitely harder to put into reverse. (Let's save reverse lockout for another day.)

Armed with a new multimeter and power probe, I began checking for faults, pulling fuses and visually inspecting wires. Leading to my AC Delco 12617229 starter, I saw a yellow wire had been clipped (seemed intentional). It also appeared that the purple wire with a ring terminal wasn't connected to the starter. Was it supposed to be? I researched and found a pigtail to use for this starter, installed it, but the Coil/Inj D fuse still blew immediately in accessory mode. I have since, disconnected that pigtail (though it would be easy to reconnect it.)

While I was under the car, I noticed that one of the transmission bolts wasn't screwed into the bell housing. Turns out that one was stripped too and there was evidence of Loctite or JB Weld on the threads (what's up with that?). Am I wrong to think that this is important to fix and that the last mechanic to reinstall the transmission was at fault?

I also found a pink wire with a black stripe dangling near what I think is the horn relay/key warning buzzer at the driver's side front of the car. I tried plugging it in but haven't noticed any differences in operation. I don't think this is related and don't know whether to leave it connected or disconnected.

I've wanted to discuss all of this with the builder, but the seller will not provide any contact info. I was told it's a father-son team that does one build per year. Neither the builder (nor the seller) owe me anything - it's just really a spectacular car and should be running as it did before that Sunday drive.

My questions are:

• Specifically, how do I diagnose this fuse that keeps blowing? I have a multimeter and a power probe, but don't know how to start.
• I've unhooked the ECU, turned the key to accessory and the fuse did not blow. Since the ECU controls the whole operation, that's probably not telling us that the ECU is the culprit, right? Should I crank the engine without the ECU connected. (I'm thinking that's a bad idea and it won't give enough info anyway.)
• I have tested both relays in the FiTech unit. Each clicks (opens?/closes?) when I apply voltage.
• I have not been able to see/test the ignition switch wiring because it's covered by all the ductwork for the Vintage Air system. Would it be important to do this?
• How can I determine how the starter should be connected? Should the purple wire (with pigtail and connector for this starter) be connected? What's the significance of the yellow wire (clipped) that's not connected?
• I'm open to paying an expert on a Zoom or FaceTime call. Anyone interested?

Thanks for your time and consideration.

Dave