Suddenly won't idle - now won't start

[gcrump01]

1980 FJ40 - Trollhole carb - everything running fine for the last few weeks, now it suddenly won't idle. I verified power to the idle solenoid & I can hear it clicking when switch is turned on.

Ugh, beautiful day in GA - I should be driving around. Where to do I start?

 

[Pin_Head]

Check for large manifold vacuum leaks, like the brake booster hose and anything else that connects to the manifold like the EGR. EGRs sticking open are a known problem with idling on 79 and up 2Fs. Try whacking the EGR with the handle of a screwdriver.

 

[gcrump01]

Desmogged - EGR is gone, holes in manifold plugged w JimC's EGR blockoff plate.

Brake booster connections are snug.

 

[Pin_Head]

I guess it must run fine then. Everything that can cause it checks out fine. Carry on.



It is either lack of idle fuel or lack of manifold vacuum. Chinese carbs hve been known to have machining chips in them that can clog fuel passages.

 

[tls3601]

It could be your fuel pump is going and debbris from the rubber diaphragm are sloughing off leading to plugging of your idle circuit-ask me how I know! Crank it over with fuel line disconnected and let it pump into a cup and see what is in the gas. Of course disconnect coil wire so she wont start

 

[honk]

It's good that your idle solenoid clicks when appropriate but that doesn't tell anything about the fuel passageway(s) behind it.

A good thing to try would be to remove that solenoid and spray some carb cleaner into the resulting hole; another might be to search out "Okie Tuneup" (or any of the variations) and do that; and one even simpler could be to bop on the corner of your float bowl to free the possibly stuck float..

With carbs a little spec will do you......in.

 

[gcrump01]

It's good that your idle solenoid clicks when appropriate but that doesn't tell anything about the fuel passageway(s) behind it.

A good thing to try would be to remove that solenoid and spray some carb cleaner into the resulting hole; another might be to search out "Okie Tuneup" (or any of the variations) and do that; and one even simpler could be to bop on the corner of your float bowl to free the possibly stuck float..

With carbs a little spec will do you......in.

Sprayed carb cleaner in the idle solenoid hole - no change in the idle problem. I'll keep going..

Marshall - any thoughts? @Trollhole

 

[Pin_Head]

Try spraying carb cleaner in the solenoid hole while it is running to see if it idles better. Try adjusting the idle mix screw. That way you can verify whether the passage downstream is clear or if it is clogged.

 

[edwjmcgrath]

Will it not 'idle' or not run? If you crank down on the idle speed screw (which opens the throttle), you should be able to get it to idle even if you have a significant problem. Then you can check the vacuum at idle and spray around to look for vacuum leaks.

 

[gcrump01]

It runs fine with choke pulled out slightly. Choke wasn't even hooked up until today & it idled great all week. Seems like debris since it was such a sudden change.

 

[edwjmcgrath]

When you pull the choke closed and start it up, is the choke plate completely closed? The choke breaker should open the choke a bit to allow enough air for the engine to run. If it is disconnected or removed, that would cause it to not run unless the choke was pulled out slightly.

 

[sadam_husain]

if you've done all the obvious and basic things the next step is to pull it apart and blow all the galleries out with compressed air the idle circuit has the smallest metering and is the first passage to get blocked by any debris that has managed to get past the filter(s)

 

[sggoat]

1980 FJ40 - Trollhole carb - everything running fine for the last few weeks, now it suddenly won't idle. I verified power to the idle solenoid & I can hear it clicking when switch is turned on.

Ugh, beautiful day in GA - I should be driving around. Where to do I start?

When it "suddenly stopped idling" was it at a stop light(running) or did it work fine when you parked it at home, then the next day it wouldn't idle? Did it gradually get worst over a week or so? Did you notice any symptoms before the idle problem showed up?(like lowered vacuum(if you have a vac gauge)), did the engine slowly begin to drop idle RPM, or did it do it all of a sudden?--How about power? does the engine accelerate like it used to when you poke the throttle?
What is your ignition setup? points, or electronic? If it is points, go take a look at the phenolic rub bar on the points arm-almost sounds like the points are not even opening--symptoms are loss of vac(~2" at idle), low idle rpm(resulting in low oil pressure)---{retarded timing}

 

[gcrump01]

When it "suddenly stopped idling" was it at a stop light(running) or did it work fine when you parked it at home, then the next day it wouldn't idle? Did it gradually get worst over a week or so? Did you notice any symptoms before the idle problem showed up?(like lowered vacuum(if you have a vac gauge)), did the engine slowly begin to drop idle RPM, or did it do it all of a sudden?--How about power? does the engine accelerate like it used to when you poke the throttle?
What is your ignition setup? points, or electronic? If it is points, go take a look at the phenolic rub bar on the points arm-almost sounds like the points are not even opening--symptoms are loss of vac(~2" at idle), low idle rpm(resulting in low oil pressure)---{retarded timing}

Worked fine when I parked it one day, no indication. Next day I started it and it wouldn't idle.

 

[gcrump01]

Idles fine now - all of a sudden. I drove it a round a little with the choke pulled slightly to keep it running. When I got home, pushed the choke in & it idled fine. That was last night. Today, started it and it idled fine - then driving at about 40 mph, 4th gear, it started skipping and gasping for fuel. Sounds to me like debris as it appears to be moving around. I think I need to pull the carb & clean it - blow out all the passages with compressed air, as suggested earlier.

 

[edwjmcgrath]

Just a guess but I'm going to say you'll find metal shavings in there.

 

[MOTOV8R]

My 79 does this. There is some loose wire at my fuse box. Sometimes it just stops idling. If I reach down and push on the fuses it will start idling. I have troubleshot it a little but have not figured out the exact cause yet.

 

[gcrump01]

Really having no luck at all today. Cleaned out the carb, blew compressed air through it, etc. I did find some small metal looking shavings.
Anyway, put it back on, drove it about 4 miles and everything ran great, idled good at stops without any choke. Got home cut it off just to open the hood & make sure there were no leaks. Now it won't start!!

 

[emac]

do you have fuel in the float site glass? Are you getting fuel? Clean fuel filter? I was just recently have a similar issue. I think my main issue was a loose connection on the idle solenoid plug.

 

[gcrump01]

I'll check the site glass to be sure tomorrow - really frustrated with this & pretty much done with it for today. I did crawl under & the fuel filter looks clear.

About ready to try another carb.