QuestionQUESTION: Hi Roland, here's my problem; My 86 Chrysler LeBaron 2.5L FI has a problem not staying running after about 5 minutes of warming up. We have replaced the fuel pump, rubber fuel lines, vacuum hoses, injector, regulator, pump "sock",and filter. We enjoyed the car as a daily commuter car for about a year, then parked the car for about two to three months. I decided to start driving it, so I retagged the car and have not got it to run right since. It won't start but every once in a while, and when it does, same old, same old. I read in my Haynes repair manual that the fuel cut-off relay is located on the inner fender @ the battery, but the only relays there are the starter, fan and AC. The manual states that it is located @ the map sensor, but mine is located behind the kick panel on the passengers side. There is not a relay located in there, unless I just plain can't see it. I've never worked on cars for a living, but I've done the majority of work on my own since I started driving 27 years and some 60 odd vehicles later. I want to test this relay and would appreciate your wisdom on this matter. I am a Mopar fanatic, but my patience is wearing thin on this particular automobile. Thank you very much in advance for your help. Jeff.
ANSWER: Hi Jeff,
There is no separate fuel pump relay. Rather the power module in the engine compartment has that function (along with the spark coil power, so this is basically a built in 'autoshutdown' relay function) in it It is a dark green/black trace wire on pin 6 of the 10-pin plug at that module. It should show 12v when cranking the engine over and when the engine is running.
I wonder if you might not have some other problem such as a hall effect sensor in the distributor that is failing as it warms up.
There should be a self-diagnostic capability in the logic module. Turn the key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the check engine light to see it begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat the process to assure an accurate set of flash counts. Let me know the counts in order of appearance and we'll go from there.
Roland
PS Please 'rate' my answer, and where you see the question about volunteer of the month please consider a 'yes' answer. Thank you.
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QUESTION: Roland, "26" was the code I received when I performed the diagnostic test. I'm finding it interesting that the car might or might not start for days at a time. It looks like it would restart after sitting all night or at least after a couple of days. It hasn't restarted since Saturday. I can pour gas and or starting fluid in the throttlebody and it will start for the time it takes to burn off the fuel. It runs fine for the time that it is warming up, but then... well you know the drill by now. Thank you for your patience.
ANSWER: Hi Jeff,
The 26 code points to the fuel injector circuit not drawing the expected current which could mean the injector winding is open or the wiring from the logic mudule to it is flaky. You could pull the injector plug at the throttle body and measure the resistance which should be around 1 ohm.
Let me know if that looks correct and I can tell you the balance of the wiring. Let me know if this is an H-body GTS or a K-body Sedan.
Roland
PS Please 'rate' my answer, and where you see the question about volunteer of the month please consider a 'yes' answer. Thank you.
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QUESTION: Hi Roland, sorry for not getting back sooner, but the weather has been less than favorable. I checked the ohms of the plug on the fuel injector and it was around .58-.7. It may have been my unsteadiness that resulted in the small fluctuation. Anyway, I went back to the tank to test voltage to the pump while cranking the engine. It was getting 12 volts to the pump, but when I would plug it back in, I didn't hear or feel the pump working while being started. I just wonder if that 14 month old fuel pump has quit working. If so, is it possible that that could be an intermittent problem, or am I incorrect? I have someone looking to purchase the car from me, so I want to sell them a good car. I'd like to fix it so as it was working properly when they took delivery. Once again, I'd like to say thank you for all your input in helping me with this ongoing problem. I'm an old school, carburetor kind of man that has very limited knowledge on fuel injection. Looking forward to your advice!
AnswerHi Jeff,
In light of your comment, let me suggest that although the resistance of the injector is in the range of expected, and because you have verified power to the pump, if you also hear the pump when the key is first turned to 'run' for a second we have to assume the pump is good. So then start the engine which you say you can do, and then take a look at the spray pattern of fuel at the throttle body. Then when the engine dies after a few minutes look at the spray pattern again while you are cranking it over. If the spray pattern is missing or abnormal(asymetrical/drippy/after-drip when turn off key) AND the fuel pump runs for that 1 second test, then the fuel injector is going bad during usage. A well-functioning 25 year old fuel injector is pretty rare.
Roland
PS Thanks too for the nomination.
Hi Jeff,
The fuel pump should run for about 1 second when you turn the key from off to run, at least that was true in the late '87 models and -on when there was a separate ASD relay used. So check the power to the pump when you turn the key to run and if indeed the power is there for about a second, then for that second you would also hear it hum. If it does that, then I would be nearly certain that if the pump gets 12v while cranking then it would also be humming though you can't hear it over the sound of the starter motor or maybe even when the engine is running. It is seldom an intermittent behavior.
Roland
PS Please 'rate' this answer and consider a 'yes' for the nomination question. Thanks
