Question (1 Viewer)

[SkiLyft]

Hey collective — have had Bleu for almost a year and have been loving the daily drive.

My plan was to drive her for a year and fix things as they came up to make sure the basics were good.

Once she warms up she has always ran a bit differently, it’s tough to articulate but let me try.

Starting — when temps are below 40 takes 2-3 gas pedal pumps with choke out to start, I’ll let her warm up for 3-4 minutes then she purrs along great at 700 rpms when I push in the choke. My drive to work is roughly 10 minutes going 25 mph is, I don’t notice any issues there.

On lunch I run home to let the dog out but it’s the trip back to work where I notice is, the idle will slow way down and she will chug, I have to pump the gas or pull the choke out to keep her happy otherwise RPMs drop to 300 and sometimes she dies. Then she does not want to start.

Plenty of gas in the fuel filter and it’s not visably fouled, carb window is 1/2 full of fuel, I checked that relay that sometimes can burn out (as in when I turn the key to on there is that clicking noise), her running does not change when I uncap the gas tank.

I think it’s a fuel problem as giving her gas solves the issue.

Thought number 1- fuel pump is going? But why would she run fine on relatively short drives? Hmm

Thought number 2 - vacuum leak? I purchased a can of starter fluid and will check that later today.

Last thought — this morning I noted that at the base of the carb there was a bit of fuel, the rubber gasket thing appears to be worn out and broken. See picture, so what is that and could this be the source of my issues?

Lastly what else should I check? I may get a new fuel filter as that’s cheap and could fix the issue haha!

 

[SkiLyft]

Update — sprayed everything with starter fluid and no change in RPM. So thinking the vacuum system is fine.

I’m actually thinking the issue may lie in a poorly tuned carb, when looking at the AC idle up screw it was pretty much all the way out, I screwed that in until my idle increased to ~700 when the engine was warm and drove her hard around the block! When I puked back into my driveway no dip in RPMs and she purred right along!! This is good news but a temporary fix.

I plan to teach myself how to lean drop it and see what happens.

 

[Spike Strip]

That leaking thing is called a 'Secondary Slow Cut Valve' by Toyota. It is no longer available, so if it's leaking you'll have to cap it. Won't affect performance, it's a smog thing. There are threads on the process, but ends up like this.

 

[OSS]

If the idle mixture screw still has the factory cap over the screw head to prevent tampering -I wouldn't mess with it.
Most people have to start fiddling with it because the previous owner screwed around with it.

Turning the idle mixture screw one way or the other isn't going to help an intermittent problem.

 

[lcolon]

My slow cut valve seeps some on hot days but I have never capped it per the JimC fix. Having a working carb fan helps keep the heat down under the hood which may be part of your problem. If the carb fan is not working and you turn the vehicle off when hot, come back 10-15min later, the truck will run terrible due to vapor lock. You will have to drive it for 10min or so to get it to run right again. If the wire going to the heat sensor for your carb fan has burned up and it is not working, just ground it to the chasis. It will cause the carb fan to run 20min or so after each time you stop.

There are 2 screws on the carb, the screw that controls the A/C idle up, and the "real" idle screw that is further back. You can turn the A/C idle up and eventually when it is in enough, it affects the real idle, I would likely back that out and use the real idle screw to get it in place.

In terms of tuning the actual mixture on the carburator, a buddy of mine had a great idea which I have now latched onto to pass smog. He got a wide band o2 sensor and meter off of Amazon. We welded a bung into the exhaust pipe and can put in the o2 sensor temporarily and run the meter off of some clips to the battery. With that setup, you can get the carb dialed in perfectly. Helps pass the smog checks in CA. Once dialed in, all the gear can be removed.

 

[lcolon]

If the idle mixture screw still has the factory cap over the screw head to prevent tampering -I wouldn't mess with it.
Most people have to start fiddling with it because the previous owner screwed around with it.

Turning the idle mixture screw one way or the other isn't going to help an intermittent problem.

I agree with this. I had to mess with my mixture due to a carb rebuild. If it is still capped should work fine.

 

[Spike Strip]

I thought in WA State you smog exempt after 25 years ?

 

[SkiLyft]

Having a working carb fan helps keep the heat down under the hood which may be part of your problem.

Carb fan works and kicks on when I turn the rig off. But good thought!

