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Bought a new 1993 f150, automatic, dual fuel tanks, 4.9L, 6 cylinder and now have 350,000 miles. Before Thursday last week the engine would always start in 2 or seconds but now it takes about 10 seconds. Replaced fuel filter seeing no dirty gas in it. Installed a fuel pressure gauge on fuel rail having a constant 50 psi with engine running or off (not bleeding down). Using a Fluke 75 meter checked battery with engine off (12.7 volts), with engine running battery is 14.6, no voltage drop from positive & negative battery posts to starter, no voltage drop across starter relay, auto parts store also placed their tester on the battery posts while starting/running finding no issues & said starting amps is normal. No check engine light comes on. The truck runs very smooth at any speed.
Is this something to be concern about or should have dealer check it out?
Thank you
I would think it will go into a no start after a while.
It sounds like may you have capacitors starting to go bad and after a few seconds they are healing themselves and then the clock in the computer starts to run. But they will not do this very long before the no start and when it does not start anymore the selected fuel pump will run all the time the key is on. When the fuel pumps quit running the engine will start then.
This is a common issue with the PCM Computer when the truck gets to this age.
Have check to see if you have any codes in KOEO or CM yet?
If you have 111,111-1-111,111 then run the KOER test.
Thank you Bill for this information. My day off from work is Friday and will take to the Ford Dealer having it checked. Hopefully the truck will start faithfully until then.
If it is the PCM Computer you may not have any codes or you may be unable to check the codes until the fuel pumps stop running with the key on if that is the case.
I only said to check out the codes as there is a possibility that it may be something else and the codes may point to the problem. If you have the place you take it to read the codes get the number of the code and if the code is KOEO, CM or KOER.
You can also ground the STI wire under the hood and turn on the key and the MIL (CEL) will flash out the codes or you can get a code reader at most auto part stores that will read the OBD-1 codes. Just do not buy one that just has a LED and a beeper as you already have that much in your cluster without the beeper.
With the engine cold I placed a Fluke amp-probe on the cable from the positive battery post to the starter. With the meter set to inrush I started the engine reading 430 amps. Is this normal?
When the engine is cold it takes about 10 seconds of cranking before it starts and will start faster when the truck is up to temperature. The Fluke amp probe I used to check starting amps is for electrician use and may not be suited for automotive work (the dc current feature).