FJ60 2F stumbles, high idle, rough and dies @ low rpm (1 Viewer)

[Briarwood]

This morning my '84 FJ60 (2F) started the same problem it had last year. It has been running really great up till today. I stopped at Home Depot on the way to work. When I went back out it was hard to start, - like it had no gas. When it finally started, it cuts off at idle unless you have the choke out. With the choke out it races at 2500+ rpm. You can put the choke back in once you start driving, but if you slow down for a turn or stop it will stumble and cut off. Runs really rough and weak in 1000-2000 range.

(The only thing different first thing this morning was that it idled with the choke out for perhaps an extra minute when I first started it up while I had to run back in the house for something, - but it rode fine on the way to Home Depot. I think last year when this same problem started the same thing had happened in the morning)

I seems like a valve or switch is getting stuck. I messed with the EGR valve and can hear it clicking when I put suction on on it. Last time this happened I replaced vacuum lines and PCV valve but that didn't really help, - it acutally sort-of fixed itself after a 3 or 4 weeks of acting like this and mostly sitting in the driveway. My best guess was it was bad fuel then. This time it has been running fine since my last fill-up and I still have 1/2 tank.

Last year I put a re-built carb from cruiserparts.net on it. Also replaced cracked intake/exhaust manifold. New fuel pump / filter / vacuum hoses too.

Any ideas what to look at or try? Thanks !

 

[rusty_tlc]

I'd start with simple stuff like looking for disconnected vacuum & electrical lines, and checking the bolts that hold the car to the manifold.

 

[2mbb]

do a search for idle cut solenoid or "ics". you should test it by applying 12V to it to see if the solenoid is opening ("clicking"). The you can do the "green wire mod", ie. attach the negative wire directly to ground to see if the probem goes away. If so you have a bad wire or a bad emissions computer.

 

[Briarwood]

Thanks. There's only one set of wires I can find connected to the carb. When I connect / disconnect them I do hear a click, click, click. Is that the ICS? For some reason I thought the only the FE model had an ICS?

 

[Briarwood]

Thanks. Haven't found anything out of order yet, but still looking.

 

[Michael Hanson]

Try 2 cans of carb cleaner into the carb. with someone holding down on the gas. MIke

 

[Briarwood]

Just spray it into the air intake?

Try 2 cans of carb cleaner into the carb. with someone holding down on the gas. MIke

 

[Michael Hanson]

Yes pop off the top and spray down both barrels with some one keeping it running. MIke

 

[csd4682]

I am in the process of geting my cruiser running, and had all of the same symtoms as yours when I did have it running briefly. It ended up being cloged jets. One other thing I found that I have not seen anyone on here mention before, is that the secondary slow jets had hairline cracks all the way down them. I think whats happens is they get pluged and the fuel pressure cracks them.

 

[Briarwood]

Thanks. I lined up a real mechanic to look at it start of next week, and I'll pass all these notes along to him. Hopefully I'll post back with updates soon.

 

[dannymontani]

An old fella mechanic down the road, who has a cool shop, and used to race all around the country told me something of an old mechanics method of removing all that good carbon on those valves. This a month ago last winter... here. Now, it's probably true, but he is and has been way into the 'fumes', and he's one smart 'coot. (Love'em) He has told me that they used to and still do poor a cup of water into that thar carb, while she's running nice and hot and racing the engine. Man oh man.... he says... laughing. Gotta love it... dunno why I've never heard of it. "Curious and inquiring minds want to know"

Ok fer some input here......

 

[tucson_sailors]

Water injecting a carb?

An old fella mechanic down the road, who has a cool shop, and used to race all around the country told me something of an old mechanics method of removing all that good carbon on those valves. This a month ago last winter... here. Now, it's probably true, but he is and has been way into the 'fumes', and he's one smart 'coot. (Love'em) He has told me that they used to and still do poor a cup of water into that thar carb, while she's running nice and hot and racing the engine. Man oh man.... he says... laughing. Gotta love it... dunno why I've never heard of it. "Curious and inquiring minds want to know"

Ok fer some input here......

Hmm, every time I hear of someone in MUD doing something similar it involves a river, and water flowing over the hood. Generally not a happy thing.

I would suggest carb cleaner, or seafoam in the gas to see if it will clear any varnish deposits. Also check for a clogged fuel filter, or a failing fuel pump. If you want to decoke the top end of the engine, people have been known to use the big vacuum line (brake booster) to suck seafoam directly into the top of the intake manifold down into the cylinders. Will put out white nasty smoke like no tomorrow, but that won't really clean anything out of the carb, if the carb is the issue. But it looks really cool, and is a helluva lot easier than pulling the head.

