: Please Help with long cranking time
04-05-09, 06:34 AM
So to start off the car is a 96 sts. Since i bought the car, about a month ago it has had trouble with long cranking time before start up, it is very hesitant after it starts but idles up and runs flawlessly after that. So the first thing i checked was the FPR, and found no leaks with the car idling and car off key on. And there was suction coming from the hose attatched to the FPR. I did smell the hose and it smelled of fuel but none was present. So next thing was fuel pump, because spark plugs were brand new iridium pre gapped. Had the fuel pressure checked and it was about 35, so the fuel pump was replaced. New fuel pump in pressure was steady at 45. Still the car did the same thing upon startup. No help there, the car will crank for about 5 seconds when left for 30min or more. Hot or cold starts no different. The next thing i tried was priming the fuel lines by turning key to on, then off, then back on, then off, then start and it fires right up, no hesitation. I know a leaky injector can flood the engine causing long cranking but I tested by putting gas peddal to the floor on startup and still cranked for about 5 seconds then started and reved right up. There is also no smell of fuel under the hood or in the car. So if someone can please tell me if the FPR can be shot without it leaking? How can I check if the FPR is holding pressure? Ive read on previous posts that a bad O ring on the FPR can cause my exact symtoms without leaking fuel. I really dont wanna spend $150 for a FPR thats not leaking unless its the proplem here, especially after spending $500 on the fuel pump. Any help would save me from pulling out more of my hair. Thanks
The way to test the FPR is to put a hand held vacuum pump on it and pump down a vacuum. The watch the gauge and see if it holds. If it holds vacuum and does not leak it is good. Also check the fuel pump relay. If it is bad, then the pump does not get energized until enough oil pressure is built resulting in long crank times. You should hear the fuel pump run for 2-3 seconds with your ear to the open filler pipe while someone turns the key on.
04-06-09, 02:22 AM
Thanks for the response Ranger, It seems that replacing my fuel pump has gotten rid of my cold start problems, but its still cranking for too long after sitting for 30min+. Since ive replaced the pump the first start of the day it starts right up, but hot starts it still cranks for about 5 seconds. I found a handheld Vacuum-Pressure Tester but it doesnt seem to have a pump on it. Will this work? Ive posted a picture of the unit. If I check the fuel pressure after the car has been shut off and let it sit with the gauge on, will this tell me if the FPR is bad of just that I have a pressure loss in the system? Does this sound like a leaking injector at all? Thanks again
04-06-09, 10:15 AM
The hand-help vacuum pump would let you induce a vacuum on the FPR's nipple and you could observe if the vacuum drops and at what rate. If the diaphragm on the FPR is compromised, you should be able to notice a steady drop and also gasoline will be pulled into the pump. Usually, a bad FPR will cause hard starts when the engine is warm or hot as the leaking gasoline into the vacuum line will make the mixture too rich. It's hard to diagnose an injector, but if you listen to each one with an auto-stethoscope, they should have a rhythmic pulse or rapid ticking sound. You mentioned that you could smell fuel at the FPR's vacuum line which is a tell-tale sign it could be shot.
No, that vacuum gauge will not help . Take a piece of vacuum hose and put it on the FPR nipple. Now suck on it to draw as much of a vacuum as you can and then plug the end with your tounge. If the diaphragm is good it will stay stuck to your tongue as it will hold the vacuum. If it has a leak, it will eventually fall off. Not quite as good as a pump and guage, but it'll do.
04-06-09, 01:11 PM
Here's a shot of the vacuum pump in Ranger's post, and one of the pump and a gauge similar to yours.
That is EXACTLY the one I was talking about and own (both as a matter of fact).
04-07-09, 09:19 PM
Thanks for all the responses guys. So I tried the manual vacuum on the hose and it holds suction for about 2-3 seconds then falls off. This of course was when the car was idling. Hope thats when Im supposed to test it. So does this mean the FPR has gone but just hasnt ruptured the diaphram?
Try it with the engine off, though it should not matter. If it does no hold vacuum, the diaphragm is bad and you should be pulling fuel through the nipple.
04-12-09, 04:45 AM
Thanks everyone for your help, Ive finally fixed the problem thats been plaguing me for over a month now. After a new fuel pump, battery and spark plugs the problem has been traced back to a carroded O ring on the bottom of the FPR. Yes this was a 80 cent fix for a problem that ive thrown $600+ at. And the FPR was not leaking so at least I saved another $100 on that. Hopefully I can help someone from making the same mistakes I did and check the O ring before doing anything more drastic and expensive. Thanks again
08-02-09, 12:59 AM
well doing a "hard Start" search, I have found this thread, thanks very much I'm going to check my O ring in the morning as I am experiencing the same symptoms