: hot start when cold



mwillius
09-06-06, 05:52 PM
Starts great when cold. Starts hard when engine warm. Blows smoke when cold. Gas mileage terrible. Catalytic converter rattling like crazy. Fpr seeps no fuel at all. What else could it be and how do I check it?? Hope it's not the intake manifold. I do not hear the fuel pump coming on when turning the key. Seems like I would since I can smell lots of gas in the exhaust which is undoubtedly causing all the smoke when engine is cold. Engine warms up quickly.

Ranger
09-06-06, 07:43 PM
You either have a stuck open injector(s) or a bad FPR. The later is more likely. A bad FPR will not always leak when the vacuum line it removed, though it usually will. Try putting a hand held vacuum pump on it. Pump down the vacuum and see if it holds vacuum.

zonie77
09-06-06, 08:08 PM
If your cat is rattling it's broken inside. It looks like a potato by now. It blocks the exhaust and causes various problems. Replace it.

chevelle
09-06-06, 10:18 PM
Definitely sounds like a failed FPR or a stuck open injector.

Any idea what car and model year this is??

On the 95 and later Northstars it is relatively easy to unclip the fuel rail at the injector hold downs and lift the rail up so that the injectors are clear of the bungs in the intake manifold. Have someone turn on the key to energise the fuel pump while you watch. If an injector sprays fuel when the key is turned on (don't crank or start the engine....just turn the key to on) then that injector is stuck open and must be replaced.

The FPR can sometimes leak only when vacuum is present. Run the engine for few minutes and then turn it off. Pull the vacuum line off at the FPR and check for wetness or strong fuel smell. checking it with an auxiliary vacuum source like a mightvac while the engine is idling is also a good idea.

mwillius
09-07-06, 04:42 AM
Thanks Chevelle!! It is a 99 deville concours. Do I connect the pump where the vacuum line attaches to the FPR? What pressure? For $66 I think I will just change the FPR. If that doesn't help I will check the injectors. I over heated my car a month a go and the car went into camel mode. I'm wondering if it caused one of the injectors to get stuck open.

Ranger
09-07-06, 10:29 AM
Thanks Chevelle!! It is a 99 deville concours. Do I connect the pump where the vacuum line attaches to the FPR? What pressure? For $66 I think I will just change the FPR. If that doesn't help I will check the injectors. I over heated my car a month a go and the car went into camel mode. I'm wondering if it caused one of the injectors to get stuck open.
Yes. Just pump down a vacuum. 10-20 in., the number is irrelavent. Just watch the guage to see that it holds a vacuum. It should not leak down.

chevelle
09-07-06, 11:54 AM
Yes. Just pump down a vacuum. 10-20 in., the number is irrelavent. Just watch the guage to see that it holds a vacuum. It should not leak down.

It shouldn't leak down......and....there shouldn't be any fuel in the vacuum line to the miteyvac when you disconnect it. Any vacuum will do....the more the better.


It's pretty easy to lift up the fuel rail on a 99. Just unclip the lines and lift the injectors clear of the manifold to check for a stuck one.

You could pull the plugs and check them, also. If an injector is sticking it should show up on that plug with wetting, fouling, deposits, etc.