Loss of engine power and shuddering - HELP

[anton]

Before I left Chicago on Dec. 13th I restored the exhaust system from the manifold to the tailpipe on my 84 FJ60, had it tuned up and passed emission test with one problem - I had to replace my gas cap as the current one was deformed when I drove over it. Then I made it to Sacramento in 3 days without any problems in cold weather. So I figured I will treat my old Bessie to an oil change at Jiffy lube where they also checked and topped the oil in the tranny, transfer case and both differentials.

But from there everything seems to be going down the hill. When I got to Sonora I noticed that the new oil plug Jiffy Lube replaced for me is dripping oil. I had to tighten it almost a full turn and then some a few times afterwards. In Arizona the alternator belt broke, so I replaced it and the PS one (I have no AC) at the same time. While looking inside the engine compartment after replacing the v-belts off the I-10 shoulder I noticed that the fuel pump squirts gas from what I later learned was a vent hole. Nonetheless I have plugged the hole with a piece of rubber electrical tape made into a small cork and continued driving to Las Cruces where I got a new pump at a local Napa store and replaced it and fuel lines in engine compartment at their parking lot. I also had some small coolant leak at the heater valve on the firewall which I took care of at the roadside. Another problem was a corroded fuel pickup/return pipes on top of the tank which started leaking and I had them fixed at Van Horn where I finally gave in and went to the shop where they dropped the tank and replaced it after lots of swearing and grunting noises trying to unfasten rusted bolts holding tank straps. I also replaced all the rubber fuel hoses at this point. I thought my troubles where over as I figured that that will take care of the main issue which has been hounding me for almost a week now. But to no avail.

The main problem I'm having now is that since the original pump went bad, ole Bessie, after running for about 2 hours from the cold start in the morning would just lose power at my cruising highway speed (55-65) and then I'd have to let her rest for half and hour and she would run for about 10-20 miles with no problem and the whole thing would start again. Basically it feels like the engine is stopping pulling the truck and if I keep it in gear it stats shuddering back and forth until I put it in neutral and cruise for about 30 seconds. Then I'm able to put it in gear and press the gas pedal and unclutch it again as soon as I feel it losing power again, till I find a good spot to park off the shoulder and let her cool down for a while.

I'm saying "cool down" but I don't mean by it that the engine is overheating - at least not according to the gauge whose needle stays pretty much in the bottom half of it. I check oil and coolant levels religiously and I don't seem to be loosing oil - I did put 2 quarts in since oil change in Sacramento but I guess by the size of the slick in the parking lot of Miner's Inn in Sonora, that way over a quart must have dripped out through the leaking drain plug there.

So all that time I though that the problem with losing power was due to the leaks in the fuel lines and carburetor sucking air (I really have NO IDEA - )

Could someone pleas help me with advice? I'm in the middle of Texas and totally run out of ideas. Is ole Bessie very sick? Is it something I could fix myself?

Happy New Year's everyone -- from Ozone, TX

 

[soggy60]

When you say "shudder" , do ya mean bucking as though the engine in almost "off then on, then off, then on"./

If so, it's fuel problems....with all the stuff ya had done, did ya replace fuelk fileter ?
Also, try running driving with filler cap off. Tank should not go to vacuum, but if charcoal canister is plugged and filler cap doesn't vent correctly, your fuel pump won't suck against a vacuum....

Pete

 

[anton]

When you say "shudder" , do ya mean bucking as though the engine in almost "off then on, then off, then on"./

Yes, just like that. She if I keep the gas pedal pressed it does that.

If so, it's fuel problems....with all the stuff ya had done, did ya replace fuelk fileter ?
Also, try running driving with filler cap off. Tank should not go to vacuum, but if charcoal canister is plugged and filler cap doesn't vent correctly, your fuel pump won't suck against a vacuum....

Pete

I replaced the filter 3,000 miles ago when I did tune-up, along with spark plugs, dist cap, and rotor.

What bugs me though is why i was able to get to California from Illinois, pushing it really hard throught the Rockies and Sierra Navada without any snag. Was it because it was so cold all along the I-80? I really am pissed now that the FSMs for F2 and emission system didn't arrive before I had to go. I read a lot of posts here and would really like to go over all the vacuum lines to make sure everything is connected correctly.

 

[swagdan]

I'd replace the fuel filter again. You say you put a new fuel filter in 3k miles ago....then replaced tank and hoses etc? My guess is that deposits and other crap have been knocked loose and your newish fuel filter did it's job and trapped them.

I had the exact same symptoms on the way down to Moms place over the holidays. I replaced the fuel filter on the side of the highway and no problems since. It's an inexpensive first step on your way to eliminating other possibilities.

Yes, just like that. She if I keep the gas pedal pressed it does that.



I replaced the filter 3,000 miles ago when I did tune-up, along with spark plugs, dist cap, and rotor.

What bugs me though is why i was able to get to California from Illinois, pushing it really hard throught the Rockies and Sierra Navada without any snag. Was it because it was so cold all along the I-80? I really am pissed now that the FSMs for F2 and emission system didn't arrive before I had to go. I read a lot of posts here and would really like to go over all the vacuum lines to make sure everything is connected correctly.

 

[chitown40]

Did you replace the exhaust manifold itself? It sounds like a clogged exhaust to me. If you re-used the original manifold, my bet is the heat riser is stuck closed. Symptoms would include loss of high-end power. Or maybe a clogged cat?

 

[JBBenson]

I had I think a related problem. While sitting at the curb for two days, the gas in my tank rose up the filler tube and spilled down the side of the car. I used a bulb syringe and sucked out all the gas until it fell below the metal flap.

After starting and running the engine for about 3 minutes to check it, I opened the filler cap again and there was a sucking sound that pulled all of the gas (yes it had filled up again) back down the tube. Car stunk of gas for about a day, now its all good, having reached some sort of equilibrium.

Let me say at this point that the car does bot have a OEM cap, so any one way venting issues are maybe the problem. The cap has a "closed" position that is a little wobbly, letting some air in as needed. I had not fully closed it at the last gas stop, thus screwing up the balance in the system.

I think.

Don't know if that is the case with your car, but just shows that any mods have unanticipated effects. Change one thing, change everything.

Sorry for rambling.

 

[anton]

Thank you all for the feedback. I will definitely try replacing the fuel filter first thing Monday morning. I tried driving with the gas cap not screwed on tight and got the same symptoms as described while doing that.

As to the exhaust, I replaced the whole run, starting at exhaust manifold, the piece that connects to the cat, the cat itself, and the tailpipe piece with the muffler, as it all was botched by some muffler shop years ago by cutting off original flanges and welding some crap together.

 

[LandRaper]

I think you're on the right track with the fuel filter. I had the same problem two days ago when I was driving my newly inherited 1985 FJ60 back from GA to PA, and the fuel filter totally solved my worsening shuddering problem. The Cruiser hadn't been driven much for a few months, and I think my first new tank of gas cut a whole lot of gunk loose.

 

[anton]

I think you're on the right track with the fuel filter. I had the same problem two days ago when I was driving my newly inherited 1985 FJ60 back from GA to PA, and the fuel filter totally solved my worsening shuddering problem. The Cruiser hadn't been driven much for a few months, and I think my first new tank of gas cut a whole lot of gunk loose.

Yup, this seem to have been the case. I got a new gas filter at Ozona, TX Napa and drove 200 miles to San Antonio without any problems.

Thanks again to all of you.