jmc1986mj Posted March 16, 2009 Share Posted March 16, 2009 So I rescued my '86 from a couple kids in Payson, AZ... Today I replaced the starter, fuel filter, fan shroud, serpentine belt, battery, and engine oil/filter. Cyphoned the bad gas from the tank and replaced with fresh. Engine turns, but will not fire up. Should you be able to hear a fuel pump whine when the ignition is turned on? My Chevy truck does it and I believe the '89 Cherokee I had did too. It seems like the issue is either the fuel pump or something else electrical. Any hints? So far, offering up a little TLC hasn't been enough to coax this rig into behaving. Perhaps I should give it my wallet, er wait, already did. Thanks all! Link to comment Share on other sites More sharing options...
bigd44889 Posted March 16, 2009 Share Posted March 16, 2009 u should here the pump check pump relay and fuse check for spark if no spark replace cps :cheers: Link to comment Share on other sites More sharing options...
dasbulliwagen Posted March 16, 2009 Share Posted March 16, 2009 Ive never heard the pump in mine... I think if you can hear the pump standing outside or inside the vehicle, you should replace it! Check to see if you have spark, if not, probably the crank pos sensor. If you do have spark, get under the truck and put a stethescope on the tank, or put your ear up to it to see if the pump is running while you have someone cyle the ignition key without starting the truck. It should come on and run for about a second or two before shutting off with the truck not running. If not, take your hammer and rap on the tank a few times. Sometimes this will jar the pump into running, at whick point you know you need to replace the pump. Depending on how old the gas is, it could have gummed the pump up bad enough to cause it to have a hard time starting. Good Luck! Link to comment Share on other sites More sharing options...
BLHTAZ Posted March 17, 2009 Share Posted March 17, 2009 You should be able to hear the fuel pump for just a couple seconds when you move the key to the on position as it pressurizes the system. If you are not hearing anything, then you should do a fuel pressure test to be sure, but it would seem that there may be a problem. Hearing it is a good thing on these trucks. Link to comment Share on other sites More sharing options...
Tomahawked Posted March 17, 2009 Share Posted March 17, 2009 If there are any buzzers making noise when you turn the key, fuel pump won't be heard. Fortunately the fuel pump is very accessible and easy to remove. Have someone tur the key to run while you feel for the relay to click. Check fuses, etc. Depress the valve on fuel rail to check for fuel pressure after turning key to run. It should spray, not dribble. If nothing, remove fuel pump from tank after removing fuel down below hole in tank. If truck has been sitting up a long time, its possible varnish is present. I had a clean tank even tho truck had been sitting up for 5 years. It started and ran, and a few days later would not stay running and stall out. Problem ended up being the short piece of rubber fuel line where pump connects to hard line on sending unit in tank. The rubber line had basically disintigrated. Link to comment Share on other sites More sharing options...
glundblad Posted March 17, 2009 Share Posted March 17, 2009 I am confused. I could always hear the pump, even when new. Particularly while standing on the drivers side at the rear axle. I sounds like an air leak. It does it now with a fairly new fuel pump. Is my truck the only one that does that? Link to comment Share on other sites More sharing options...
Ed in North Ga. Posted March 17, 2009 Share Posted March 17, 2009 I am confused. I could always hear the pump, even when new. Particularly while standing on the drivers side at the rear axle. I sounds like an air leak. It does it now with a fairly new fuel pump. Is my truck the only one that does that? nope- thats common. But I have run into a few that were very quiet and still worked fine. Could be any number of reasons. The one on my 89xj was getting noisey at 250,000 mile so I replaced it (my first tank drop...that laned on me) I still have that pump, it was OEM 89, and still use it every now and then to transfer fluids around the yard. My 89MJ was noisey when I got it- it aint comeing out till it dies. the 86 w/2.5 has a pump inside the tank, or exterior? I forget... Link to comment Share on other sites More sharing options...
BLHTAZ Posted March 17, 2009 Share Posted March 17, 2009 I am confused. I could always hear the pump, even when new. Particularly while standing on the drivers side at the rear axle. I sounds like an air leak. It does it now with a fairly new fuel pump. Is my truck the only one that does that? Nothing wrong...as I said above...you should here it. When I start my truck, I always turn the key to the on position, wait for the pump to stop and then start the truck. I can hear it run for about 2 seconds to pressurize the system. Link to comment Share on other sites More sharing options...
mvusse Posted March 18, 2009 Share Posted March 18, 2009 No time to reply this morning, but I can hear my pump. Link to comment Share on other sites More sharing options...
Tomahawked Posted March 18, 2009 Share Posted March 18, 2009 OK, you have a fuel pump running. Now you need to figure if there is any fuel pressure. Depress the valve on fuel rail after the key is turned to run. It should spray out, not just dribble down. We can do baby steps with this. So one thing at a time. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now