Glenn in Tucson

 

[trucruiser]

Thanks. I lined up a real mechanic to look at it start of next week, and I'll pass all these notes along to him. Hopefully I'll post back with updates soon.

Mine is doing this exact thing, Cant wait to hear the fix

 

[MSK79]

Any news on this issue?

 

[rckhound]

Did you check for any leaks around your intake. My truck was doing something similar and it ended up being a leak at my intake manifold. Check for bolt tightness around your exhaust and intake manifolds. Since you replaced that last year maybe something came loose if they were never re-torqued down.

 

[dannymontani]

Hi guys, been on the road alot to a little town 130 miles from here. Done the trip back and forth now three times with at least 150lbs of camping gear, a canoe (53lbs) and many tools to at least 250lbs or around there....and wife....smidge at 120. Thats pounds not age! haha Since my desmog is about 100 percent from what I can tell......the carbon deposits that have been in the old girl are more likely that not, on the side of the road somewhere. Big pass both ways. The decarbonize that I mentioned above number 11, seems to have really helped, but the hard driving is also absolute necessity I believe. FEELS like it drives differently. Smoother, not as rough, but not quite perfect. I'd rebuilt the dissy, not recurved as I'd like to....just wish somebody would share the 'Big Secret' as I am at the limit of my advance for here in the Montana mountains. I am at 4500 feet so kept the HAC and two VCV valves. I am now running on almost zero idle mix screw and getting a rich burn. I am ALSO getting 17MPG through the mountains going through at least 5500ft. I have made up new very illustrative drawings of what I've got going on with the desmog as well as descriptive photos. I may also have one of the HAC valve vacuum lines mixed up and nothing running to either the CB (choke breaker) nor the other pot the CK (choke opener) I hope to have this all drawn up in Adobe Illustrator from my hand drawings over other posts on the FAQ's pages as soon as possible. Any input to what is above would be great. AS well as I hope this helps. Hey, drive the sh*t out of it to decarbonize. Best, D

 

[83FJ604ME]

Wow, I'm glad I'm not the only one experiencing this. I will try some of your suggestions, but if anyone has any more I would be glad to hear them.

 

[Briarwood]

follow-up

Mechanic says problem is that the idle control solenoid (or maybe he said fuel cut solenoid) is opsning when it should be closed, and closing when it should be open. Said wires to unit look like they mis-routed and fried on manifold. He's been looking for a new wiring harness but no luck finding one so far.

I'm going to research more about the ICS (or maybe FCS) and try to learn what I can. Also read somewhere that the solder joints where these wires hook into the Emissions Control "Computer" can crack.

I still believe it is an electrical problem of some type, because it goes from good to bad in a moments notice. Problem is it is staying "bad" now all the time.

Any info on wiring harness for '84 FJ60 is more than welcome. THanks.

 

[Briarwood]

Update so far...

Seems that "bucking and surging" was fixed by re-wiring the Fuel Cut Solenoid switch in the carb. The old wiring was fried. However, still can't trace idle problem (engine won't run under 1500 rpm). Low steady vac reading off manifold (8 or 9 inches) Carefully replaced all hoses, - found two suspect but no improvements. Pull carb and looked for cracks in manifold - looked okay. Not brave enough yet to pull manifold off. Re-assembled everything (proud of that fact) and isolated brake booster for manifold, - still no improvment in idle or vacuum level.

Going to start plugging off lines and try to bypass EGR assembly to see if anything gives. Will also triple check routing of all vac lines.

Wish I had taken a vacuum reading when it used to run well. Wonder if problem is with engine/valves instead of a leak somewhere...

 

[Briarwood]

Hooray! It's working !

I'm too happy and proud to feel stupid...

I've learned how to replace all vaccum lines (even the "hidden 4" on the backside). I can pull a carbuertor off, check the manifold, and put it all back together, - including all the throttle linkages. I can test vacuum switches and trace wiring.

Turns out the problem was due in part to a bad wire to the Fuel Cut Solenoid. It would connect sometimes (like when the car was at the mechanic), then not at other times (like when it was back home), - probably causing the bucking and surging. The wire finally broke at the connector, and that's when I could see it had been like that for a while.

Fixing the wire fixed the bucking and surging, but she still wouldn't idle. That's when I started the wild goose vacuum leak chase (but did find 2 suspect hoses).

Finally tried "hard-wiring" the fuel cut solenoid to the battery, - and she worked! Why did the FCS not work if the vacuum switch that controlled it working? Was it the ECC? Well... traced it back and found a blown fuse (the 10A engine fuse) that probably happened sometime after the bad FCS wiring broke apart. Replaced fuse and all is well : )

Next steps I'll learn how to fine tune the idle, then sneak down to the emissions test station and try to get my tags renewed.

Thanks for all the help and advice everyone posted!