Ok it was running great since a full engine rebuild, it's got about 11k on it now. Recently I changed the fuel filter again, using a NAPA filter, all was good....put a used Downey open air element kit on it... all was good, added a little more breath at the top end...it pulled great up to 5000 RPM... real nice....

The rig sat for a few weeks while I fiddled w/ the body lift, I lowered it from 1" down to 1/2"... then I took it for a drive and it fell flat on it's face at 3500 RPM, stumbling and sputtering if you try to push past this area, 3600 RPM range...

Anything below this RPM it runs fine, sounds good, doesn't miss, idles nice w/ the 261c, etc.

I checked for possible body-lift-pinched wires & lines and it all looked fine, no lost wires or grounds from what I can tell.

So I switched the AFM and intake back to OEM stock, same result. Changed the coil out for a MSD Blaster I had sitting around, same thing. Put a new Denso fuel pump in for kicks, fixed the fuel gauge w/ a new OEM sender, that works great.!... but it's still falling flat on it's face at 3500 RPM

Seems like it's either fuel or fire, so maybe the fuel pressure regulator.... or ignitor pack...?

 

If you unplug your TPS, does it do the same thing? sounds like a faulty TPS here's a link to check it out!

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

heres ur fix, put the bigger body lift back on loL! but idk ive never heard of anything like that, could it be a pinched vac line?

 

Hm... I put a new TPS on it when the engine was rebuilt, but I can try unplugging it to see what it does.

I think the body lift change was a coincidence with the problem, I could be wrong but I checked all the stuff that could move or be pinched.

It seems like it's something simple... at first I really thought it was the coil.

There has been a code 12 thrown for a while, but idk that's the knock sensor... Not sure what's up w/ that, there were a few bugs that I was working on but it ran pretty damn good amongst a few little things...

 

code 12 knock sensor? are codes different between you and I? i'm thinking rpm signal.
try pick up coil resistance and air-gap check. then those two little wires from dist. to ignitor

 

check lines by the fuel tank?

 

Ok, I gotta look into the codes thing because I have an 87.5 up (square diag box on pass fender), and I guess the early 87 were different codes. Plus I don't think I can count flashing lights correctly.

http://www.pirate4x4.com/forum/showthread.php?t=3969

http://www.22rte-trucks.com/public_f...uble_Codes.pdf


Yep they all looked good when I dropped the tank to do the sending unit and pump.


/

 

ok. ok ok. your getting 12 strait blinks? i was thinking you were on the updated system that would show code 12 as blink, pause, blink,blink

 

Yeap 12 straight blinks then resets for 12 straight blinks again

 

is the cam the original? Or is it a new chinese knock off. Ther have been problems with cheap aftermarket cams losing thier profile and having no power up top. There are a couple threads on hear about it. Try looking for them.

 

No it's an ENGNBLDR 261C, there's definitely something wrong elsewhere.