There are 2 screws on the carb, the screw that controls the A/C idle up, and the "real" idle screw that is further back. You can turn the A/C idle up and eventually when it is in enough, it affects the real idle, I would likely back that out and use the real idle screw to get it in place.

Perfect, this is great info! Knew it was temporary as when I tightened the AC idle screw to get the idle to 700 there were some crazy vacillations in idle when the compressor kicked on.

I’ll back that sucker out and adjust the fast idle screw.

 

[lcolon]

Here are some pictures of the correct screw. Back side of the carburator toward the firewall.

 

[erics]

The AC idle screw only controls the degree to which the idle is increased over baseline (ie bumped up) when AC is engaged... it's located on the front side base of the carb - you can see the idle up vacuum diaphram in in upper left of pic in your first post... AC idle screw controls how much the primary shaft is turned when that diaphram pulls.

just want to make sure you're talking about the right thing... in post 2 you'd said you turned it in to increase idle to 700. If that was done with AC off, then you may get a big surge surprise now when you turn on AC (assuming that system is working).

lcolon said there are two adjustment screws on the carb... actually I would suggest that there are four - AC idle up, regular idle, fast idle, and idle mixture. The fast idle screw is on the back (firewall side of the carb) and sets amount of bump to base mechanical idle when choke is pulled.

 

[cheeese]

correct— idle mix is the one that may or may not be covered, it's on the passenger side of the carb ie under the intake plenum. Fast idle you can see if it's in play or not when you pull the choke thru the driver's window and by how much. If your idle mix screw is still factory covered, then your order of adjustments is regular idle - fast idle - AC idle up

 

[RDub]

This is interesting and timely. I just finished a carb rebuild (Keyster kit) on my '87 FJ60, with manifolds pulled and new Remflex manifold gasket installed. Also fixed the leaking J-Pipe and gasket, etc...Started up and drove pretty well. I went for a couple of test drives about 10 miles each and it ran consistently better than before the work. Then during the third test drive it started doing exactly what SkiLyft described in the first post - won't idle without help, and seems to hesitate some during acceleration in first and second gear. I attached a vacuum gauge to the brake booster fitting on the intake and it seemed to read dead zero. Hard to say, since I could barely keep it running without revving it a bit, which caused the vacuum gauge to fluctuate with rpm. Is this idle issue a common problem? I can't find anything through search, but my wife tells me my search skills are lame at best. Any thoughts?

 

[SkiLyft]

Here are some pictures of the correct screw. Back side of the carburator toward the firewall.

Perfect, those those shots were very helpful!

The AC idle screw only controls the degree to which the idle is increased over baseline (ie bumped up) when AC is engaged... it's located on the front side base of the carb - you can see the idle up vacuum diaphram in in upper left of pic in your first post... AC idle screw controls how much the primary shaft is turned when that diaphram pulls.

just want to make sure you're talking about the right thing... in post 2 you'd said you turned it in to increase idle to 700. If that was done with AC off, then you may get a big surge surprise now when you turn on AC (assuming that system is working).

lcolon said there are two adjustment screws on the carb... actually I would suggest that there are four - AC idle up, regular idle, fast idle, and idle mixture. The fast idle screw is on the back (firewall side of the carb) and sets amount of bump to base mechanical idle when choke is pulled.

Haha you are correct my “jerryriged” fix of adjusting the AC idle yielded some strange results when the AC was turned on. As suggested above I backed off the AC idle and adjusted the regular idle speed. She now purrs right along after being driven hard at 780-800 I feel like she idles better at that speed vs the 680 per manual.

correct— idle mix is the one that may or may not be covered, it's on the passenger side of the carb ie under the intake plenum. Fast idle you can see if it's in play or not when you pull the choke thru the driver's window and by how much. If your idle mix screw is still factory covered, then your order of adjustments is regular idle - fast idle - AC idle up

Perfect, I left the mixture screw alone as I only needed to tweak the regular idle

This is interesting and timely. I just finished a carb rebuild (Keyster kit) on my '87 FJ60, with manifolds pulled and new Remflex manifold gasket installed. Also fixed the leaking J-Pipe and gasket, etc...Started up and drove pretty well. I went for a couple of test drives about 10 miles each and it ran consistently better than before the work. Then during the third test drive it started doing exactly what SkiLyft described in the first post - won't idle without help, and seems to hesitate some during acceleration in first and second gear. I attached a vacuum gauge to the brake booster fitting on the intake and it seemed to read dead zero. Hard to say, since I could barely keep it running without revving it a bit, which caused the vacuum gauge to fluctuate with rpm. Is this idle issue a common problem? I can't find anything through search, but my wife tells me my search skills are lame at best. Any thoughts?

hmm, is there fuel in the carb window when it was struggling after running hard? When you said “dead zero” as in zero vacuum?

