1989 Ford Crown Victoria LX 4 Dr - 302 Eng, PS, PB, Air.

I started a thread on this problem back in November of 2018 (I think). Then, thinking I was still 18, jumped off the tailgate of my F150, the action of which spun me around and went into a backwards fall. Hitting the ground, back-wise, full force, and liking to knocking my brains out plus a rehashing of a cancer thing, this thread was put on hold & restarted here... hope that's okay. Originally thought I had a fuel pump problem, but since then have rethought that.
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Engine starts easily after a couple revolutions like always and runs smoothly but only for a few seconds after which it begins to run rough and die out. To simply turn the key to the start position again has the engine restarting immediately once again but only to die out again.

Playing with the gas pedal, causing a continuous rpm increase/decrease continuation, I can keep the engine running but it is really a rough running engine... actually feels and sounds like it running out of time. Eventually, after a few (4-5) minutes of this up/down rpm action, the engine continues to run (but rough) while holding the pedal still... and I can lower the rpms gradually to its idle setting where it seems to smooth out.

Shifting into gear, just starting to move, it still feels like it's running rough, but as a short time passes, and at a normal driving speed of 40 mph or so, the engine feels normal, smooth, no vibration... highway driving, pulling into a Wal*Mart or Post Office parking lot to park... the engine acts normally in all respects.

However, shutting the engine down for a store visit or whatever, a cooling off engine-wise of about perhaps10 or 15 minutes, the rough running engine starting routine is present once again but takes much less time to get it smoothed out.

Myself, being a mechanic, but in the marine line (boats/engines, etc), I'm inclined to think that if a fuel pump, which I originally thought was the problem, it would stall and that would be that! How I could drive it around town mystifies me.

 

Hi Joe,
You didn't mention if the fuel filter was ever changed, how do we stand with that?
To help pin down if the fuel system is doing what it should when it should, you might get hold of a fuel press gauge and see what the fuel pressure is when starting and running some. Post the readings here and, if necessary, maybe can offer some other suggestions. It does sound like it might be starving for fuel at times.

Take care.

 

IAC, EGR, unmetered vacuum bleeds as well can greatly affect idle stability. Since the power and drivability seem good at cruise speeds I’d make sure on fuel pressure/volume is spec, and there’s no issues with IAC, and any EGR application at or off idle...

 

Sorry for the delay... cancer bug acting up a bit, but okay.

I went thru all the checks (by the book) of the Fuel Relay, the EEC Power Relay, the in tank Fuel Pump. Everything seems to check out... I say "seems" as obviously I'm overlooking something.

I was really thinking the in tank pump had failed but this morning I hooked up a Fuel Pressure Gauge and the pressure immediately went to 35/40 psi without wavering. Perhaps I've reached a point in life (86) to where I just can't get my head wrapped around these things anymore. At any rate, I'll be putting this 89 Crown Victoria in the local shop to have this problem taken care of. Now, the drivers door lock solenoid... that I can handle!

I do appreciate the helpful advice from you pros there at The Ford Forum... It's been educational and you've saved me a bundle of $$$ over the years with my vehicles. Thank you all so much. (Joe)

 

We have communicated with you so often that you are part of the Ford Forum Family. Keep learning , that's what keep us going. The only thing 86 means is 86 trips around the sun.
Hey Joe, the guys at the shop need to make a living too, so ya gotta give them a little $$$$ once in a while. Stay in touch , always good to hear from you !!

 

Hanky, one last thing... I came across a Internet test instructional w/pictures that show my pump relay in color with the wires numbered 1 thru 4 of which I assume the numbering is constant throughout the industry.

Wires appear to be: 1=Tan W/Green Stripe (Fuel Pump Relay Control)... 2=Red (Power-from EEC Power Relay)... 3=Brown (Fuel Pump Output)... 4=Yellow (Ignition Fused Power - Fuel Pump Fuse)

Test 1 - (Checking for Power - Low Current Circuit) - Multimeter connected between ground and #2 (red wire) to see if 12v is supplied to #2 (red wire) but only when key is ON... Key ON = 12v = Okay... Key OFF = no voltage = Okay

Test 2 - (Checking for Power - High Current Circuit) - Check #4 (yellow wire) that high current circuit has battery voltage when key is ON = Okay... BUT...also 12v present with key OFF.

