Intermitent Starts

[dwb3937dwb]

Ive have 1996 ford Taurus that likes to start sometimes will run for days and then just quit. To get it to restart i have to disconnect the battery and unplug the ECM and let it sit for 25-20 minutes. then it starts and runs. But trying to restart right away will not work. im getting spark and can hear the relays click during with the key turned on but not start mode. could the constant control module be effecting the fuel pump? I have replaced the fuel pump (less than 6 months ago) and have also replaced the ECM (in the firewall) Im not blowing fuses. does anyone have a way to test this with out purchasing a new CCRM (next the battery) Grounds all look good but unsure how to test. any help from the pros is greatly appreciated. This one has stumped me and i need to get O'l reliable, well reliable again. thank you Dave

if anyone has the pinout diagram for this CCRM and or a shcematic of the board and which relays do what this would be a great help.

[shorod]

Welcome to the forum!

Have you ever tried just letting the car sit for 30 minutes or so without disconnecting the battery? If the fuel pump is weak and overheats, it may work again after it's cooled.

I can send you a PDF of the CCRM pinout. You'll want to check both the inputs and the outputs before condemning the CCRM. Have you checked for fuel pressure and spark when the car won't start? You might do that before going much further. If you learn you don't have spark, the CCRM is probably not the issue. It would be more likely at that point that the problem is with the CKP or the CPS sensors.

-Rod

[dwb3937dwb]

Originally Posted by shorod

Welcome to the forum!

Have you ever tried just letting the car sit for 30 minutes or so without disconnecting the battery? If the fuel pump is weak and overheats, it may work again after it's cooled.

I can send you a PDF of the CCRM pinout. You'll want to check both the inputs and the outputs before condemning the CCRM. Have you checked for fuel pressure and spark when the car won't start? You might do that before going much further. If you learn you don't have spark, the CCRM is probably not the issue. It would be more likely at that point that the problem is with the CKP or the CPS sensors.

-Rod

Thank you Rod for your reply. I checked the following.
Spark is in good shape all cylinders.
No fuel pressure due to the pump not running. I have let it for over 30 minutes and them some with still no start. The pump in there now is less than 7 months old. I've checked the cutoff switch connector unplugged in the trunk with key on voltage of initial of 11.5 volt then drops to 6.4v. 12v with key in start position I've also checked the the continuity of the switch itself and is good in good shape. I checked the wire harness at the tank and fuel filter area and it is getting the same voltage. The all black and black and pink wire are pump voltage feeds for anyone else that's following. So I pulled the tank. pulled it to the side of the vehicle of the fuel filter and plugged it back in the main harness still no joy. I pulled the pump assembly out. I disconnected the pump leads and pulled the pump from the pump housing assembly and put a test set of leads on the pump which does have a + and - on the head of the pump and tested direct to the batteries plus and minus terminals. "Houston we have ignition" . So the pump runs not very long because as you stated is not to meant to run dry. So at this point I'm thinking ok I've got power at the harness up to the to the pump harness its got to be in the fuel pump wire harness from the pump to the main wire harness. I did a continuity check here on the pink and black wire and the all black wire that comes from the pump had good continuity on the black but the pink and black showed nothing. I wiggled the wire in different spots and found two spots that i could create continuity by bending the wire in various directions. I replaced the pink/blk wire with a full length of new wire same gauge 16g and reinstalled pump and assembly into tank i did also test before putting the tank back in and it work. reinstalled the tank all hoses and filled with 10 gal of gas and hit the start switch and could hear the pump engaged and then.....varoom....its running again. Sorry to go so long on this thread but thought that it may be helpful for others remember check your connectors check your voltages and check your continuity. will update if I have any issues later on. Thanks again for your reply. Rod would you send me the pinouts for the ccrm please thank you
Dave

[shorod]

Thanks for posting your findings. Glad to hear that you have it fixed after finding the breaks in the wires.

If you send me a Private Message with an e-mail address for you, I will send you the pinout for the CCRM.

-Rod