Lack of power after new heads

procadman · #1 09-27-2012, 10:00 PM

Issue 1:
'89 2.9 with about 40k on bottom end and less than 2k on top end.*1

It was totaled last year. I have driven it about 500 miles since the frame was straightened.

After replacing some salvage panels with new ones and general buttoning up of things, it decided not to start.

When the key is turned on and fuel should be pumping and pressurizing the system nothing happens.

There is a breakdown in power or signal between the fuel pump and it's relay. The fuel pump, only 1,5 years old, works perfectly well when voltage is applied directly to it and a new relay makes no difference. I jumpered the relay connector and the inertia switch connector, just to double check, and this yielded no positive results.

The wiring diagram shows only the fuel pump, the inertia switch and the fuel pump relay, in that order. Otherwise it shows signal coming from the ECM unit.

Other posts have pointed to a faulty EEC relay. Mine checks out.

I ran power directly to fuel pump which ran but engine still fails to start.

Issue 2
Prior to the fuel pump issue I had put everything back together after the last issue with the heads and drove it for roughly 1000 miles in mixed conditions.
Started fine, ran smooth and seemed to have plenty of power around town. To date I have not attempted to tow anything heavy which use to be routine.
On the expressway, past 55 or so, it had practically nothing left. Past 70 is like stepping in a hole. Lack of power is most evident when it would not stay in cruise while in overdrive, except on the flattest of pavements.
Also, as you might imagine, it is sucking gas like there's no tomorrow. It was never thrifty, due to the towing package, but now gets between 10 and 15mpg.
Compression in all cylinders is within norms.

Since I can't see this issue at normal driving speeds I have been tempted to pay for a Dyno test so a possible cause might be found at the speeds where the problem arises.

Also, my local Ford dealer has lots of issues diagnosing something on a vehicle over 5 years old.*2

*1) Blew a head gasket at 73k and Ford put a long block in (100k mile bumper to bumper warranty.)
2.9 heads cast around '89 and later, though cast iron. exhibit issues once they have 70k+ miles on them.
The original castings were poorly made causing the valves to receded into the heads and/or heads to warp just enough to blow into water jacket or across cylinders.
I have had all 3 conditions on 3 separate sets of heads. The last time it happened I was able to find new recently cast heads and, hopefully, will not have this issue again.
If I had not just rebuilt the tranny (Auto w/overdrive) I would have dropped
something more substantial in the 2.9s place.

*2) I had a bad vibration when I got the truck back together. They said it was the carrier bearing. I disagreed but replaced it anyway. The old one, not oem, was fine. Turns out new rear tires I had just bought were out of round and the Ranger is sensitive to that factor. BTW, They wanted $300 to replace the carrier bearing.

Psychopete · #2 09-28-2012, 03:15 PM

So is the immediate problem the no start? The lack of power you shouldn't worry about until you can get it running again. Are you getting any spark? Even through the ECC relay checks out, it's possible for other parts of the circuit to be broken - like a ground - I know the Gen-Is have a ground wire from the battery that runs into the main harness to the ECC, and you'll have problems like you describe if it get disconnected, but I am not sure if they used that in the Gen-IIs. They did a lot of things differently in '89, added a power distribution box instead of lineline fuse links.. Check for any signs of life from the computer, like seeing if it will at least run the self tests and control ignition timing.

There's a fuel pump test on the diagnostic connector that you can override the computer control over the fuel pump relay that might be some help.

procadman · #3 09-29-2012, 05:15 PM

Good point.
I have no spark either.
So far have checked resistance across coil terminals, coil wire and am proceeding to check if distributor is turning.
As you know it is in almost the worst place for having access to it.
Will keep you posted.

Psychopete · #4 09-29-2012, 06:42 PM

do you remember if you had fused power to the ecc relay - that would rule out a blown fuse or wiring problem there, relay would still be OK. visual inspection around the computer, check for moisture. the cowls like to rust through and leak water on the computer. =/

procadman · #5 09-30-2012, 03:17 PM

Good thought but no rust.
There is no rust through any body part with the exception of the top of the bed panel where every one of them of that year rusts.
The only exterior rust is where my daughter backed into something above the bumper and below the taillight. Pushed the body in and broke the paint.

All Power fuses, in the power block, and all inside fuses in the panel show continuity.

Going out now to look at distributor. More and more this is pointing to the ECM: No fuel signal, No spark, no reason why.

procadman · #6 10-02-2012, 01:57 AM

Distributor checks out, at least mechanically. It's module may be faulty but that shouldn't explain the lack of signal to the fuel pump.
Either these are related somehow or a huge coincidence.
The only item the fuel pump and spark control share appears to be the ECM.

I'm going to rent an analyzer to see if I can get closer to the issue.
(I have an inexpensive code reader but it doesn't appear to fit this model)

Psychopete · #7 10-02-2012, 07:12 AM

Check out pulling Ford EEC-IV OBD-I codes manually on You Tube, there are a lot of videos on how do this manually with out a scanner. Even better if the check engine light isn't burnt out, they blink out there, otherwise you have to add a couple wires in the mix for a test light or analog meter.

procadman · #8 10-03-2012, 03:44 AM

Thx,

I'll try that.
(Pulled a muscle or bruised a rib and wasn't able to work on it anyway ;-) )