95 Town Car cranks but no start [FIXED]

Hello again. This time I have a 95 Lincoln Town Car Cartier with the 4.6 motor and 46k and a intermittent starting issue. Sometimes when I try and start the car it will crank over. Usually when I turn the key to the on position I will hear the fuel pump prime up. It seems when the battery is a little low, it won't prime when I turn the key on and this is of course when I just get it to crank and no start. I can attach a fully charged jump box to the battery and I will get the fuel pump prime with the key on and the car will start. I check the battery voltage and when I get the no start/crank and it is around 11.4 to 11.8. My question is does the fuel pump need the full 12 volts to get it to prime or is something else at play. Or possibly that 22 year old fuel pump is on it's way out?

My guess would be the 22 year-old pump. Can you do a current waveform of the pump?

Thanks for the reply. Unfortunately, have no way to check the waveform. However, I did fully charge the battery and checked voltage and it was at 12.2 volts. I did have to cycle the key on and off twice to get the pump to prime. The car started right up after. The voltage with the car running was 12.4 once the idle re learned itself.

from sounds of symptoms youre going to need a new battery or clean connections really well then recharge if newer battery and new fuel pump // im having similar probs with my 1996 ford f150 ive been a diyer for over 40 years

Hey Slimmer71! I'd be interested to know if the check engine light comes on when you get a lack of prime with the key on. It kinda sounds like the PCM isn't getting powered up (and therefore isn't running the pump prime), but raising the system voltage brings it to life. 11V in the battery is definitely low, but it should still be enough to get a prime out of the pump.

The system voltage with the engine idling is 12.4V? :huh: That's a possible indication of a weak charging system. The battery only reaching 12.2V after charging is concerning, too. It might be best to address the battery and charging system first before going into your fuel pump issue.

Here's a quick shot of the charging system diagram:



A quick and easy check of the alternator and cables would be to verify battery voltage at the main battery post on the alternator, and a voltage reading at the case of the alternator. The main battery post voltage should be pretty much the same as at the battery, and the case should show 0V.

No check engine light at all. I had the battery and alternator tested and the alternator is good but the battery checked bad. The voltage dropped when placed under load. That battery was about 3 years old but the car sits alot and gets started maybe once every 3 months or so. I am thinking that did it in. I bought a new battery and have been driving the car for a few days and the car starts everytime now.

technically your car should be sttarterd and brought up to full operating temp once a week to keep tjhe gaskets soft and pliable water flowing so doesnt build up trash in bottom of radiator ans so many more things