Intermittent Starting Issues

JD210

HHHHHH
Hey Folks I have an o4 deluxe convertible 3.9L. Normally car starts up right away. First issue to happen was when I had gone to neighborhood Walmart not a long trip very short actually. When I started the car to leave I had low Idle at startup sluggish and back fire. Pulled over to restart. A couple times when first trying to restart it sounded like it was try to fire off. Mostly just the starter no firing appeared to be happening. After 10 to 15 minutes of visual inspection under hood and trying to start it my thoughts switched to how I was going to get car back to the house. After about 10 to 15 minutes longer I tried again before calling for help. It started right up. Next day no problems either. Then boom it happened again and again and again. Sometimes it starts right up no problem. Sometimes after engine had been driven sometimes cold. Once it started I had no issues while driving. Not that cold I live in Texas. Called a friend who used to wrench he told me to only change the fuel filter(external). I did and for 3 days it was great. Then same problem started happening again. I now carry a can of carb cleaner to prime it. That doesn't always make it start either. My friend was thumping relays after it wouldn't start after being primed several times. The next try it started. Checking the internet is hit and miss. Most of Google results don't match my car or problem. I don't want to just start throwing money at it. Last week I had to replace alternator and battery Right after changing the fuel filter(changed air filter same time). Check engine codes are P1237 twice in a row then P045. There are so many parts and sensors in the fuel system. I'm hoping I can find out the best sequence to go at this targeting highest probability first and eliminate stuff that wouldn't give intermittent troubles they either work or they don't. I'm dreaming I know. Instead of searching internet I thought I'd try here. I am so fed up with results not even close or related to my search. I try using specific verbaige minimal amount of words but the search engines are there to generate money more than they are to help us. Sorry. Any help would be greatly appreciated. Other helpful info I changed plugs yesterday No effect. I did try pulling spark plug wires off Coil Pack to test had 2 positions did little change to engine and didn't make the popping sound like the others, When tested ohms came up 0.00 all ports. I'm wondering if I have multiple issues and changing the fuel filter was 1 explaining why no problems for 3 days. Also can the testing sequence be prioritized to test that don't require the engine running. Hit me back if you have any questions. hope someones already experienced this and found the solution. Thanks
 
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fasterthanyou

Active Member
Holy moly what a lengthy rant. I'd check fuel pressure when the engine doesn't start. My first assumption is a faulty/failing fuel pump based on the symptoms. Either get a fuel pressure tester or use a scanner to monitor the fuel rail pressure sensor.
 

Serpent

Active Member
probably fuel pump. once they start to go and the fuel level is low, the pump overheats when it is out of the fuel that keeps it cool. then when it stops, it cools down, then works again until it overheats and then on and on. if the tank is full, then doesn't overheat. eventually it will start to fail with a full tank or not and then quit for good.
 
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