Nothing good...
My fuel pressure problem came back.
A couple posts back I talked about having fuel pressure problems on the dyno and having the car stall out on the road. So I changed out the fuel filter just to be sure. Since then I've driven the car back and forth to work and it seemed good. About 6 weeks ago I went for a long drive (like 20 miles on the freeway) to meet a guy here in town who wanted to check out the Cuda. Car ran great and I hung out with him for like an hour. It was like 92 degrees that day and so I jump back on the freeway to go home and after like 7 miles on the freeway I look down and there goes my fuel pressure. I was in the far left lane going 75 at the time. I make it over to the right shoulder and I got it to re-fire and take off again. I make it about a mile and it dies again. Same thing. Got it re-fired and make it like a 1/4 mile. Finally I got it pulled over past an on-ramp where I wasn't directly on the shoulder with thousands of cars streaming by at 70 mph.... instead I was 20 feet from all the cars screaming by.
I tried a few times to restart it and it would start the fuel pressure would come up and then it would drop and the engine would die.
Of course I didn't have any tools or anything. So I pop the hood and couldn't find anything obvious. The only thing that seemed wrong to me was that the fuel rails were really hot to the touch. The metal fuel line on the firewall wasn't. The fuel tank and fuel filter weren't hot either. So I thought to myself maybe on the freeway without a return line the fuel rails are heat soaking and it's boiling the fuel.... perhaps on the freeway it's running efficiently enough that I'm not pulling enough fresh fuel in to the rails??? So I called my buddy who was nearby and had him bring me two bags of ice. So after 30 minutes he shows up and I put the ice bags on the fuel rails and let it sit for another 10 minutes. I left the ice bags on the rails and closed the hood.
So I get the engine started and took off pretty hard (my thought was to burn some gas to get fresh stuff to the rails). I get off on the next freeway exit and decided I would take the frontage roads home thinking the stop and go might help. I make it about 2 miles or so and I'm cruising along at 50 mph in 4th and it dies again..... crap. My buddy was following me now. So I get it re-fired and get going again and told my buddy at the next place I could stop we would. So about 1/2 mile up I'm pulling up to a stop light to turn in to a gas station and it dies again. I get it started and pull in to a big AM/PM and pull in to the back. I was still probably a good 7 miles from home. After that I was so frustrated I said screw it I'm going to get my trailer. So I ended up towing it home.
Anyway I was really frustrated. It fired right up and ran fine while I pulled it on and off the trailer.... go figure. So since the ice didn't help I think that dis-proved my theory about heat soak on the fuel rails?
So the next day I start it up and let it idle a long time to heat soak. I also would rev it up and in doing so I noticed my voltmeter would go to 16V. That's not good. Plus I had noticed that once or twice while driving as well (I know I should have fixed that earlier). At the same time I felt the 40 amp relay for the fuel pump and it was hot to the touch. So I pull off the new voltage regulator and put on my 12 year old one that was on the old 340 motor and sure enough with the old regulator I'm right at 14V. So that new voltage regulator was bad.
So all I can think of is when running steady state on the freeway where its at a constant 2000+ rpm it would make the voltage go up to 16V which would overheat the fuel pump? I don't know. That's about all I can come up with. I've only taken it on short drives since then (I'm up to 280 miles on the car). One of these weekends I told my buddy I'm going to have him follow me on the freeway driving my truck and trailer and we're going to try and go for a long drive. That's all I can think of to try and cause the problem again. That way if it acts up again I'll just pull it on the trailer. I'll also take tools and a DVM with me.
If it does it again, I'm thinking I either need to replace the fuel pump or scrap the Walbro and go with the VaporWork system would would require modifying the tank. Any thoughts? The only other thing I can think of is the fuel vent isn't working? I forgot to pull the gas cap when it started acting up.... but I did take it off at the AM/PM. That's one of the things I'll try if it happens again.
So I haven't done much on the car other then planning for the interior. I started putting down the Damplifer on the rest of the floorboards. Once I get the driveshaft loop in I can finally put the carpet in.
Travis
72 Cuda
