[KesslerR]

If you remember my problems from Hard starting I through III, the answer was the last place to look. I changer hoses, injectors, check valve, filters, you name it I changed it and the car ran great, but starting got worse and worse. It was so bad I was embarrassed to go anywhere I had to shut the car off and start it again.

Where could the gas go but back to the tank some way. There was never any gas smell or leaking gas, so where did it go? I had a pressure gauge mounted on the fuel rail and every time I shut the engine off the fuel pressure went to zero in a minute. I took the return hose off at the fuel rail and no gas came out of the return on the regulator.

Took the whole system off the engine and pressurized it on the bench. There was the answer. the fuel was leaking, no not just leaking, being sucked out of the vacuum side of the fuel pressure regulator and through the vacuum hoses back into the air intake of the engine.

New fuel regulator and it starts instantly, idles properly and gets better gas mileage. Even the factory manual which has a page on how to track down a fuel pressure problem never said to look at the vacuum side of the system.

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[banditsc]

Yep, it can happen, the rubber diaphragm breaks down and starts sucking gas into the vacuum system. The quick test for that is to pull the vacuum line on the regulator and smell it for gas.

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[unknown4u]

Due to age this part will also fail. I already changed is some years ago. Mine was broken, because the valve stuck in the open position. So no pressure was build so there would be an vapour lock issue. The car was hard to start when hot.

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[DaveN]

Lately my car has been sputtering and starting with too much "starter motor" time. I think I will change the FPR on spec this winter after reading this thread. Stock one OK or should I get an adjustable billet one. Just thinking that with the SC it might help to have the ability to tweak the PSI?

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[flash]

nope. in fact, it messes things up. it doesn't behave quite like the OEM unit, and it's pretty easy to mess up the mixture. i had to put the OEM unit back on to do the tuning.

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[DaveN]

Tks Bob. I'll just get the plain Jane P model then.

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[TonD]

Dave, did you replace the FPR and did it sort things out? I'm (no surprise..) tracking down a hard-to-start issue as well...

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[DaveN]

I actually changed the check valve as a first try. I am waiting to get my engine pieces back from the painters so I can re-assemble and start the car. If the problem goes away I will report back. Still a month away from the road as I have to get an alignment done and splitter installed as well.

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[TonD]

Good luck with that <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

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