fresh desmog, no start. DIAG (1 Viewer)

[masonbarnard]

timing light and ics have not arrived in the mail yet. but

Right now the vacuum reads 15, i drove it around for twenty minutes and it felt great.

- even though i do not have the timing light yet, when i turn the distributor the vacuum will not get higher then 15.

 

[gregnash]

When you say it won't idle below 1000, does that mean that when the idle speed screw is backed out:
1. the idle speed just stays at 1000, or
2. the engine idles down and dies?

On the ICS, do not install a chinesium ICS from CCOT, they aren't made right.
Since it is sorta idling without power to ICS, remove ICS, see if the end is already snipped off the ICS. If not, then hack end off ICS and reinstall for troubleshooting purposes.

Also, there's little point in troubleshooting the fuel & vacuum issues when the timing is still not set correctly.
Here's a good quality made in US timing light for ~$20:
vintage sun pro timing light with power cord pn # cp7515 | eBay

@FJ40Jim Do you have another recommendation for an ICS? The CCOT one is the only that I have been able to find available anywhere.

 

[FJ40Jim]

Since they never fail, I recommend a good used OEM one. The chinesium ones don't control the size of the orifice, because they don't know it is part of the idle jetting.

 

[masonbarnard]

Okay, I adjusted my timing using a timing Light. timed to bb.
Found vacuum to drop from 15 to 13. Very steady at 13. the more clockwise the distributor, the higher the vacuum.

Why is my vacuum at Idle so low, and why was it so steady at a 19 one week ago.

Car starts instantly, but now it won't idle. No power to ICS, found engine fuse burnt. maybe i wired the new ICS backwards lol. the new ICS works. clicks at battery

. Vacuum is now 13 when it was idling. It doesnt sound as healthy as it should but it also isn't "tuned". the valves are quiet and there's no knock. My muffler is leaking and there's a test pipe.

 

[gregnash]

If you are timing to the BB then that is only 7* if I remember correctly. If you are desmogging then the trucks like to be around 10* (@FJ40Jim correct me if im wrong).

For the timing are you using the procedure in the manual? Also, just takes some tinkering you are going to probably have to go between timing then carb adjustments, timing, carb adjustments, lean drop, etc.

 

[masonbarnard]

 

[gregnash]

I think I can hear a vacuum leak but not quite sure... You have checked all lines to ensure nothing is cracked correct and that your routing is correct? Also, maybe try closing off the AC Idle Up port just in case.

 

[NeverGiveUpYota]

14 degrees is what Georg of Valley Hybrids has said... And the caps on the upper ports of your carb. check them. I just pulled my carb and the two ports I have capped... the rubber was totally cracked.

 

[masonbarnard]

Okay.

How do I know it's at 10 or 14 if that part of the flywheel has no markings?

My timing light has an advance knob, that I kept at zero. should I turn it to 10 or 14 and then what?

 

[NeverGiveUpYota]

Did you find the BB and tdc line? Marked them in whiteout?
I'll quote what I was told....

"Rotate the distributor either way until the BB lines up the the pointer. 7* btdc. Yes they like to be more advanced, but wait until you get the dissy re-curved for that, it may ping. 7-10 is fine for now. You can try 10 and if it pings back it off a bit.

THIS is where the advance feature on the timing light comes in handy: you can set the advance on the light to 10 degrees and when you point it at the flywheel and set to Zero, it's actually 10*.

But I'd recommend set at 7* (on BB) and go from there. Once the truck is dialed in and running well, you can tweak it a bit."

 

[mwebfj60]

You have 2 lines hooked to the gas filter, where are you hooking them up? I am hearing a vacuum leak.

 

[mwebfj60]

You have 2 lines hooked to the gas filter, where are you hooking them up? I am hearing a vacuum leak.

Found it, going to cab. Lots of reading.

 

[Output Shaft]

The sound of the engine (sort of stumbling) when you walked to the back sounds like a 2F vacuum leak. Very familiar sound. When my EGR valve occasionally doesn't seal completely (aka vacuum leak) my engine will sound just like that until I show it whose boss.

I know you don't have an EGR system hooked up, but your engine sounds like, and your vacuum gauge is telling you, there is a significant vacuum leak somewhere.

 

[masonbarnard]

Yeah there is lots of reading. This thread is a legendary compilation of doodoo. I'm sorry humans, hopefully it will help some kid In the future.

Replaced the blown engine fuse a and now it idles again with the new ICS. The idle is great and throttle response is amazing.

Vacuum at idle is now fluctuating between 19-16, stays relitively steady at 17. I haven't adjusted valves yet but they sound pretty good. There use to be more exhaust smoke now there's none.

I'm on the right track.

Also there's a occosional pop from the manifold while warming up. I'll try tightening the exhaust manifold plate, and EGR inlet into the intake. I never double checked the work on that.

 

[masonbarnard]

I've driven it about an hour so far and here are the problems.

1) when the engine is warmed up, the idle screw has no effect on the idle. I noticed because once the car is warmed up, the idle raises to 1000, and won't come down even with idle screw out....

2) Vacuum is intermittently good. Sometimes it's at 19, sometimes it's at 15.

3) When I shut the car off for a couple minutes, then turn it back on, it will start right up, but hard to idle without choke

4) am I suppose to do anything with the valve cover breather hole

5) I haven't touched the charcoal canister, should I?

Edit: there are like 5 exhaust leaks after the test pipe.

 

[Output Shaft]

When the engine first starts up cold, the vacuum will be less until it warms up on an older engine. But the vacuum shouldn't be high one moment, then drop 4" a few minutes later. It should always be stable at idle depending on the sensitivity of the gauge.m
Your engine is sounding pretty good. Not perfect, but not horrible.

Check the gas pedal linkage going to the carb. Disconnect it and see if the idle speed drops.

 

[masonbarnard]

When the engine first starts up cold, the vacuum will be less until it warms up on an older engine. But the vacuum shouldn't be high one moment, then drop 4" a few minutes later. It should always be stable at idle depending on the sensitivity of the gauge.m
Your engine is sounding pretty good. Not perfect, but not horrible.

Check the gas pedal linkage going to the carb. Disconnect it and see if the idle speed drops.

I'll get it to 18-19, drive around, turn it off, and when I start it up again the vacuum will be 14-15

 

[Output Shaft]

For how long? Will it eventually get back to 18-19?

 

[FJ40Jim]

On the idle adjustment, there are 3 idle speed screws on the carb. The base idle speed (rear of carb, in the iron throttle body), choke idle speed (rear, in the linkage), and AC idle speed (front of carb, on primary throttle shaft).

First, make sure you are adjusting the base idle screw, not one of the others. If the base idle will not lower the idle speed, then check that one of the other 2 screws is not adjusted too tight, holding up the idle.

Perhaps @Output Shaft can post the factory drawings of adjust screw locations.

 

[Output Shaft]