FJ60 Bucking under throttle and stalling (1 Viewer)

[dhuffste]

Today my 60 started to stutter, and buck while under throttle, and then stalled out a few times when shifting between gears, and then decided it didn't want to make it up a hill and died on me. I managed to get it started back up, it would start and idle just fine while limping it up a hill and stalling over and over. I put in 4LO going up the hill and that helped a bit, but it still stalled out once and continued stuttering. Once I got to the top of the hill I fired it back up and it didn't do it again until later that day, when coming home in second gear it started to buck and stutter coming up the hill to my house (seems to be mostly happening under load, Highway acceleration, up hills) It feels like it may be a fueling issue based on how it was behaving, but I'm not entirely sure. I know its not the fuel pump (99% sure) since I replaced that a month ago and the old pump was definitely faulty.

The other day I also had a coolant hose explode and spray hot coolant all over the engine bay, but got that fixed up. Not sure if this could have anything to do with the current issue, but I'm mentioning it just in case.

I looked at the glass fuel filter and that seems pretty clear, so I'm under the impression its not a fuel line blockage.

Anybody have any ideas on where I should start or had a problem like this?

Thanks

 

[cruisermatt]

just because you replaced the fuel pump doesn't mean it's still good. was it a OEM pump? You said the sight glass is clear, is there fuel in it??

Other then that I would check all your main power connections for resistance. Main engine ground being corroded can do things like this

 

[OSS]

The primary jet in the carburetor float bowl is situated at the back of the bowl. A fuel jet is simply an orrifice that the fuel gets sucked into. When the cruiser is driving up a hill, the carburetor is tilted back so that the jets are at the low end of the angled bowl. If there's a piece of crud drifting around inside the float bowl, it can lodge against the jet when the carb is tilted back (when angled up a hill) and partially block the flow of fuel going through the jet. The problem can be intermittent.

If a jet gets a blockage, even a little one, there's not enough fuel getting sucked into the engine and the engine will buck and hesitate when trying to drive up a hill... or stall due to fuel starvation when the gas pedal is depressed.
Idling will be fine though because the idle fuel circuit doesn't feed through the primary jet.

I've experienced this problem first hand - and the culprit was an almost insignificant little piece of crud drifting around inside the bowl. Once I got rid of it, engine ran normally again. I have no idea how it got in there.

While your problem may not be the same, I sure as heck wouldn't rule it out as a possibility.

 

[Seth S]

Maybe you have a blockage in the carb which lead to a leaner mixture resulting in a hotter running engine and the demise of your already tired coolant hose. Now the carb problem has escalated to a bigger issue.

 

[cruisermatt]

If you’ve had the carb off at all recently make sure the mounting studs are tight

 

[g-man]

make sure your fuel cut solenoid is clicking. Typically when you have a bad contact...usually at the green plug on the carb, stalls, stutters....etc are normal.

 

[TRobKC]

I've been having this issue as well. My fuel pump is OEM, the carb was properly rebuilt and stock, fuel lines and fuel filter are replaced after the fuel filter. I sprayed some carb cleaner and light compressed air into the carb to try and clean it out and also backed out my idle mixture screw and cleaned it. I couldn't see any obstructions but you never know. I would say it's been better but still not solved. I also replaced my gas cap, and did the AC Delco charcoal canister just in case there was some kind of vacuum lock going on.

I can do a cold start and it will run for 15 minutes and then it will want to die fast on me if I don't really feather the gas. If I can keep it going for maybe 3 or 4 minutes it will go away. Then sometimes on a warm start it will try to die as well but I can feather it to keep it going. @dhuffste were you able to get your rig figured out? My next step is to test the solenoid valve (which was new with my rebuilt carb) and try some Sea Foam.

 

[Dodobo]

Had very similar symptoms and replaced OEM fuel pump with aftermarket and was mostly fixed for a while but still wasn't right. After months of chasing my tail I finally tried a new OEM fuel pump and problem was solved.

 

[OSS]

I've been having this issue as well

Just because a carburetor has been rebuilt in the past doesn’t mean that some crud later hasn’t gotten in to it

 

[pithicus]

Water in the fuel gives similar symptoms. Unreliable fuel pressure varying float level , or as OSS says, partial primary jet blockage.
Also double check the outlet and return line on the pump are on the correct hoses. The return line is at the top of the pump, the outlet is at the bottom.