1999 SN GT40 Stalling at rpm > 1,000

[AB]

Good ideas. I am waiting on the FCC to arrive and being able to start it up again. What is odd is that the engine would make a sort of gasping sound, so that is why we all thought it was running out of fuel. At idle, it is smooth as ever.

I should have it running again this week sometime, and will go from there.

Thanks

[AirTool]

If it "gasped" as it died, it may have been rolling backwards and sending a compression stroke out the throttle body.

[east tx skier]

Have you had a look in your tank to see if there's any junk in there that may be clogging the fuel pickup? Just a thought.

[mrbobolina]

I am agreeing with Airtool on that one. The gasping poof sound is likely something outside the fuel all together. I am curious to see what you find with a compression test. The test is really simple, but you will need another person. You can buy a compression tester at PepBoys the instructions will be in the packing. The tool is like $40 if you do not have one.

[AB]

OK, nothing is ever easy.

The new FCC comes in today and instead of the black FCC I get a silver one. This doesn't have the Shrader valve on top, which might not be a big deal, but the top of it has one open hole, assume for the low pressure input line, and it has 2 other holes, both plugged. The open hole is in a place that will bump into the alternator. Can I just plug that and use the other 2 holes for the input and I think it is an overflow going back to the tank.. not sure, it is a rubber hose going down into the bilge and back. I think there is a recycling hose on the FCC, so assume this is it.

Can I use any of the 3 holes on the new FCC? the old black one only had 2 holes.

[AB]

According to PCM, the old black FCC has been superceded by the silver one. You can use any combination of holes on the top as fits. No Shrader valve. The most effective measure of the fuel pressure is up on the fuel rail anyway, so I guess that makes sense.

The silver one has a clamp at the top instead of the screw on method, so maybe they were getting too many complaints about the old ones getting frozen and having use a vice and leverage bar, as posted out here.

[AB]

Well, finally put it all together and ran it in the driveway. I think I crossed the input and output lines going up to the fuel rails (had them separated but gas leak caused me to scramble and they may have switched positions). Wouldn't run. Switched the fuel rail lines and then started up. Was leaking a little out the top of the FCC fuel rail lines, but ran it enough to see the pressure on the fuel rail was close to 40psi. Gave it a little gas and it seemed like it was going to rev and then lost pressure on the gauge and engine cut back. Was idling, but surging, like it was just getting pumps of gas, not smooth.

I am thinking low pressure pump or relay for pumps. I replaced the relay and low-pressure pump last year, could they go bad this fast?

I checked the throttle body opening and it moves okay.
???????????

[AB]

Put in both relays today and turned the key on and NO priming. The low pressure pump is only about 50 hours old.
Do both pumps prime or just the low pressure pump? I don't think I hear anything from inside the FCC either.
What else could cause the pumps to NOT prime?

[jasper]

AB, check out the GT40 service manual here: http://www.planetnautique.com/Correc...e%20Manual.pdf

Go to page 72 (of 302) "Symptom Index." It will lead you through diagnostics. The manual has been very helpful for me. It takes some wading through at times, but it is very comprehensive. All that said, just off the top of my head, make sure you are getting power to the low pressure fuel pump and have good electrical connections all the way. Best of luck to you, and let us know.

[AB]

Traced it back to the circuit breakers. Couldn't push them in, seemed to be frozen. Tapped on them with the butt of a screw driver and the fuel pumps primed. So, I am hoping that once I replace them, the pumps keep running!

Learned my FCC had a leak though, or possible leak, so that was good to learn, expensive to replace, but if it would have started leaking while under way, not sure I would have noticed under the motor box.