Maverick7687

I have a 1990 TT that has been sitting for while.. It had a bad PTU when I got it so I got a new one with sub harness. Changed them out and when I started the car it backfired and died, then all it would do is crank, no startup.. Took the PTU back out and started trying to locate the problem, I am guessing it is a short somewhere.
Anyway I have a parts car which is a NA 1993 (Got it for the interior my TT is missing) and i have the PTU that came with it, but I want to make sure the problem is fixed before I blow another one (those things are freaking expensive!)

I have the FSM and I have looked at the part where it shows how to test the PTU but the two that I have don't have the abcdefg part. On one side it has E1-6 and the other side has 1-3G4-6.. When I ohm them across they all read nothing. On both units.

Someone please help me get this thing on the road. I have had it for over a year and I am just now getting time to start work on it.

Oh, the previous owner wired in the new coil pack clips for some reason (are the coil pack different between the 90 and later years?) and installed with just standard butt connectors.. I am cutting and soldering them hoping I will find a shorted/corroded wire somewhere. Also, the rear clip on the driver side (My memory is gone at the moment so I am not sure which cyl that is, the one you have to pretty much remove the equalizer bar to get to) the tab that holds it on the coil pack. I am hoping my short will be somewhere in these wires, where else could it be?

I am wanting to get the car to start and run before I pull the motor and do the 120k kit so I can figure out if I need to focus my attention to a particular thing once it is out. I would hate to pull it, delete everything I can, do the 120k, check turbos, etc. just to put it back in and have something else jacked up.

Any help would be great guys. If all this info is contained here somewhere someone please point me in the right direction, I have searched PTU, PTU testing, PTU blown, PTU Sucks.. everything I can think of and can't find anything like this.

Thanks.

KasbeKZ

so you have a PTU problem and a coil pack connection problem both on the same car? you don't think that possibly the coil pack connection is the only problem? or is it two different cars with two different problems? got a little confused in the forth paragraph.

Maverick7687

The coil packs that have been rewired are on the same car as the suspected PTU problem. I am thinking that something in the way the coil packs were wired is the reason the PTU popped, if that's even what happened since I can't get the PTU to test correctly. Now that I think about it I am going to hook the suspected bad one up in the other car and see if it starts.

Anyway, Yes, both problems, same car, I was just fishing to see if someone has had a similar problem.. When it died the last time it was started it popped (backfired) and sounded like someone shooting a gun at the rear of the car. Couldn't get it to start back which is why I was thinking the PTU blew, and I was also going by what the previous owner said happened in the past which was a bad PTU.

Does that make sense now, sorry about everything being jumbled up, been awake too long.

Maverick7687

I switched them out and put the 'bad' PTU in the car that runs and it wouldn't start, so the PTU is officially bad. Now I need to know what kind of shorts/problems would kill the whole unit and not just one particular circuit. If it was one of the coil packs it would be just that individual circuit, correct?

CM4T4

I am having a similar issue with my car and believe its the PTU. I don't have a back fire but it isn't catching when turning the engine. Did you ever find out what was happening?

Heu1124

Did you find out what was the problem?....I'm have the same problem....it seem to be short somewhere and PTU gets very HOT!....What did you end up doing to solve?