There was a drip of fuel leaking from I think the fuel pressure regulator. So I un bolted the fuel pressure regulator, took the clip off the line, pulled the fpr off and saw some junk in there in the screen going into the fuel rail. I cleaned that out and decided to put it back together. After fumbling with the clip I thought I got the line in, but the car started right up and fuel came pouring out of the line. So I made sure I got the line in right and tried starting again. It started fine, but about 10 seconds later stalled out. After a couple tries right after turning the key off the car stumbled, coughed and a small puff of exhaust smoke came out of the air filter. I have no idea what I might have messed up. To my knowledge everything eventually went back together the way it is supposed to. What could the problem be?

 

More info while waiting for my responses

new o rings on injectors, new fuel pump. Cycling the ignition several times before trying to start does not help and I can smell fuel after trying to start. I don't have a fuel pressure gauge to check the pressure, but I am having difficulty just pointing the finger at a faulty fuel pressure regulator since it worked fine then I took it out and put it back in and now it won't start.

Are there any obvious things I may have missed while taking it off and putting it back on? What could my fuel drip have been to begin with? I was thinking a bad o ring on the fpr, but it seems ok.

 

Have you checked the vacuum compensation line to the fuel pressure regulator for wet fuel - sign of a damaged fuel pressure regulator? If the FPR was leaking fuel through the diaphragm, it might explain the presence of wet fuel at the regulator.

 

the vacuum hose was definately dry when I started and I'm fairly positive still dry in the end

 

Did you double check the wiring? Sounds like you may have an injector connected incorrectly.

Is the regulator still leaking?

 

I didn't take the fuel rail off the manifold or disconnect the injector wiring. I don't know if the regulator is leaking anymore because now the car won't start

 

any other ideas? I'm at a complete loss here. short of just replacing the fuel pressure regulator anyway I don't know what to do. I have two other fuel rails and was thinking about stealing a fpr to test, but they don't have o rings or the screen on the part going into the fuel rail.

I guess there's a possibility the not starting is unrelated to the fuel, but that seems like it would be a huge coincidence

 

First, check the fuel pressure.

Second, look for a leak at the FPR. The engine doesn't have to be running for it to leak. Just pressure the system by turning the key on a few times.

What kind of "junk" was on the screen for the FPR? The FPR is on the return side of the system, so that "junk" had to pass through the fuel rails to get to the FPR. Your injectors may have some "junk" in the screens as well.

 

I'm still trying to figure out how you would actually change the o-rings on the injectors without removing the fuel rails or even why you would change them.

Regardless, when was the last time you changed your fuel filter? Anything big enough to clog the screens on the FPR should have been caught by the filter.

 

I'll do that Fred. If it's leaking should I just go ahead and replace it or what next after that? The junk looked like a couple acorn crumbs from a squirrel or maybe small metal shavings. I honestly didn't look real close. It might make more sense from my explaination below.

The injector o rings were replaced a couple months ago when the fuel rail was off. I replaced the fuel rail with a 96 corvette rail and didn't want to pay for new injectors, but went ahead and replaced the o rings just for peace of mind since the engine is used going in my '35 Ford. The car had been running fine except for this leak. The fuel filter is new 0 miles, less than an hour on it, but it is certainly more than likely there was "junk" in the fuel rail before putting it on this engine. Like I said though the car was running fine with the exception of the leak so all that could be wrong I assume would just be anything I did on the leak fix unless someone flipped a switch on it

 

I started tonight by trying to start it a couple times. it still wouldn't start, but to add to it, after a couple tries the car was completely dead. nothing at all. I thought maybe the battery was just really really low from cranking, but several minutes later it would crank again.

cycling the key several times did not produce a leak. the way it was leaking before it was only one drip every ~20 seconds. the first drip would dry on the manifold before the next fell. so I am not sure I can assume it would not start leaking after running for a minute. I tried switching fuel pressure regulators with another, but the other one is not as deep where the hard line on the rail connects so the line didn't fit on and I just stopped there.

anyone know off hand if a fuel pressure gauge is something that advance auto and places rent?

 

I don't know if you can rent it or not but they're cheap...you might just buy one for future work.

Is there fuel present at the schrader valve on the rail? If so, are you sure the injectors are firing? Is there any possible way you could has knocked loose the opti harness on the passenger side of the intake messing with the fuel lines?

 

There is fuel at the schrader valve, but I pressed it to relieve pressure before removing the fuel pressure regulator. Is that not something I was supposed to do? Could you explain the correlation between the fuel at the schrader valve and the injectors not firing? It's unlikely the opti harness was knocked loose because I haven't taken that fuel rail cover off during any of this.

Thanks

 

He's asking FIRST.... is there fuel present? After you turn the key to "on" and the system pressures up, it should squirt out when you depress the valve core. If you don't have fuel present, it won't start. There is nothing wrong with depressing the Schrader valve core to relieve pressure before working on the system. The next time you turn the key to "on" pressure should be restored.

If you do have fuel present, you have passed the FIRST test. He's asking a SECOND question - are the injectors firing? You could listen with a stethescope, or attach a 'noid light to verify.

Time to check the pressure - a test gauge is about $35. Also time to check the PCM for codes. Loss of low res pulse signal from the optical cam position sensor in the Opti causes the PCM to shut down the fuel system. If that was happening, there would be a code. That's why he asked about the connector on the passenger side of the intake manifold.

 

Sorry, I could have been more clear. Injuneer explained my thoughts perfectly.....