Crimson Nape Racing

Looking for suggestions. 96 with 3.8 and a modified ECU (of unknown origin). Twice about 1 year apart it wouldn't start, both times after driving, but would start right up like nothing ever happened after 3-4 hours. Tried the DME and no luck. It turns over & gets gas (you can smell it after just a couple cranks) but absolutely no fire. Last night it died in traffic while running and now it won't start. I guess this is a good thing because maybe I can figure out what's wrong.

I'm about to take the IC off and make sure all the wires are connected. What else should I look for? It appears to me to be ignition related.

Thanks.

Basal Skull

is it single or twin plug? there aren't that many vendors who modified the ecu for 3.8. Some of the modded ECU's were based on the 1996 ecu that required a piggyback chip and sometimes the chips needed to be reseated or pushed down (often with a sponge glued to the inside of the ecu cover to keep the chip seated would collapse) - it was the connection on the chip that would get some corrosion, they could be soldered in to make them more reliable. 1997 ecu's didn't have this problem as they could be reprogrammed.

OverBoosted28

You wanna hear something really bizarre, I sent a pic of my ECU to Steve, to see if he could tell me what it's from (stock one is stored). He said it was outta a 98 C2, and had never seen a C2 ECU used in a TT.
OP: what I do on a regular basis, is after cleaning, I put dielectric grease on all electrical contacts. Helps maintain corrosion free contacts. Good luck.

Crimson Nape Racing

It's s single plug and I talked to the company that did the ECU but can't find my notes. I'm thinking they were in Arizona? I'll pull the seat and check the ECU this weekend.

This may be a stupid question, but can I see if the car will start with the IC off the car?

Crimson Nape Racing

The plot thickens; the ECU is piggybacked, but it is epoxied in place. The distributor wasn't great but not bad enough to not run. The kicker was I sprayed a little starting fluid and it tried to start. So if I've got fuel, and I've got spark....

Basal Skull

Richard, yes I've been told c2 ecu's work in our cars, just need an external boost controller. I believe protomotive did some that way. I've seen/been in cars (with ecu's meant to be used with external boost controllers) run without external boost controllers, that boost okay/reasonably when you roll on the gas but if you stomp on it, it'll boost to 2+ bar and go like stink but motor may not last very long. (You'd be surprised how tough our engines are..)

Bob, some cars run/idle rough without the ic, others don't.. You can try.
That looks like the chip itself is not epoxied, just the chip receiver, I'd give the chips a firm push and see what happens.

Crimson Nape Racing

I read on here "more testing and less guessing", so even though I smelled fuel I jumped 30 and 87b - nothing. Then I disconnected the fuel line at the rail and cranked (with a hose on the line) - nothing. not sure what the fuel smell was while cranking; possibly not enough to ignite?? I only smelled it when it first died, while cranking it the last day or so I didn't notice, but now that I think about it I haven't smelled it.

speednme

Had a 911 once that would do the same exact thing ...even happen to me crossing the Williamsburg Bridge in Manhattan...luckily I was able to roll it to the bottom of the bridge. Once there, she started right up and I drove home with no problems. Took it to the wrench the next day...turned out it was a bad fuel pump.

Mike J

I also have seen the same as Rey - on one car, it was intermittent, replaced the fuel pump and no issues since. Same characteristics. Hard to diagnose and prove since it was intermittent.

Cheers,

Mike

Basal Skull

I'd try the simple things first, change the fuel filter (when was it last changed?).