 

[Chad717]

This is interesting and timely. I just finished a carb rebuild (Keyster kit) on my '87 FJ60, with manifolds pulled and new Remflex manifold gasket installed. Also fixed the leaking J-Pipe and gasket, etc...Started up and drove pretty well. I went for a couple of test drives about 10 miles each and it ran consistently better than before the work. Then during the third test drive it started doing exactly what SkiLyft described in the first post - won't idle without help, and seems to hesitate some during acceleration in first and second gear. I attached a vacuum gauge to the brake booster fitting on the intake and it seemed to read dead zero. Hard to say, since I could barely keep it running without revving it a bit, which caused the vacuum gauge to fluctuate with rpm. Is this idle issue a common problem? I can't find anything through search, but my wife tells me my search skills are lame at best. Any thoughts?

After I rebuilt my carb, my idle mixture was way off, and it caused it not to idle. That wouldn't explain how it ran good at first though. I bottomed it out gently and then turned it about 2.5 to 3 turns out to get it running. Did the lean drop method a few times, which is in the FSM or searchable on here, making sure the timing was adjusted as well each time. You're in Boulder? Made it through smog yet?

 

[RDub]

I meant the vacuum gauge read zero when I said dead zero, sorry. There was fuel in the carb bowl, and it ran reasonably well above about 1200 rpm. Today I retorqued the manifold bolts, and bumped it up to 28 ft-lb (calibrated torque wrench, so likely very close). The Remflex recommendation is 20-25 ft-lb, and I went with about 22 when installing it out of fear of cracking the gasket during initial torque down. When I retorqued today the lower-most forward bolt seemed to take some rotation, while the others basically just broke loose and immediately clicked the torque wrench. Static friction may have been the culprit on those. I also replaced the large vacuum line leading from the HIC valve in the air cleaner housing. That line goes to a "T" in the PCV line, and that huge line goes to a rather large diameter tube that is part of the EGR inlet on the intake manifold. It could have been that, or partly that. Vacuum at idle went up to 16 from the 15 I saw immediately after the gasket replacement yesterday. I will drive it around some more, give it some hot/cool down cycles, and see how it goes.

It passed smog when I bought it about 6 months ago. It had failed twice before, and the previous owner sprinkled some magic E85 on it and then it passed the third time, with the knowledge that I needed to get rid of the rest of that juice, replace the bad air pump and take care of several bad vacuum switching valves, among many others things as it turned out. I bought a rebuilt air pump from BZ Rebuilders in Canoga Park, CA.

 

[RDub]

Chad717...do you happen to know what your 60 has for vacuum reading at idle? Being at a similar elevation...

 

[Chad717]

Chad717...do you happen to know what your 60 has for vacuum reading at idle? Being at a similar elevation...

Mine stays right around 18, but I just had the engine rebuilt. Still haven't been able to pass emissions however so let me know how yours goes.

 

[RDub]

I'm good on emissions for another 4 1/2 years. Passed emissions when I bought it, as described. Collector plates now, so every five years. It's a project, so no issue staying below the maximum miles per year. Did you have the intake and exhaust manifolds resurfaced? I'd be interested in finding a shop or two that have competence in doing that.

 

[RDub]

I suspect among other things the emissions computer in mine is not working correctly. The EGR system does odd things, and there are other symptoms that are more or less in line with the computer. IS yours working properly?

 

[Chad717]

I'm good on emissions for another 4 1/2 years. Passed emissions when I bought it, as described. Collector plates now, so every five years. It's a project, so no issue staying below the maximum miles per year. Did you have the intake and exhaust manifolds resurfaced? I'd be interested in finding a shop or two that have competence in doing that.

Ahh sorry, I misunderstood and thought it had passed for the previous owner and not you yet. I did not have the the manifolds resurfaced, I got a new intake manifold and headers for the exhaust. Mountain High Performance in Arvada did my engine and they are pretty knowledgeable about cruisers even though it’s a diesel shop. I’m sure they could resurface your manifolds.