i think i have a bad fuel pump on my 86 cav conv. with the 2.8 v6. hers the story. the car always fired up on the on the first turn of the key, then a couple of weeks ago it would start rigth up then die immiediatly. this would happen 2-3 times and then it would stay running a little rough at first but then smooth out and then run fine. now the car will crank but will not fire. i do not hear the fuel pump run when i turn the key like i alwas did before. another thing that comes to mind is i was hearing a faint noise comming from somewhere in the back seat/trunk area when the car was running. it sounded like the covertable top motor was running but now i am thinking it was the fuel pump telling me it was going bad and it just did not dawn on me. i do have spark and the fuel filter is less than a year old. i need a step by step procedure to make sure its the pump. i dont want to drop the tank only to find out it was a fuse or relay or something like that. i cant find the fuse and dont know where the relay is or how to test it. i know some cars have a auto safety shut off that cuts power to the fuel pump in case of a crash so the car doesnt catch fire. i am not looking forward to dropping the tank so i would like to make positively sure its the pump before i do so. any and all help will be greatly appreciated
John-
I will take a pic of the service manual diagnosis for my 84 if you would like...
Those are pretty close to the ones I have
Do a fuel psi check on the scrader valve.IF you can hear the pump when the key is just ON not running and reading is below spec 40.5-47psi.Keep in mind the ecm will kick on pump sending the pulse and with in 2seconds cut it off however the reading should be 34-37psi on the rail.Hope not to confuse you just in case the reading goes higher as above then drops to the lower # below.The fuel pump relay is either on fender on firewall I would have to dig out my manuals to be specific.I am tired so I tried to get this in some kind of order.
I know my pump went a couple of days hard starts,and then coughing while rolling and then just died.If it is the original odds are the pump is going bad in thought.
thanks for the schematics 84conv. my manual is a little convoluted, it refers you back and forth between fuel and electrical sections and can get a little confusing. checked fuel pressure, i have none. will go through elctrical today but i dont think i will find any issues. will post later with results.
out with the old, in with the new and back on the road!! my wife and i replaced the fuel pump today and now she is purring like a kitten. my wife that is, the cars running pretty good too!! she was a lot of help today and i could not of done it by myself. if you find a good woman, hold on to her, there hard to find. we used a friends transfer pump to drain the tank and it worked like a charm. i"m going to get one for myself.the whole job took us about 4-5 hours but we took a few smoke breaks and had lunch so i think we did pretty good. all in all a great day. heres a few pics
note fire extinguishers in background.
Wonderful Job and Great Teamwork!!
One of the advantages of owning a 1st Gen J......Cheap Fuel Pumps!!
I'm guessing the Smoke Breaks were successful as well - away from the project since nothing seems to be charred
Just curious....I replaced mine many years ago and had a major fit with the replacement after market O-Ring that fits between the tank and the knock-off ring. Are they any better these days??
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Nice glad it is fixed.Btw I thought all day and I am certain the fuel pump relay is behind the battery with out cheating to check my book.Cool
Thought the fuel pump relay was on right at the fender - tucked up near the cowl on the passenger side. Very near the passenger side hood hinge area.
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orlen. your right about the fuel pumps being cheap. if you order parts online from advance and pickem up at the store you get a great discount. i bought the pump, pump screen, locking ring and fuel filter all for 80.00 anew o-ring came with the pump and locking ring and matched the original perfectly. as for those relays, on my 2.8 the one for pump is on the firewall drivers side . the one on the fender next to the battery is for the radiator fan
This story has been a timely reminder for me. Currently in the process of stripping down a donor, and this gave me that urge to drop the tank and salvage the fuel gauge sender and piping/wiring. Might not be in the best shape but might be something to get me by sometime.
Would have not given this a thought and would have left this behind....
Have already salvaged the entire wiring harness under the hood , so I'm pretty sure I've got that relay.....where ever it was...
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Just a note , My 84 has the a/c relay and the f/p relay on the same bracket as the map sensor up on the passenger cowl near the hood hinge. A/C relay is the one towards the front and the f/p relay is the one facing the back and are interchangeable, so you can use the A/C relay to test the fuel system if you need to or try and get you home.
Just a note , My 84 has the a/c relay and the f/p relay on the same bracket as the map sensor up on the passenger cowl near the hood hinge. A/C relay is the one towards the front and the f/p relay is the one facing the back and are interchangeable, so you can use the A/C relay to test the fuel system if you need to or try and get you home.
