Can't drive 55.......well sort of.

[woodybeone]

This just started on my '89.
When I am driving at highway speeds (55)I have no more top end. Floor it and it just maintains and sometimes looses ground.
When I floor it from a standing start it will hold first gear and the engine starts pinging until I leave off a little and then it shifts into second then third. When in third it
will downshift but again will hold second gear not gaining much speed until I lift a little then it will shift into third.
When in reverse trying to back up a steep hill it seems like it has no power and stops moving. Shift into 4wd and low range then it makes it.
Rig has 130K but the tranny seems to shift OK under light throttle.
Engine is running fine, just tuned.

Anybody have any ideas ?

[joe]

If as you say it's just been tuned my first guess is a plugged catalitic converter. When was the last time it was changed?

[andy d]

who tuned it and what did they do? possibly a huge vacuum leak. what does tranny fluid look like? how did it run before it was tuned?

[ August 10, 2002, 08:23 PM: Message edited by: andy d ]

[woodybeone]

Never changed the cat. Engine revs/ races good when in park or neutral. Thought a bad cat would first cause low speed problems.

[Damage, Inc.]

Yeah...my first thought is the cat...

[woodybeone]

I tuned it about 6 months ago. Ran fine until recently.

[porchpiggy]

Had a similar experience with an old dodge truck, clogged cat.

[Bombadier]

My '83 Olds 98 did that too, but it turned out to be a MASSIVE vacuum leak.....that crappy mill had more rubber vaccuum hose than engine.....but yeah, a clogged converter will do the same thing, just not as badly as my Olds did.....

[gsmikie]

dont forget fuel filter

[Crazy_Jeepman]

Re-check timming ;)

[woodybeone]

Well I sprayed some carb cleaner around and there is a leak on both sides of the carb at the base. Snugged the bolts and it's still there. I'm going to replace the gasket and check the spacer for cracks.

[derf]

Originally posted by woodybeone:
Well I sprayed some carb cleaner around and there is a leak on both sides of the carb at the base. Snugged the bolts and it's still there. I'm going to replace the gasket and check the spacer for cracks.If you've had any overheating problems like me, it could be a warped intake manifold. I have similar symptoms in mine.

[Don S]

Originally posted by woodybeone

Well I sprayed some carb cleaner around and there is a leak on both sides of the carb at the base. Snugged the bolts and it's still there. I'm going to replace the gasket and check the spacer for cracks.woodybeone...
Carburetor throttle-shafts when worn can cause idling problems with vacuum leaks but shouldn't effect higher RPM... CUL.. ;) ..ds..

[woodybeone]

Funny you mention that derf. I blew the water pump on the interstate at night coming back from Carlisle and the temp was up there pretty high by the time I saw the steam and looked at the guage. However it was acting up a little on the way down and back priorto the water pump incident.
I'm going to get a new gasket and spacer and start there.

[86Wagoneer]

I had the same EXACT problem in my 86 Wagoneer, it wouldn't go over 45 without some distance to get me there. I changed the air filter, pcv valve and attached 2 vacuum hoses and it picks up speed easily now. Only problem is my tachometer reads about 5000 rpms, and then I have to let off the gas in order for it to shift. It won't shift on its own. Once I reach 55mph, it will NOT shift again, no matter what I try.

I have a red vacuum hose just dangling by the tranny and a green and yellow vacuum hose wrapped around my brake lines. I have no idea where these go, maybe someone could give me some hints?

The guy who rebuilt the motor, I am sure did all this!!!!!!!!

[infincool]

unless you KNOW your fuel filter is good CHANGE IT! I went through this last week. Same issue and I had recently ( 6 mos) changed fuel filter (s) ( I run an inline before the pump too) and that resolved the issue. The filter looked clean enough til I removed it and looked at it more carefully. Another possibility and I've mentioned it before but for those who missed it, ther is a solenoid ( bowl vent solenoid ) that opens when the key is off to let the carb bowl vent into the Charcoal canister. The valve stuck open causing the carb to suck charcoal from the canister into the bowl and clog the jets intermittently of course. Took me FOREVER to chase it down. I changed everything I could think of ignition module, TFI upgrade , fuel filter, sending unit filter, added inline filter, fuel pump, new carb. I finally got so mad I decided to rip apart my new carb and sure enough the bowl was half full of charcoal bits. I can't be the only one this ever happened to so if all else fails look into it. PS I could still hear the solenoid opening and closing when I turned the key but it wasn't closing all the way.