Help '95 aero star wont start fuel pump not running,

Help 1995 Ford areostar 3.0L auto trans. wont start fuel pump not running, Engine turns over fine. Have changed fuel pump relay. Checked roll over inertia switch, (checks good), reseated numerous connectors starting at fuel tank main harness forward. Have installed separate electronic fuel pump into fuel line to pressure up system, engine still wont start as fuel injectors do not seem to be activated. I have Electrical and vacuum manual on hand but dont know where to look

Thanks in advance for any help.

Reply to
Greyhoundollie
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Does the "Check Engine" light come on going from OFF to RUN? It might be a bad "EEC Power Relay". The following is my SWAG (Simple/Silly WILDly ASSuming GUESS).

Switch your display to a "Fixed Pitch Font", follow along in your EVTM, and excuse the poor attempt at ascii art:

+12v-ig.sw.-EEC-P-R(coil)------------Ground. +12v--------EEC-P-R(contacts)-+---ECA Main Power (aka +VPWR-Vehicle Power) | +---F-P-R(coil)----pin22(FP on the ECA) +12v---------------------------F-P-R contacts--inertia sw---Fuel pump--ground.

The above is based on a "typical" Ford with discrete relays and only one (in tank) fuel pump.

When 12 volts is applied to the EEC Power Relay's(EEC-P-R) coil, and the other side of that coil is to the vehicle's ground, and that ground is good all the way to the negative battery terminal, the switch contacts "make" (switch is ON) and 12 volts is supplied to both the Fuel Pump Relay's (F-P-R) coil and to the ECA. The other side of the relay's coil is wired to pin 22 of the ECA. The ECA is a computer and "boots up". Part of this boot up sequence is to drive the transistor at pin 22 (designated "FP" Fuel Pump) into conduction for a short time (I call it two seconds). If the ECA isn't powered up (maybe there's no +12 volts from the ignition switch, maybe there's no +12 volts to the ignition switch, maybe the EEC Power Relay is bad) then pin 22 isn't going to be driven into conduction to allow current through the Fuel Pump Relay's coil. Of course, without the ECA, your injectors won't get pulsed. You may have spark, as a TFI ignition will work with just PIP and power. To verify that, spray a fuel injector cleaner past the throttle plate and see if it kicks while someone cranks it. Don't go overboard with the stuff, you're not trying to "run" off the stuff, just verifying you got power to the ignition components. Unfortunately (this is a "damnit guys, give us a break" issue), while th EEC Power Relay and the Fuel Pump relay are functionally identical, Ford put different base keys on them, so you can't interchange them. Anyhow, I hope it helps out a little better in figuring out what to look for, particularly since this is probably a "power" issue.

Reply to
BillyBBad

Thanks for the reply,

Raining out at the moment so will check later. I did check yesterday to see if there is some ignition. (sprinkled some gasoline on air filter and cranked engine. Yes it did fire a few times. So Ignition is probably not the culprit here.

Reply to
Greyhoundollie

Hi,

Thanks for the help so far. I have really been strapped withthe christmass/new years holidays as I am sure you have. I did discover the following:

I can get the fuel pump to run when shorting to ground thpin on the Diagnostic plug (ONLY IF the ecm connector is disconnected).

I purchased a new (USED) ecm and the problem did change. the fuel pump will work more or less correctly now with new computer..........fuel pump pressures up when key turned on. Then does not pump after about 2 seconds. So i think this is about normal operation. I did "Purge air" at the fuel rail schrader valve.

However engine still does not start.

Have checked to see that the distributor rotor is indeed turning and I did dribble a little fuel onto the air filter to see if the engine tries to fire. I does so i think the ignition part is ok. I guess it is probably more likely pointing toward somethign controlling the fuel injectors.

any help in this area would be appreciated

Thanks

Richard

Reply to
Greyhoundollie

In the owners manual for my '9 Aerostar van is something about a safety fuel pump shutoff, that will be activated in a collision, or even a pretty good bump might activate it. It said it had to be manually re-set. In the '96 it said it is behind the panel on the right side just in front of the door on passenger side. (Inside the van)

Reply to
oldfogie

Go to parts store and get a "'noid" which is a test light for injectors.

The collision cutout is obviously not tripped since you get FP on with ignition

have a helper check to see if FP runs more than two seconds while cranking. or hook 12v test light to the FP pin on diagnostic plug

This would show that the ecm is seeing the dist pulse, as it turns on FP relay with pulse.

If FP is not running while crank then problem would be TFI, ecm or wiring

oldfogie opined in news:tEaEd.10418$ snipped-for-privacy@bignews5.bellsouth.net:

Reply to
Backyard Mechanic

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