Panoz GTWC (chassis 13) motor "missing and bucking" problem

Running Chin events at Sebring and suddenly start experiencing the motor (stock 4.6 L, 4 cam) having severe "missing" problems. Ok; spark, fuel, or air. So we change out the fuel pump, fuel filter, plug wires, both spark coils, and the plugs. Air filter looks good, it's a stock ECM with no codes, and MAF is working as it should. Still won't run! Then we get smart and put a pressure gage on the fuel rail and find erratic pressure. Come to find out that the fuel cell had many squares (not one piece) of foam and they were somewhat deteriorated And the rubber fuel feed line in the cell which is attached to a collector at the bottom of the cell had become twisted as it had moved around so much that it was pinched and cut off a lot of fuel flow! Mystery solved $$

Are you running pump gas? Most fuel cells, foam, and hoses do not hold up well to pump gas with ethanol. The cure is to run Stabilz additive or 100LL Aviation Fuel.

I think the problem is that the fuel cell and plumbing may be original to the car or at least 10 years old.

I think the problem is that the fuel cell and plumbing may be original to the car or at least 10 years old.

certainly age is a factor, but the percentage of ethanol in today's pump gas speeds up the process. I found an interesting note on an ATL fuel cell I recently purchased. It stated the cell was safe to use with E85. I thought that was odd, so I started reading on the internet and found several forums and articles talking about fuel systems that are incompatible with gasoline that contains ethanol, how ethanol will dry-out rubber fuel lines, accelerator pump diaphrams, etc. I've purchased foam in the past that clearly stated "dont use with alcohol". I know some of my buddies that ran alcohol in their sprint cars, and they made sure to completely drain the fuel systems between weekends.

I'm just offering an alternative idea.

Thanks, Mark for your perspective. I do run fuel stabilizer and the new fuel cell components are from Fuel Safe and they state their components are E85 compatible. Do you run any Chin events at Sebring?

Do you run any Chin events at Sebring?

I ran two PDX events but I'm actually selling my car. I'd love to keep it but reality set in. I have another project (1955 F100) and I'm trying to finish my property in the North Carolina Mountains. I don't see myself racing this car for another 2-3 years, so I'm selling it. If you know anybody in the market for a Panoz, I'd appreciate a mention. :bigthumb:

As a last resort you can always try Hayes Harris at Wire Wheel; at least he is some what local to us, but you will likely only get "trade-in" value.

Do you have any spares you want to sell?