Have checked the crank sensorI'm trying to diagnose a intermittent cranking no start on a 2001 sport trac 4.0 it seems to only happen in cold weather. does anyone have any suggestions on how diagnos the problem when it's not happening ? I'd like to fix it before it leaves me stranded .
Not yet I assume that have to wait until it quits again to test itHave checked the crank sensor
I was leaning that way koda, but I know relays can do the same thing when they're getting ready to go out. what I'm really looking for is a test procedure that will identify a weak component before it fails completely. I want to be absolutely sure seeing that I don't really want a fuel pump for Christmas.
Thanks that's really helpful. It quit on me agan and some carb cleaner got it going again. Given the truck has 216000 miles on the original pump that's probably it. I'm going to wait for it to die one more time to test the crank sensor and relays. I've already checked the inertia switch so it looks like next time it dies I'll be getting to the bottom of this.Here's the way I prove that the fuel pump is the problem (listed in to particular order):
1. Swap the fuel pump relay with another one in the power distribution box. Also examine the relay's socket for corrosion.
2. When the vehicle wont start, try spraying starting fluid into the throttle body. If the the engine them stumbles to life, it's not getting fuel, which rules out an electrical problem (like the crank sensor).
3. Check the inertia switch's connections to make sure they're not loose, burnt or corroded.
4. When the engine wont start, try turning the key OFF/ON multiple times (may take up to 20+ tries or more) until you hear the fuel pump prime.
5. You can try testing the wire connection found on the frame rail behind the driver's side rear tire for power when the key is turned on. (requires two people and a VOM).
I've replaced the fuel pumps in all 6 if my Explorers/Mountaineers. 4 of them demonstrated the same symptom you're experiencing (1 flat out died and 1, with 260,000+ miles on it, turned out not to be the issue, but at that mileage was certainly due to be replaced). They all crapped out when the weather turned cold and all had between 160,000-200,000 miles on them.
BTW, I replaced the fuel pump on my '01 ST at 183,000 miles. Did it myself and my total cost was about $80, which included a quality fuel pump, a new strainer sock and a hard to find 3-port fuel filter.
I been having same problems what ive found out is that if i leave key in on position and go to fuse box and try pulling pcm relay fuse until u hear some noises similar to small taps then put it all the way back in and try starting it it will start its been working for me. Can someone think of something so that i wont be having to do this a the time?I'm trying to diagnose a intermittent cranking no start on a 2001 sport trac 4.0 it seems to only happen in cold weather. does anyone have any suggestions on how diagnos the problem when it's not happening ? I'd like to fix it before it leaves me stranded .
I been having same problems what ive found out is that if i leave key in on position and go to fuse box and try pulling pcm relay fuse until u hear some noises similar to small taps then put it all the way back in and try starting it it will start its been working for me. Can someone think of something so that i wont be having to do this a the time?
Have you tried replacing the relau? Check for corrosion on the relay and socket.I been having same problems what ive found out is that if i leave key in on position and go to fuse box and try pulling pcm relay fuse until u hear some noises similar to small taps then put it all the way back in and try starting it it will start its been working for me. Can someone think of something so that i wont be having to do this a the time?
Thanks that's the direction I was going. I just like to eliminate the inexpensive stuff first. I had a bad and expensive experience with a honda odyssey that turned out to be a bad relayMy money is also on the fuel pump. Get a fuel pressure gauge for about 20 bucks at harbor freight or autozone and hook up to the fuel rail. Or just have a friend turn the key to the on position while you have your ear up to the tank. You should hear the thing hum as it primes up if it is still working. The gauge will be the definitive indicator though, the fuel pump can still be running but will be weaker than normal it is on its last legs. If you are measuring with a pressure gauge it should be around 60 psi. A weaker psi means failing pump thats about to quit permanently. If the problem is intermittent, i dont think the relay will be the root cause unless your contacts are fouled up.
