91Q - Hard Start

[tl91Q]

Hello:

About a week ago, my 91Q started having difficulty starting. This seemed to coincide with the weather turning cold.

After it has been sitting for 1 hour or so, it will not start on the first try. The engine will fire, and it sounds like it has started, but then it will die after about 1 second. I then crank it again and it will not start unless I floor the accellerator to WOT. The car then seems to run fine.

I took it to a mechanic to measure fuel pressure and he said all of his measurements were within spec.

I then took it to the local Infiniti dealer. They said it was a bad MAF sensor. They replaced it. I got the car back from them today (they had already started it when I got there) and it still has the same starting problem after it sits for awhile.

I don't have a lot of confidence in the dealer. Any ideas?

Thanks,TL

[tl91Q]

...here's a little more info...

The car has 126000 miles on it.I had the injectors and the under-plenum hoses replaced about 1 month ago to fix a rough idle condition...

...I replaced the fule pump about 1 year ago...

[DAEDALUS]

Did your mechanic who measured the fuel pressure do a rail leak-down test? Sounds like a leaky injector to me. Any black soot coming out the exhaust, or heavily rich smell? How's it idle when you get it running?

I'd get my money back from the dealership if I were you.

[tl91Q]

I did not ask for a rail leak down test (new to me). I do not notice the exhaust color, but there is a rich fuel smell. It idles great now that they replaced the injectors last month. It's just this wierd startup thing.

I'll ask the dealer to check these things when I take it back.

[DAEDALUS]

Sounds like a slow leak past one or more injectors. Hopefully you're not at risk of hydrolocking. Pull each spark plug and see which one is wet with fuel or is followed by a strong fuel smell.

[911/Q45]

Injector Oring? Take it back to the dealer to reinstall correctly.

[timatt]

I agree with those above. You likely have a leaky injector o-ring. This is the exact same problem I had a month ago when I replaced my injectors. You can verify this by doing the leak-down test mentioned above. Put a fuel pressure gauge on the fuel line at the fuel filter. Run the car briefly, then shut it down. Observe the fuel gauge. If you can see it drop slowly after the engine is off, you have a leaky injector, probably due to an o-ring being damaged when the new injectors were installed. When they install the new o-rings, make sure they lubricate the new o-rings with silicone grease to prevent damage upon reinstallation in the fuel rail.

[PalmerWMD]

Looks like you need to have a polite but firm word with the service advisor.

Fred

[rover3l]

Did this problem ever get resolved. I now seem to have similar symptoms