hesitation / high idle

[hammer]

in recent weeks, my 84 fj-60 has had a increasing problem with hesitation . when i accelerate, i get a rough period where it almost feels like im slowing down, then it picks up. i have replaced all the vaccuum hoses, and checked anything else i can think off, but to no avail...
also, i have real problem with the idle. the truck will only run with the choke pulled all the way out, all the time. any attemp to push the choke it means an instant stall.. this has been a problem for years. since i will need to keep this car for the forseeable future, it has become a concern.
in the last year i have replace all the hoses, the manifold gasket, the distributer, and finally bought a whole new carb, but NOTHING fixed this problem.
i now turn to you guys here...any help will be much appreciated

 

[IDave]

I'd suggest you get a vacuum gauge and see what's up. I wouldn't be surprised if you have a leak somewhere.

 

[60wag]

Sounds like a vac leak to me too. Hunt around with a spray can of flammable carb cleaner. Check the manifold/head joint and the carb base. Just because the manifold gasket was replaced doesn't mean it can't be leaking. Carb base nuts may be loose. A vac gauge will help narrow the possible causes. Make sure the brake booster isn't leaking. Try capping off the EGR pipe going into the manifold. If nothing else points out a leak, remove the carb and inspect the intake manifold directly below the the carb for cracks.

 

[jwest]

As you're checking for the vacuum leaks, check the fuel cut solenoid.

 

[Otis]

I had a similar sounding problem with no idle on my '80 FJ40 and it was a bad ground to the fuel cut off solenoid. I spliced in a new ground and that solved the problem.

 

[65swb45]

Both good suggestions. Post back with the lowest rpm you can keep it running at, and what the vacuum guage shows at that point. You'll get more imput from the board when we have numbers to work with

 

[hammer]

i finally got the chance to use the vacuume gauge.
hooked up to the manifiold, it reads 10 hg at 1000 rpm
now what?

 

[TJDIV]

What about timing? With a new carb and a new distributor, something could have been set wrong.

 

[IDave]

[quote author=hammer link=board=1;threadid=14761;start=msg144659#msg144659 date=1082836833]
i finally got the chance to use the vacuume gauge.
hooked up to the manifiold, it reads 10 hg at 1000 rpm
now what?

[/quote]
Steady 10 is way too low. Consistant with intake leak.

 

[lowtideride]

ive had a similar prob with my 82 fj60 but mine only happens somtimes...somtimes it runs perfect than others it just runs like crap...ive been chasing the problem since ive had the cruiser. with no real luck.. i mean its running a lot better but the problem is still there...

i was also wondering if it could be the fuel pump..can they bog down at a certain point or is it like it works or it doesnt. im gonna replace the coil and see if it does the trick but its doubtful.. because it feels like fuel prob.. gone thru the following twice with no real help. ( fuel/air filter, plugs,wires,cap, rotor, pcv valve,)

 

[fsusteve]

[quote author=lowtideride link=board=1;threadid=14761;start=msg144719#msg144719 date=1082846889]
ive had a similar prob with my 82 fj60 but mine only happens somtimes...somtimes it runs perfect than others it just runs like crap...ive been chasing the problem since ive had the cruiser. with no real luck.. i mean its running a lot better but the problem is still there...

i was also wondering if it could be the fuel pump..can they bog down at a certain point or is it like it works or it doesnt. im gonna replace the coil and see if it does the trick but its doubtful.. because it feels like fuel prob.. gone thru the following twice with no real help. ( fuel/air filter, plugs,wires,cap, rotor, pcv valve,)
[/quote]

Al, did you check the wire to your fuel solenoid on yer carb, could it be loose enough to cause problems on occassion?

 

[78 One owner]

Sounds like a fuel cutoff valve prob. Got power to it?

 

[lowtideride]

dude to tell you the truth i dont know what tha freakin wire is or looks like or i most def would. im trying to learn as much as i can about my 2f and engines that prob why i spend way to much freakin time on ih8mud

 

[jwest]

[quote author=lowtideride link=board=1;threadid=14761;start=msg144725#msg144725 date=1082847618]
dude to tell you the truth i dont know what tha freakin wire is or looks like or i most def would. im trying to learn as much as i can about my 2f and engines that prob why i spend way to much freakin time on ih8mud
[/quote]

That would be the green connector in front of carb. The neg. wire is connected to the emissions computer. Jumping that wire to a good ground is a test to see if the computer is getting stuck in deceleration mode.

Hammer and Lowtide, I'd also look into egr. A sticking or obstructed egr valve or a faulty egr vacuum modulator (letting in too much early egr), could also cause these symptoms.

 

[hammer]

it just keeps getting better. today, the truck has NO idle, low or high. the only way it will run at all is with me pumping the gas pedal at stop lights, or it will die.
i also notice that i have NO VOLTAGE AT THE CUT OFF SOLENOID. THIS IS STRANG, BECAUSE I HAD IT UP UNTILL YESTERDAY.
BUT THATS KINDA MOOT NOW.
I HAVE HAD IT
ITS TIME TO GIVE UP. I HAVE SPEND 5 YEARS TRYING TO GET THIS THING TO RUN WITH ANY SEMBLLANCE OF SMOOTH, TO NO AVAIL. THOUSANDS SPENT ON NEW PARTS, HOURS IN MY DRIVEWAY AND AT THE SHOP
I I GIVE UP!!!!!
MONDAY MORNING, IT GOES UP FOR SALE.
GOOD RIDENCE!!!!!

 

[fsusteve]

Time to step away from that one for a little while, huh?

 

[Romer]

I had a similar problem. Replaced the fuel filter and fixed the problem. You might double check your voltage reading. Sometimes when you are frustrated things aren't what they seem.

I wish you luck.

 

[folsom50]

Take a break, the more frustrated I get, the worse things turn too sh*t.

Before you get carried away and sell your rig, have you wired the fuel cut soleniod direct to 12V?

Disconnect the two fuel cut soleniod terminals and make two jumper wires that will reach the battery. Hook the two jumpers up to their correct terminals (+to+) and you should hear a click from the soleniod. Start the truck and see if it will idle, might not run too smooth if it's cold.

 

[Ullr]

How do you test a fuel solenoid with only one wire? (1976 FJ40) Is the single wire the neg or pos terminal?

 

[folsom50]

A single wire would be a pos. wire.