No power to fuel pump

Tiny
ALEXANDER3002LA
  • MEMBER
  • 1990 CHRYSLER LE BARON
So I changed the fuel pump before I tested it. The old one worked but I cannot return the new one. After testing both fuel pumps I realized that there is no power going to the fuel pump. What can I do? Is this common for this car?
Wednesday, May 5th, 2010 AT 1:39 PM

24 Replies

Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
It sounds like the fuel pump relay is not working. Here is a guide to help you test it and the location of the relay below:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

Cheers
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Wednesday, May 5th, 2010 AT 6:40 PM
Tiny
ALEXANDER3002LA
  • MEMBER
  • 2 POSTS
  • 1990 CHRYSLER LE BARON
Six cylinder front wheel drive automatic.

I replaced the fuel pump in my car and the new one is not sending gas to the engine. The engine will not turn over.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
INTERNETMECHANIC
  • MECHANIC
  • 700 POSTS
Because I do not know testing you have done, I have to start from scratch. If the vehicle cranks good but will not start, have a helper crank it, while you visually check for spark at the plugs. Check for possible trouble codes, if you have not already. To check for mil codes, you turn the key just till the dash lights come, no further, cycle the key on--off, on--off, on, then the mil starts flashing, you count the flashes to get the codes. Your looking for two digit codes. The information I looked at was Lebaron--3.0 sedan. The ASD relay sends voltage to several circuits including the fuel pump. Did you check voltage and ground for the fuel pump motor at the pump connector? The voltage wire for the pump shows to be dark green with black tracer.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
STEPCHILD
  • MEMBER
  • 6 POSTS
  • 1992 CHRYSLER LE BARON
Six cylinder front wheel drive automatic.

For the past three to four weeks my car has been giving me fits. When I turn the ignition key, I will normally hear the fuel pump prime. It now only works randomly. I have replaced the fuel pump relay and the pump itself (boy, that was fun), but still no joy. When I turn on the ignition and hear the pump, it will start. But, all too often, I do not get that beautiful hum that will allow me to go where I need to go. Any help?
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Start by testing the ignition switch and the ASD relay.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
STEPCHILD
  • MEMBER
  • 6 POSTS
Thanks for the quick response.

Where would I find the shutdown relay? I cannot seem to find it in any literature I have on the car. And, everything else functions normally when the key is in the start position, is there a direct link from the switch to the fuel system relay?

Thinking there may be a bad or corroded connection at the fuel relay, I sprayed a little WD-40 on the relay and the relay/fuse block, which helped, but did not fix it. I am going to remove the relay block and check for rusted or corroded connections.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
STEPCHILD
  • MEMBER
  • 6 POSTS
I checked the relay block and the ECU connections as well, all looks good. What are the chances that the engine control unit itself is bad?

One more observation, it seems to start best in the morning and evening when it is cool. Springtime here in VA.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The ASD relay is in the engine bay forward of left strut tower. See picture below. I do not know about the computer yet. Check basics before you go there.


https://www.2carpros.com/forum/automotive_pictures/12900_asd_5.jpg

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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
STEPCHILD
  • MEMBER
  • 6 POSTS
Although the picture is not representative of my particular model, (1992 convertible) I did find the ASD relay and checked it with multi-meter. Seems to be functioning fine. Any other suggestions? By the way, I really do appreciate the help.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
What kind of reading did you get from the ASD relay?
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
FISHES8
  • MEMBER
  • 3 POSTS
  • 1989 CHRYSLER LE BARON
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 12,000 MILES
I ran out of gas on the way to get fuel. I put a few gallons in and it registers eighth full. Car still will not start. I can hear the fuel pump. I checked I have fuel pressure in the fuel rails (I do not know the exact pressure). I did not get spark at the plugs, so I checked the coil. No spark at the coil. I suspect I may have blown an inline fuse someplace but I cannot figure out where it is. I have Chrysler repair manuals, but ironically I cannot find anything about fuses.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
JAMES W.
  • MECHANIC
  • 2,394 POSTS
Running out of gas will have nothing to do with losing spark. With the key on, do you have power to the positive side of the coil?
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
STEPCHILD
  • MEMBER
  • 6 POSTS
I do not know how they are numbered, but the pin that is flat compared to the others, had 0 volts in the off position and 13.8 with ignition on.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
FISHES8
  • MEMBER
  • 3 POSTS
It is entirely possible that the car developed some electrical anomaly at the very moment my car was on vapors. During my web searches (before I narrowed it to spark) I did happen across a forum post (another site) that said it is possible that a relay, fuse, etc. May have been tripped because of the extra draw from the fuel pump running dry.

The other thing I learned from all of this was that many fuel pumps are cooled by the fuel, so never let it run dry or you might be looking at replacing the fuel pump! Okay, so lets forget that I ran out of fuel. I am trying to find out what could cause no spark from the coil (assuming the coil is good).
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
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Have the computer control of the ASD relay tested.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
JAMES W.
  • MECHANIC
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It is true, fuel pumps are cooled by the fuel in the tank. GM and Chrysler are not noted for burning out a pump on an empty tank, but Ford is notorious for it. We cannot "assume" the coil is good, we need to know. With key on check for power on the positive side of the coil. If yes, check for positive voltage on the negative side. If no, the coil is bad. Next you need to check for injector pulse. This can be done with an "incandescent" test light connected between both terminals of a disconnected injector connector and cranking the engine. You are looking for the light to blink. If no blink, it is either the crankshaft position sensor or the ECM. The coil and injectors get the signal to fire from the ECM and the CPS.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
STEPCHILD
  • MEMBER
  • 6 POSTS
Turns out the ECM has a physical crack. Replaced the module and all is well. I have my little red mid-life crisis back to par. Thanks for the help.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
FISHES8
  • MEMBER
  • 3 POSTS
I replaced the coil because it was only $20.00 and it had some corrosion. I also replaced the ignition relay on a whim because I thought it might have been related to the automatic shutdown (ASD). It also was cheaper that a new ECM. I tried testing for pulse with a multi-meter. It just went from 9 volts to 6 volts during cranking. The book said it should wiggle back and forth. Is a test light more accurate?

What is the crankshaft position sensor?
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
JAMES W.
  • MECHANIC
  • 2,394 POSTS
Yes, an "incandescent" test light or an analog volt meter works the best. If you are using a digital meter, it will not respond quickly enough. The "wiggle back and forth" is the needle on an analog meter. The crank shaft position sensor, CPS, tells the ECM when to fire the plugs and the fuel injectors. Also, there is a unit called a "noid light" that is a small zenon bulb that plugs directly into the injector connector and flashes like a timing light. You can get a complete set at most parts stores for about $20.00.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)
Tiny
BOOSTING16PSI
  • MEMBER
  • 2 POSTS
  • 1992 CHRYSLER LE BARON
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 160,000 MILES
V6 3.0 Convertible. Battery cables are corroded green with white powder. Need to replace complete positive and negative cables, can they be special ordered? Now not getting power to fuel pump. Would bad battery cables stop just the fuel pump from getting power? Thanks a lot.
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Thursday, July 19th, 2018 AT 12:48 PM (Merged)

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