Starts and runs only on choke.

[lehiguy]

You have a clog in your idle circuit. I think a carb rebuild is in your near future, or better yet, throw that POS as far as you can and get a Weber, a header and a fluid heat riser. That was the best thing I ever did to my I6 until I replaced it with a V8.

 

[BulletHead]

update: havent had a lot of time to work on it but here it is...

ICS (idle circuit solenoid), FCS (fuel cut solenoid), im not sure if thats exactly what they stand for but anyways, are they the same thing just different names? is that the small round cylinder on top of the carb that has the connector coming out of it? it seems to run on choke... but as soon as i turn the choke off, it stops running.

i think i read on one of fj40jim's posts that maybe the issue may be that there isnt a ground signal coming from the ECU. so to aleviate that issue, can i permanently ground one of the connectors right to the battery? i think some people have done taht and it seems to work. i did ground the FCS with a wire and it clicks, which i guess means its working? i will try to test this theory when i get home tonight and report back.

i initially thought i had a bad carb and needs rebuilding but i put on a carb that i bought from a member here, which was rebuilt a couple of years ago and its teh same issue which leads me to believe it may be the signal from the ECU. when exactly does that ECU signal get generated and transmitted? when the choke is turned off?

 

[bridges]

Might want to try some more simple stuff, it's tough to get a vacuum reading from a gauge when it won't idle and with the choke pulled it'll likely look great at 1500 rpm.

Idle it down as much as possible pushing the choke in as far as you can without the engine dying, then grab some carb cleaner and spray the vacuum lines/connections, when/if the engine revs from the spray you've likely found your vacuum leak area and can narrow it down from there.

 

[D'Animal]

WOW!

You have been working on this for about a year.

I would recomend you join your local Land Cruiser or TLCA club and have one of the members come by and look at it.


I have built complete vehicles starting with a frame in a years time.

 

[weak-link]

did you make sure your tire pressure was at the factory recommendation?

how about your clutch, is it adjusted per the FSM?

 

[BulletHead]

WOW!

You have been working on this for about a year.

I would recomend you join your local Land Cruiser or TLCA club and have one of the members come by and look at it.


I have built complete vehicles starting with a frame in a years time.

time is the biggest factor here, i just havent had a lot of time to work on it. been real busy with travel and work, and put in some troubleshooting time here and there. i should get it running by the end of the summer. hopefully.

 

[D'Animal]

All the more reason to join a club.

Most of the members in Central Valley Crawlers travel for thier job. We have wrenching weekends and get a ton done on a lot of rigs in one or maybe two days.

time is the biggest factor here, i just havent had a lot of time to work on it. been real busy with travel and work, and put in some troubleshooting time here and there. i should get it running by the end of the summer. hopefully.

 

[BulletHead]

so i should have 12 volts at the FCS plug coming from the ECU with the choke on or off?


if anyone is close to medford, near Tufts, and can help me diagnose, please let me know, id appreciate the help.

 

[Wile E Coyote]

Yup, I'll fully agree it's time to call for reinforcements. Just going by your boston locale in your sig line, the following would be a local chapter to solicit for some extra hands. MA/NH- Yankee Toys - IH8MUD™ Forums
Get that beast road-worthy before winter, lord knows you aren't gonna feel like tinkering on it knee deep in white stuff, and it'll sit until next spring, hehe.
It would seem the other carb ruled out my clogged carb theory, but to be clear, you were running fresh fuel through the replacement carb, right? If not, pull a shadetree mechanic trick by holding a jug of fresh fuel high over the motor and gravity feeding it directly into the carb. It won't feed the engine well at WOT, but would let it idle just fine, eliminating problems like restricted fuel delivery from clogged filter or fuel hoses, weak pump, etc.

 

[drtstreet]

check the intake manafold connection to the engin, my 60 was doing the same thing and i took it to a shop and that is what the diagnosis was and it runs like a champ now.

