I did a search and didn't come up with much on a TPI flooding problem, so I thought I'd post this for future reference. I'm a points/Holley guy, so if this is old hat for the TPI whiz's, sorry.

89 Formula 350 twin cat daily driver (nearly stock) crapped suddenly on me and wouldn't start. I could smell the raw fuel out the exaust. Pulled a spark plug and it was dripping wet. No codes.

So I looked at the wiring diagrams and saw that injectors had 12v tied to one side, so ECM must output 0v to fire them, I thought. So I dropped the ecm, shaved a little insulation off the 2 wires controlling the injectors and checked while on, but not cranking. Near zero v. So I pulled the Hypertech chip ( a Christmas gift many years ago - no raggin) and installed the stock one.

Fired up. Problem fixed? Nope. I rapped the ECM case and the engine skipped a beat, smacked it hard and the engine quit completely. Cranked it a little, flooding. So I got a replacement ECM and it fired right up. Smacking the replacement ECM caused no problems.

So far, so good. Good enough to severely embarass the guy in the SN95 GT who must have mistaken the 'bird for an L03 while I was test driving it on the Border Highway.

I'm pretty sure problem is fixed, but would appreciate any input on other possible causes in case problem reappears. Thanks.

 

how many miles are on the car? injectors might be leaking really bad. or it could be a fuel pressure regulator gone bad too i think.

hope that helps

 

Just went over100k. Ran like a champ all day today, so I'm thinking it was the ECM. Man I had to change the oil cause it dumped a bunch of gas in there. The ECM was holding the injectors wide open it looks like. Lost about a 1/8 tank of gas, just from cranking the engine. I'm just glad it didn't hydraulic the engine.

Everyone always says Hypertech chips are a waste, but I feel a definite loss in the midrange with the stock chip in. I'm going to run it for a week on the stock chip, then if it's still running good, back in goes the Hypertech.

 

I've seen it happen to 4th gen cars with the PCM under the hood, but I've never heard of it in 3rd gens.

 

To complete the injector circut, the ECM grounds it to get it to fire, when it doesn't ground properly, it causes that to happen. That should fix it fine, but you may want to do an oil change, you may have washed the cylinder walls with gas, and have some in the crank case.

 

As bad as the car was smoking when it cranked up, I figured there was gas in the oil. Oil came out thin as water.

But there doesn't seem to be any long term ill effects.