should i swap engines or fix this one?

[swynx]

My 1994 b4000 has like 260k original miles. No leaks, doesn't smoke, never gets above half on the temp guage. Replaced plugs with some platinum Plugs, changed oil. New rear main. Sea foamed gas and oil, Haven't done a complete tune up as I've been moving. Ran better after sea foam.

It idles fine and runs fine till about 3k rpms. after that it's basicly bogging down feels like I'm towing something. After 4k it almost always spudders. If I keep it in the power band between 2-3k it has power.

Driven lots of 4.0s with 3.73 gears and they were all way quicker. Drove this truck 6 months ago and it was way quicker. all the way from 1-5k and 0-65, this thing doesn't even put me in my seat.

I have a 4.0 with 80k on it I can get for 100$ but I wanna save this one if it'll be easier than swapping. I'm almost thinking I need new coil and wires plus fuel filter might do it?

Opinions? The truck has no top end. In fact I doubt it would pull 33s with 3.73 on flat ground outside of second, check the cat tomorrow.

 

[fyre82]

Give it good going through for a complete tune, including checking base timing.
Definitely change the filters and run OEM recommended ignition parts.
But it does have 260k, could be just getting tired. Anything mechanical that you do to an aging engine can have repercussions elsewhere, i.e. a head job on an aging engine can cause blow by in worn rings.

Swapping out can be a weekend job and for $100 it's a good option.
However, the old adage says; "If it works, don't fix it."

Another option might be to pick up the $100 engine, put it on a stand and go through the gaskets that commonly leak, valve covers, pan. Clean it up and make it pretty for when the original gives it up. Then don't swap it until you are ready.

But if you want a race car, why have a truck?

 

[swynx]

I was going to give it a complete tune up, compression test, test fuel. Change ignition components. I think it may just be getting old and tired. Possibly low compression. The other engine comes with a4ld and another t case ( electric) I just gotta pick it up.
Hopefully this weekend I'll get some answers on this engine.

Not that I want a race car, just want it to run efficiently as I bought it for a trail rig.

 

[RonD]

My '94 4.0l just turned 300k, finally changed the factory spark plug wires, ran much better
Original everything else, coil, injectors, pump, FPR, I have changed the fuel filter, water pump and heat core, compression average 170psi

Heater core on these is the water pump by-pass, no heat control valve, so core always has coolant flowing thru it, if core gets partially blocked temp will randomly spike, odd problem to diagnose, so just a heads up.
Core is cheap, under $30, and 4 screws to swap it out, 20min job.

I would save the other 4.0l, and see what compression is on the B4000

 

[snake]

Comp test and check the cats for clogging.

 

[hank857]

I have a 94 and it has over 300K 0n it and had never had any major work until last summer and it turns out that is still didn't need it! I thought I had a blown head gasket so pulled the heads to R&R the gaskets (thats all). Anyhow still had leak and it turned out to be the water pump manifold where it enters the block. Anyhow I replaced ALL ignition components as they were OEM except for plug wires trying to find a miss. I did all the tests, took it to a local garage and they confirmed my findings for compression, timing etc. Ended up R&Rg the injectors! Had one or 2 that were partially clogged. They had been removed and taken to an injector shop for cleaning check out at about 150K. Anyhow got the water jacket fixed and had them R&R the timing chain and gear. These things if taken care of seem to last and last. I would suspect you could have a fuel flow problem (dirty filters, weak pump) that cant keep up with demand. I just R&Rd the fuel pump and fuel filler hose on mine again all had been OEM. I would recommend you check fuel rail pressures and look in that direction. 6 injectors the fuel pump, fuel hose ran me around $500 with my labor. The fuel pump really fairly easy if you pull the bed, same with hose. Injectors require a little more effort but not much. Wish I was closer as I would buy the engine for $100 just to have as the one poster indicated above.

 

[GentleRF]

I was going to give it a complete tune up, compression test, test fuel. Change ignition components. I think it may just be getting old and tired. Possibly low compression. The other engine comes with a4ld and another t case ( electric) I just gotta pick it up.
Hopefully this weekend I'll get some answers on this engine.

Too bad you and I live so far apart and I'm on a fixed income or else I would do some help out with the wrenching and maybe buy the A4ld and t-case.

Rick in East Bremerton, WA

 

[jhammel85]

I'd check compression 1st and go from there. If those numbers are good then keep it going!

 

[swynx]

I don't want to replace the engine of I can help it. After thinking about it I think it's fuel flow. It doesn't act as if it's not sparking but more so that it's starving for fuel at high rpm. Ralph said to come pickup the engine/tranny/t-case whenever, after I move I'll set it on a stand give it a tune up, new gaskets, maybe some small performance stuff. Make sure it's clean. If I get this engine figured out, I'll let you guys know why was wrong.