1988 duece has me mad! lack of power!

[indymadcaster]

hello,

I need help as i am out of ideas!
my 1988 BII 2.9 gets warm and falls on its butt! never quits just NO power when warm and will not Rev over 2k rpm It has had the following, fuel pump,fuel press reg, filters, injectors, TFI and pickupand reman dist, Dropped the cat converter, New TP sensor and air charge, ECT, new O2 and a Map sensor cap, rotor and wires, ign coil, AND a PCM!!!!

I am a ford tech @ a dealer and the dang thing has all of us stumped,
started out had to drive it 30 -40 min to do this 2 years ago now as soon as it goes from closed loop to open it runs rough and drops power when its in closed loop it runs awesome! goes to warm open loop falls on its butt

any ideas?

 

[rookieshooter]

Did you try spraying some starter fluid around head, manifold after it gets warm? Just wondering if it's a small crack that's opening up after warming up in the manifold or even in the head.
How about taking a compression check while it runs good and then again after it heats up? Leak down test?
How do the spark plugs look, all the same, some greasy, all tan color, are two that are adjacent to each other bad?
Condition of your motor oil? no signs of water/coolant? I'm sure you guys did this one, don't want to sound like I'm talking down to you.
Appreciate the fact that your a Ford tech and mentioned that, some of us would have let our pride get in the way.
There were times when I was an AC technician that I had to ask my compatriot's "what do you guys think"?

Keep us posted on your find.

 

[indymadcaster]

vaccum is 17 17,5 @ idleand @ cruise speeds 20-22
rules out vac leak, checked coolant for combustion residue None, no coolant in oil either and 130 to 140 compresion 27 guys are all @ a loss and look at the truck like its possesed

 

[rookieshooter]

Possessed Hmm, time to call in backup and perform an Exorcism

Any chances the truck's name is Christine is there ha ha.

 

[janderson4010]

I had this exact problem that was getting progressivley worse as time went. I swapped a 4.0 in before it got that bad, but i really had no idea what it was and dont to this day, i suspected something was wrong with the timing, but the 2.9 is gone so i dont have to worry to much. Id be really interested to know what the prob is if you find out.

 

[CougarSE]

Do you maybe have your open and closed loop scenario's reversed? The car would start and be in open loop while cold and when warm would go to closed loop. If infact your truck runs fine while not referencing the O2 sensor then that would be a pretty good indication that something is wrong with the O2 sensor or its wiring. Since you have changed the O2 sensor I would check the wire back to the EEC. Check for continuity from the 60 pin and the O2 sensor plug, but also check for continuity from that wire to body steel. Also check the O2 sensor ground wire, the orange wire on the back of the head.

I say this because years ago I had an 87 ranger with a 2.9 and it ran like a banshee, the truck started to suffer from issues like you describe. After checking the wiring I found that when I had removed the transmission I pinched the O2 wire when I reinstalled it. After repairing it the problem was solved.


I have also not seen any mention of KOEO or KOER ??

 

[4x4junkie]

I have also not seen any mention of KOEO or KOER ??

What I was gonna mention...

You have tried pulling the codes from the PCM, right? Seems anything to do with a sensor or it's wiring to cause it to run that poorly should set some codes I'm thinking.

 

[broncobra22]

Similar problem

1987 B2 couldn't get out of it's own way ... this started being a problem right after I sold it to a local fellow & he went through several shops who tried many of the same things youv'e done...he was very persistant and worked on it almost two years. I bought it back & an ex Ford mechanic and I got it running and it's still running strong, more than a year latter. Bad computer ribbon cable, didn't look damaged but problem area was right at the firewall. Might sound impossible but that's all we did. I've since sold it but it's still in the area.
He didn't check the codes just went straight to the problem and fixed it, said he had seen it before.

 

[janderson4010]

now that i read through this i remember my 02 sensor plug was all melted when i pulled the 2.9, never know now if that was for sure the prob but based on what you guys are saying sounds likely