 

[cruiserland]

is the ground wire from the cutoff solenoid burnt/connected properly? a bad connection will do this too methnks

 

[BulletHead]

FCS or ICS connection is connected, im pretty sure its connected properly too. i did some, or tried to do some diagnosing today. here are the results.

while its running in choke mode and i disconnect the FCS connector, the motor slowly dies. i guess this confirms that the FCS is working properly?

also, as i take it off the choke get it to run at about 500rpm with my foot on the accelerator it barely runs and gradually dies. but one thing that i tried is i turned the AC on and voila! it wants to run at 1300-1500 rpm and i can take my foot off and it will stay at about 1300-1500 rpm. as soon as i turn the AC off, it dies in about 5 seconds.

does this confirm that there is something wrong with the idle circuit?

 

[bridges]

....also, as i take it off the choke get it to run at about 500rpm with my foot on the accelerator it barely runs and gradually dies. but one thing that i tried is i turned the AC on and voila! it wants to run at 1300-1500 rpm and i can take my foot off and it will stay at about 1300-1500 rpm. as soon as i turn the AC off, it dies in about 5 seconds.

does this confirm that there is something wrong with the idle circuit?

I don't think so, this probably confirms your idle circuit is working as expected since the A/C on triggers the higher RPM like it's designed.

Turning on the A/C is producing the same results as pulling on the choke - you're forcing higher RPMs which is probably masking a vacuum issue.

 

[landtank]

the fact that it idles with the AC on I think I know where the problem is. Forgive me but it's been 12 years since I had my head in my FJ60 but the idle circuit has 3 positions. You have the idle postion which controls the truck's idle when idling. You have a second position with controls the idle during AC use, this is a higher idle. And you have a third position which actually drops the idle when you turn the key off to prevent dieseling. I believe you are in that third position when you start the truck and that is why it's not idling correctly. I can't remember if it's vacuum or electric which controls that. Again this is coming out of a 12 year haze so cut me some slack guys.

 

[BulletHead]

the fact that it idles with the AC on I think I know where the problem is. Forgive me but it's been 12 years since I had my head in my FJ60 but the idle circuit has 3 positions. You have the idle postion which controls the truck's idle when idling. You have a second position with controls the idle during AC use, this is a higher idle. And you have a third position which actually drops the idle when you turn the key off to prevent dieseling. I believe you are in that third position when you start the truck and that is why it's not idling correctly. I can't remember if it's vacuum or electric which controls that. Again this is coming out of a 12 year haze so cut me some slack guys.

son of a gun, id be lucky if i could remember stuff for 12 days man...

anyways... so it sounds like i have a vacuum leak which is causing me to fall into the 3rd idle circuit position? looks like ill have to track that vacuum leak somehow. wish me luck.

 

[landtank]

I think it's something like a electric coil that move the plunger into the idle position and a vacuum hose the moves it further to the high idle (AC) position. The anti diesel(low position) is both off. Just look at the idle screw and have someone star the truck. The reason it idles with the choke on is that a stepped cam mechanically moves into a position to raise the idle.

 

[BulletHead]

ok, thanks, ill play around with the idle screw tomorrow. will this also affect the idle speed when the AC is on?

 

[landtank]

if it's what I think it will raise your AC idle when fixed. You first need to confirm that the system is operating properly. Going in and adjusting the screw might get it to idle but if that first position isn't being made your setting yourself up for a dieseling problem when you shut off the engine.

The more I think about it, you should see the plunger move out when the key is in the on position. Check the plunger when the truck is off and then just turn the key to the on position and see if the plunger moves out. If it doesn't then you have an electric problem in the circuit I think.

 

[landtank]

I changed my mind on thsi one and I think it's a VTV issue. Follow the vacuum line that is attached to the idle up assembly and you should find a round plastic widget with a colored band on it. These were a major pain in my ass as they would get clogged and stop working. I would get a length of hose to replace the widget and both pieces of hose on it's end.

 

[BulletHead]

Rick,
so you are saying to replace the VTV with a single piece of hose? is this the one you are talking about? i did notice the CB diaghragm was moving if i were to squirt some carb cleaner into the carb.