Good morning all,

This is my first post on the forum so please excuse me if I am posting in the incorrect location.

I have been experiencing major issues with starters over the past several months.

I have a built motor LT1 with a A&A v3 Si supercharger, GPI blower cam, long tube headers.... (if more information on the build is necessary i will provide later).

The car was built about 1.5 years ago by a shop in north Texas that I prefer not to state since they are prominent in the the corvette scene and build some phenomenal cars.

The issue:

After about a year of driving the car (about 5k miles put on the build) I began having real trouble with the starter not being able to to crank the motor hard enough to start while the motor was warm. i chalked it up to a bad battery and replaced it this marginally improved the symptom as it would start (barely) I couple days later i drove the car and it stalled (due to what I now believe to be a rough tune). when I attempted to restart the motor i immediately smelled electrical burning (just like when you burn up a subwoofer) and after investigating i found the starter trigger wire had caught on fire. I extinguished the flame and got the car hauled back to he shop that built the motor and they claimed the starter was old and needed to be replaced but that the trigger wire was in fact fried, i asked them to solder the new wire in place and i was told that solder would just melt due to the proximity to the headers. This was strange for me to head since I have background in high end car audio work and everything we do is soldered. Regardless i accepted it and they got the car back to running with a new starter. It ran fine, for a week. i was in the course of moving at the time and took it to a general auto repair shop and asked them to replace the starter. They did and stated that the previously installed starter was heat soaked and a new one would need a heat blanket. This was strange to me since I don't believe there was ever a starter blanket installed for the first year of having the car and i never had any issues with it (also the car has always had the OEM starter heat shield). I shrugged and said okay. after getting that completed i took it for a drive immediately and the car stalled at a redlight (due to a rough tune that i will later get to) and was unable to restart, I immediately smelled electrical burning and opened the car up to see the started was smoking. At this point i had the car towed back to the last shop that replaced the starter and asked them to warranty the car part and they did but then the car was unable to run after the repair was made. This shop refused to do any other diagnostic work and fully blamed the tune. at this point I was tired of dealing with shops and I too kit to my house where i had just installed two post lift.

over the course of the following month i replaced the following components:

1. two new batteries
2. new alternator (after data logging the car idle i saw enormous spikes in voltage, new alternator fixed this)
3. two or three starters (one had a defect on the trigger wire terminal that was not properly connected to the solenoid) both from AutoZone (i did not install the heat blanket on them either time)
4. crank position sensor
5. power cable from fuse box power lug to starter power lug
6. started working with a tuner to correct my issues with the original tune.

The car was having tremendous issues that prevented it from running longer than half a second after cranking, so i got a tuner to help rework the tune. At this point the car started both cold and hot beautifully in my garage and it was time to start logging the car while driving. Unfortunately the car decided to die at ta stoplight again after driving 1.5 miles max and i had to push the car out of the road because the starter wouldn't event turn the motor over a full rotation before giving up. i came back the next day giving it 20ish hours to cool off and attempted to restart the car. It did restart but barely and I was able to drive the car back to my house last night. After turning the car off it cranked extremely slowly and acted as though it was about to give up so I left it alone.

What should i do?? I feel like i am running in circles.

 

May be a thrust bearing issue killing your starters. I would try turning the motor over by hand (socket on crank bolt) to see how hard it is to turn over. Pull the plugs if you want to remove the compression resistance.

 

Its a bit of a process to do that since i have a centrifugal supercharger setup installed. I cannot get a socket or wrench on the crank pulley.

Why would this not cause issues after a new starter is installed? with a new starter is spins fine! only after driving does it have issues...

 

So you installed a power cable from the battery to the starter…what about on the ground side which is just as important ??…do you know how to do a voltage drop check on the starting system ??…you would need to go from battery negative all the way to the starter case while attempting to start the car…what does your DMM show ??.. if you see 5 volts only 7 volts is getting back to the battery…all the current from the starter has to get back to the negative terminal of the battery…if your DMM is connected on the battery terminals what does it read when trying to start it when cranking slowly ??..you should take any mechanical issues off the table too…an elevated ground can cause your voltage spikes.

 

While I have not conducted a voltage drop test since replacing many of the new components I have installed a 2/0 awg ground cable for the passenger cylinder head to the chassis ground located directly next to the alternator. I saw that this was down in some c7 and Camaros that have slow hot starts. This has not seemed to change much. I can conduct a voltage drop test for sure this evening.

What I don’t understand is what is causing permanent damage to the starters only when it drives. When idling or just starting in my garage no damage is don’t to the starter. Once it’s driving within 2 miles they are getting smoked. It’s bizarre.

 

Are you positive the starter is releasing from the flywheel?
Almost sounds like the starter gear is stuck in the start position.
That would burn up your starter pretty quick.
Have you checked to see if the shims are installed per the correct procedure?

 

now that is a great point. The starters I have been installing are from AutoZone and don’t have shims with them. Is it common to need to shim c7 starters?

my next plan Was to purchase a tilton mini gear reduction starter. I am just noti sure it will clear my headers. I know those come with shims. What is the proper clearance for the gear to to flex plate?

 

Nothing in Service Information mentions a shim…if needed it would mention it.

 

Yeah I didn’t see anything in all data about it either.

 

This is from Alldata.

 

Haha no wonder it looks so familiar 😂

so if it’s not shin related, I can only see two items that could cause this issues:

1. heat
2. gear stuck on flex plate (but if this is the case wouldn’t it burn the starter up in my garage just the same as if I was driving? The flexplate spins with the engine (autotrans)…. My thought were running along the idea the flexplate (which has been replaced recently) may have been installed improperly or was defective.

 

It’s an interesting issue and excuse the “internet advice” you are receiving. However, we’re just searching for ideas.

I have experience with starters not disengaging. They make a horrible racket when that happens and you would know.

You have obviously looked at the Electrical side and spent a great deal of money in doing so. I think that the electrical wire frying is a clear indication of significant overcurrent. Wires just do not fry if properly loaded. I know you probably don’t want to hear this, but the common issue between the car and not wanting the run properly and not wanting to crank over is probably not the electrical system but mechanical instead. I would not be surprised if there were an issue on the supercharger, causing a significant amount of drag on the engine. Perhaps there’s an alignment issue, but these cars are pretty bulletproof in terms of being able to run if left alone and not upgraded. I don’t know much about your modification, but if possible, I would try to undo it. Remove the supercharger, and put the standard tune back into the ECU. I don’t know if that’s possible because I’ve never upgraded a car with a supercharger before. But if you put it on, you probably can take it off. At least remove it and inspect it and look for obvious signs, a drag and wear. The very best luck to you.

 

Check the negative cable from the battery to its ground point which is under the carpet ~ 1 foot in and 2 feet to the left of the battery.

Make sure the connection is clean and tight.

Check the ends of the battery cables for corrosion inside past the connectors crimp.

As stated by C5 a voltage drop test would indicate any issues as stated above.

Visual inspection would have to do if you don't have a DVM or the correct knowledge on how to perform the test.