Test 3 - (Jumping The Fuel Pump Circuit) - Jump #3 (brown wire) to #4 (yellow wire) which should cause the pump in the fuel tank come on = Pump comes on and fuel pressure rises to 35/40psi... BUT... with jumper installed, pump runs with key in either position, ON or OFF.

Test 4 - (Checking That The Computer Is Activating The Fuel Pump Relay) - Alligator clip of Circuit Test Light connected to Bat positive (+). Point of light piercing #1 (tan w/green stripe wire). The test states that the Circuit 12v test light should glow when the engine is cranking... BUT... the test light glows very dimly (Not Brightly as when connected across battery) as soon as I pierce #1 wire... and goes OUT as soon as I turn the key ON... then comes back on dimly again and stays that way as long as I crank the engine... that dim light goes OFF when I turn the key to OFF... BUT... The test light never flashed brightly, just this very dim low voltage appearance. It seems to me that a couple days ago, during this test, the light DID flash brightly. I probably accidentally threw 12v to something I shouldn't have and blew something electronically. Never fails!

Test 5 - (Testing the fuel pump voltage output at the relay) -.Alligator clip of test light clipped to battery negative (-), probing #3 (Brown - Fuel Pump Output) - As key is tuned to ON, Fuel Pressure raises to 40psi. When cranking engine, test light just glows dimly.

Eventually I can get the vehicle to run (after many start/die periods). During one 30 or 45 second run, I paid attention to how the engine and pressure gauge acted, as follows:

The pressure was about 35psi, remaining from running thru the tests... In turning the key to the start position, cranking over and immediately starting, the pressure dropped to 30psi and stayed there for the 20 or 30 second run. The idle was normal, fairly smooth as if all was well. Then after about 20/30 seconds, the engine started to die, acting as if it was simply running out of gas... and as the rpms were dropping the pressure rose to 40psi which completely stumps me... the rpms dropped "before" the pressure changed BUT I expected the pressure to drop, not increase?

So that's my last word on the matter as every time I go thru the test procedures, at the halfway mark, I become pretty well confused. However I wanted to jot all of the above down to see if you made any head or tail comments of what it all might mean.

 

I don't believe you did anything wrong, but you detected a weak signal or connection..At this time I don't have a definite path for you to follow , except if time and conditions permit, I would confirm all my ground connections are good. That signal you observed that was bright one time and not another , I believe comes from the ECA and if it has problems with ground supply /connections it will affect that dim light you observed.

I don't believe we should be concerned with the increase in pressure at the time the engine is getting ready to stall at least not yet. If you have this stalling problem on a regular basis and can't come up with anything definite, I would just connect my meter to a different part of the fuel pump circuit each time and watch for where the voltage drops at the time it is getting ready to stall.You may catch something and maybe not. at least you can rule out what you know is working correctly.

In the early years there were problems with the grounding system in the early ECA s and We don't know if the ECA in your vehicle is the original..

What we usually try to do in a situation like this is connect an 8 channel scope to the various systems and record the time so it can be examined at a later time. When we do that close examination it allows us to observe just what happened first and affected everything up to the stall.

 

Same day as per post/reply #6 above: About two,hours later, I managed to get the car running fairly normal and I took the Crown Victoria out for a spin over to Wal*Mart, then to a restaurant. It ran (after a short rough running warm up period) like all was well.... idle, acceleration, speed, the works, while underway. I was in Wal*Mart about 45 minutes, and re-starting the vehicle is fast... really fires almost instantly, runs at idle normally but goes into a rough running mode within seconds and would die out if I didn't play with the gas pedal. However it smoothed out within 20 or 30 seconds and all was well as I drove to the restaurant.

Leaving the restaurant, starting the vehicle was a repeat of the above, and driving home.... one would think it just came out of the showroom... no problems. Being a mechanic in the marine line for 30+ years and quite serious about it, I know how important good tight clean grounds are so I will try to look up to see what a ECA is and where it's located... could have come loose somewhere in the past 30 years.

 

Hayapower.... I recall getting into the IAC and the EGR on my 1988 F150 some years ago, but had forgotten that episode. I will get back into that service manual and read up on it. I appreciate the reminder.