Swampy Posted April 9, 2019 Share Posted April 9, 2019 What is very frustrating is the fact that I was driving my comanche all day this past Saturday (4/6/2019), I got back to my house and parked it. I got in it the next day (4/7/2019) and the jeep would not start. It ended up being that the engine was not getting fuel. I checked everything I could besides pulling out the fuel pump to check connectins. still no luck. I had just replaced the fuel pump in December. Can it go bad that fast? its a Delphi pump Link to comment Share on other sites More sharing options...
gogmorgo Posted April 9, 2019 Share Posted April 9, 2019 Been there. The adapter kit that came with my Delphi pump was junk, so it ended up pulling fuel out of the middle of the tank, meaning I "ran out" of gas at around 1/3 tank remaining. I once coasted to a stop about 200 feet from my driveway, had to siphon a gallon out of another vehicle to get the MJ started and into the driveway, then the next morning I had to siphon again and hope I made it to the gas station five miles away, and then only squeezed about 17 gallons into the 23gal tank. Link to comment Share on other sites More sharing options...
kryptronic Posted April 9, 2019 Share Posted April 9, 2019 I had a similar issue with my 91. Changing the fuel filter solved it. Guessing I stirred up some debris in the tank when changing the pump that ultimately clogged the filter. Good luck. Link to comment Share on other sites More sharing options...
Swampy Posted April 10, 2019 Author Share Posted April 10, 2019 20 hours ago, gogmorgo said: Been there. The adapter kit that came with my Delphi pump was junk, so it ended up pulling fuel out of the middle of the tank, meaning I "ran out" of gas at around 1/3 tank remaining. I once coasted to a stop about 200 feet from my driveway, had to siphon a gallon out of another vehicle to get the MJ started and into the driveway, then the next morning I had to siphon again and hope I made it to the gas station five miles away, and then only squeezed about 17 gallons into the 23gal tank. I put in 5 gallons thinking my sending unit wasn't registering... still no luck 13 hours ago, kryptronic said: I had a similar issue with my 91. Changing the fuel filter solved it. Guessing I stirred up some debris in the tank when changing the pump that ultimately clogged the filter. Good luck. I plan on ordering a new fuel pump and filter. I disconnected the fuel line that comes from the tank to the filter and tried cranking the jeep and no fuel what so ever came out Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 10, 2019 Share Posted April 10, 2019 29 minutes ago, Swampy said: I put in 5 gallons thinking my sending unit wasn't registering... still no luck I plan on ordering a new fuel pump and filter. I disconnected the fuel line that comes from the tank to the filter and tried cranking the jeep and no fuel what so ever came out Check your fuel pump relay. And your ground behind the driver's tail lamp. Link to comment Share on other sites More sharing options...
Swampy Posted April 12, 2019 Author Share Posted April 12, 2019 On 4/9/2019 at 10:24 PM, Jeep Driver said: Check your fuel pump relay. And your ground behind the driver's tail lamp. I cleaned the ground behind the taillight I'm going to order a new relay Link to comment Share on other sites More sharing options...
Pete M Posted April 12, 2019 Share Posted April 12, 2019 the ground runs through a connector behind the rear tire. It's not as common an issue as the taillight but it's possible to get corrosion inside (lost my brake lights from that) Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 12, 2019 Share Posted April 12, 2019 Did the gauge move when you added fuel? Link to comment Share on other sites More sharing options...
Swampy Posted April 12, 2019 Author Share Posted April 12, 2019 8 hours ago, DirtyComanche said: Did the gauge move when you added fuel? Yep it went from 1/2 tank to 3/4 tank Link to comment Share on other sites More sharing options...
kryptronic Posted April 12, 2019 Share Posted April 12, 2019 Do you hear the fuel pump prime when you put the key in and turn it? Do you have fuel pressure at the fuel rail? Is it the right amount of pressure with vacuum connected and disconnected? Did you check the ballast resistor, and/or attempt to bypass it to rule that out as a problem? Did you replace or swap in a known working relay yet? Did you replace your fuel filter? I had a weird issue with my 91. First my 230k mile old original fuel pump went on the fritz and would randomly die. Oddly, if I dumped what fuel remained in the fuel rail it would start right up. I replaced the pump with the Bosch and all was good for about 2 months, then it died again. This time it was different, though, as I could not hear the fuel pump priming and the fuel rail was always empty when I checked it. Replaced the fuel filter (the only component I didn't check) and it's been good ever since. My theory is that replacing the fuel pump stirred up debirs in the tank which clogged the filter. I think the pump wasn't priming because the fuel was at pressure between the pump and filter, just couldn't get past it. I'm an HO guy, so I'm not sure if I can be of any help beyond asking some basic questions to make sure you checked everything you could. Renix owners might want to chime in. We've got to get Wendy back on the road. Link to comment Share on other sites More sharing options...
Ωhm Posted April 13, 2019 Share Posted April 13, 2019 Check Fuel Pump Relay Block for voltage. Remove FP relay and check the following harness pins: C216_1 (30) Hot at all times. C216_5 (86) Hot with KEY ON or CRANKING. Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 13, 2019 Share Posted April 13, 2019 54 minutes ago, Ωhm said: Check Fuel Pump Relay Block for voltage. Remove FP relay and check the following harness pins: C216_1 (30) Hot at all times. C216_5 (86) Hot with KEY ON or CRANKING. He's got a 2.5. Pump will only get power for 2-3 seconds with key on........will not get power again until start. Link to comment Share on other sites More sharing options...
Ωhm Posted April 13, 2019 Share Posted April 13, 2019 I'm looking for voltage at the Fuel Pump Relay Block without relay. No 2-3 seconds involved here. Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 13, 2019 Share Posted April 13, 2019 86 is trigger from ECU, correct? Link to comment Share on other sites More sharing options...
Ωhm Posted April 13, 2019 Share Posted April 13, 2019 15 minutes ago, Jeep Driver said: 86 is trigger from ECU, correct? True Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 13, 2019 Share Posted April 13, 2019 5 minutes ago, Ωhm said: True ECU triggers relay for 2-3 seconds, prime, then no signal. Unless key moves on to start position. The only reason I bother to mention is because if he turns key to 'on' or ignition.........by the time he walks around to read meter he will show no power at 86.........then think he has ign/power/wiring problem. Link to comment Share on other sites More sharing options...
Ωhm Posted April 13, 2019 Share Posted April 13, 2019 FP Relay is removed for these measurements. Looking for source voltage(s) to FP Relay. Link to comment Share on other sites More sharing options...
Swampy Posted April 20, 2019 Author Share Posted April 20, 2019 Well I got the comanche started today. I swapped the fuel pump relay, Cleaned the connections and swapped in a new fuel filter to be on the same side and after a few primes she fired right up 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