Ignition Coil Question (1 Viewer)

[ace7141]

I need your help! I am a illiterate when it comes to electrical diagnosis. I am learning.. slowly. Can anyone confirm this is the correct resistance? FSM says .5 - .7 I want to make sure I am using my multimeter correctly.

My truck has been stalling, bucking, and dying after about 15 - 20 minutes of driving. I just replaced the fuel pump with OEM. Replaced all fuel filters and fuel lines in the engine bay (did not touch fuel lines under truck running to tank). I am trying to track down the source of the stalling and bucking. Some reading led me to believe it could be the coil or igniter.

Any guidance is appreciated! Thanks everyone!

 

[Gretsch]

I can't help on the electrical diag. But whats the fuel level in the carb site glass when it dies? Should be right in the middle of the glass. Have you made sure you are getting adequate fuel up to the carb?

Seems I have been offering this solution up a lot past few days for various threads, but have you checked your carb ICS? Check that it works properly? Fairly common for the ground for the ICS to go bad allowing it to close cutting off fuel to the carb. You can check by plugging and unplugging it with the engine off and the key to the on position. Should hear an audible click when plugging it in. When this happened to me the truck would buck violently at highway speeds, like hitting a wall at 60MPh repeatedly. Would die after coming to a stop. Is it intermittent? Will giving it gas allow it to not die at idle? Assuming you are still talking about the '84 FJ60 in your sig line. Can see additional info in this thread:

1984 FJ60 Engine Sputtering, Bucking - FIXED!!!

Hello all. Recently picked up my first LandCruiser FJ60. 1984. Great condition overall. I am about 4 days into this so totally new to these vehicles. PO had the carb rebuilt to chase an engine idle problem. Seemed to fix the issue for awhile but during trip home with it on the highway, the...

forum.ih8mud.com

I fixed it by reflowing the solder joints at the emissions computer. Never did it again after that. You can bypass the ground wire by grounding directly to the carb as a test to see if your issues go away. In the thread above. I don't know if this is your issue or not but you might consider at least verifying the operation of the ICS as its really quick and easy to do. GL.

HTH

 

[ace7141]

Robert, thanks for your reply!

I have a Weber 38/38 on my truck, so I do not have a sight glass. My reading suggests there is not an ICS on my carburetor. Can you confirm this is just on the stock aisin carbs? I was going to replace the accelerator pump diaphragm on my carb just in case it could be the issue.

When I give the truck gas, it will die. It seemed to idle, albeit rough, but any input from gas peddle kills the truck. Today I cannot get the truck to even crank up and idle. Don’t want to smoke my starter, so I gave it a rest and hit up the forum.

I do not have an operating carb cooling fan, but my understanding was this only operates at shutdown to keep gas from boiling in carb.

 

[Gretsch]

OK yeah sorry.....I assumed stock Aisin carb. So you can disregard my previous post. I don't know anything about the weber carbs.....other than they don't seemed to ever work reliably on a 2F....which again I am assuming you have here. I would guess you have no ICS so anything I posted thus far is unfortunately useless to you.

That is my understanding as well on the carb cooling fan. I think it was more of a work around from Toyota. I guess it could be still relevant with the Weber, but I am not sure. Hopefully someone with Weber carb experience will chime in here. Sorry for the bother on this one.

 

[klinetime574]

The Weber does not have an ICS. Easy things to check on your Weber: make sure the choke isn’t stuck closed, and check your fuel filter to make sure it looks normal.

Also, I ran a fuel pressure regulator with my Weber. I seem to remember their manuals say 3.5psi MAX pressure. I never took a reading for what the stock fuel pump puts out, but I ran it just to be safe. My Weber ran great. Ditched it to get AC idle up functional, and it’s just more “correct.”

 

[ace7141]

Klinetimes74, thanks for your reply!

The choke is not stuck. I have an electric choke, instead of manual. Live in Mississippi, and I am not even sure the choke has ever been needed. The flappers move and snap shut with good tension, but not tightly or stuck.

I have put a good 5K miles on the truck with the Weber (I bought truck and Weber was already on it) and it has worked great thus far. This issue of bucking and stalling just started out of nowhere one afternoon drive.

I have checked the small filter at front of carb to see if fuel delivery was being restricted, but it was clean. I have new fuel filter before the fuel pump, and after the fuel pump, before the carb.

I was thinking it may be the coil or igniter since fuel delivery didn't seem to be an issue. But I am still not sure.

 

[OSS]

Coils are cheap so might as well replace it if it's old . Most igniter malfunction symptoms are engine runs fine then conks out- nothing. Can't restart, no spark, then sometimes when it cools down it starts working again and engine runs fine- until it conks out unexpectedly again.

Bucking is almost always a lack of fuel supply. As the throttle plate opens, if there's a blockage in a jet or fuel supply is insufficient, the engine immediately runs too lean cuz throttle plate is opening but not enough gas is getting sucked in.
Bucking is almost always a carb problem

 

[ace7141]

OSS, thank you!

My current game plan is remove carb and clean it, inspect jets for blockage. I have an accelerator pump diaphragm assembly I am going to replace, as some of my reading on Weber carbs suggests that it can cause these issues if failing.

I agree, probably just go ahead and get coil.

I am going to give the igniter a good once over, clean it up and check connections. The first time my truck did this, it was bucking and stalling, then died. The second time my truck did this, it sputtered, backfired, and died - then just would not crank. I coasted into a gas station parking lot. I let it sit until morning, and tried to crank it (my assumption was it was temperature related) but even with a cold engine, it still would not crank. I poured a cup of gas directly into carb, and was able to get it to idle, roughly. When I pressed the gas, it would die.

I don't seem to have any pressure when removing gas cap, so I was going to rule out the Charcoal canister contributing to this issue.