Yeah, thanks Franklin. I was reading that thread just now and his miss was opposite mine he had steady miss at high idle and cleared up in drive. I don't miss until in gear and warmed up. Why would I get vac at idle? Isn't ported vac on 2150 front right side next to air bleeder? I think since it's only when warmed up it has to be after the ported vac switch and makes me suspect egr/purge/tvs/smog pump influence.^#$&*^I try pulling hoses from tvs and plugging and it helps but then doesn't. Could brake have vac loss when holding the truck at a light? It seems to only happen when I idle in gear.Another thing yesterday had a moment of ;loss of vaccuum in steering for a few seconds. Like power steering had a vac loss.

 

All the vacuum diagrams I'm finding have the distributor hooked to manifold vacuum. And I have no idea why, will look into it when I get home.


S port from the first picture I posted is ported vacuum. It runs through the pvs so that those components hooked downline only open during acceleration and after the truck is at operating temperature, i.e. egr.

 

I'm going to try to see if idle down will remove vac at idle on ported line. Also verify advance not leakin.

 

The throttle may be open too far, uncovering the port on the ported vacuum hose connection. The first thing to do, I think is what you mentioned in your last post, is to take the line off the distributor and plug it, and leave it off and test drive it for a little bit. If your problems go away you know it is something to do with the vacuum to the dist.

The have so many variations to these vacuum systems, and I have never seen a blow by blow description of how some of these systems work. They all seem like band aids to me, adding stuff here and there and making it come on at different times, just to pass emissions testing. There is a lot of stuff in there to fail, and it's hard to figure out if it's bad or not, and it's hard to figure out how to order it and where to get replacements even if they are available. All the engines I have ever messed with ran better when I hooked them up the simple way, and I think would have passed emissions with some careful tuning. I always kept all that vacuum stuff, just in case I had to hook it back up with little ball bearings in the lines to plug them off and make it look good and still keep the engine running decent. But in my area when they lift the hood, all they mainly look for is the smog pump and that it has a belt on it.

 

Before you decide to rearrange vacuum lines, let's have a little faith in the Ford engineers and make sure it's hooked up how they intended. Then we can diagnose what the problem could be. I'm trying to learn as much as I can about the emission systems from this era. If you can spare the time and have the interest I will help you work through yours if you will post detailed photos of your vacuum lines and your emissions sticker if it's still readable.

 

Hi there Have a look at that diagram I posted above 54-K-R0 is the calibration. That's a scan out of the manual and it's what it's supposed to be 49 state but I';m in Cali where restrictions suck and these trucks should be exempt if they are maintained well enough to still run. I'll have pics tomorrow Do you know what a delay valve looks like?

 

The Distributor check valve(replacment) for my truck looks like this https://www.rockauto.com/en/catalog/...eck+valve,4950

 

 

Have you ever had anything inspected in Ca? If so, how did it go and what was your impression of the whole thing and who was doing the inspections? A lot of the guys in the garages here in Va are just like most of us, even though they are mechanics they do not know all the little ins and outs of these emissions systems. Think about it, Ford had hundreds of different systems on their vehicles, cars, trucks, etc. And then you have GM, Chrysler, Toyota, etc. All that stuff is different, I venture to say they cannot keep up with all of it and know what is right and what is wrong.

 

Yes, Franklin It is a big pile of bull sh&*^. The state has most of the control over this. The guys that test basically are suppoised to see that the sticker is there and being complied with. None of the 40 year old vehicles or 30 or 20 will be right. Ford Parts guy just told me if it's over 15 years old they stop making it. They said might as well forget their number. They need to update the exempt list of years for cars that need this. I'm paying 140 registration each yeAR. As well as 60 just for testing everyother year. To pass though, I've had to pay what the shop will charge for getting me to pass. It's a crooked system in a crooked world. I've failed for everything you can fail for. I've also failed for gas caps, a vac line not capped on a 2nd nipple of a dual advance. I was told the oil change is crucial to pass. I was also told to drive it hard right before you come in, another guy said that will also cause a fail. It's a precarious balance of components not quite the same trying to do to things the same they tried before. Like you said, a bandaid. Keep it cool if it gets hot, block this, bypass that, delay a spark, delay a vacuum, delay a person who waits to be tested by making him schedule an appointment with the 'referree' They're booked til july. Meanwhile, go get temp tags and plan on going through all the oil change and timing to the sticker again. When I pass, it takes 2 weeks of messing with it to get it to drive like it might make it somewhere. Then, I have 2 years to hope the state legislature votes the 1980 exempt. Almost happened 2 years ago. Next car zI buy will be exempt. Guaranteed.

 

Thank you cbutitus. I have one of those. cool. Pics taken but not here yet. Advance moves and holds.

 

Herre's what I got under there

 

The above photos shows my manifold vac line that was hooked to a vrv along with a line to the carb. I was trying to eliminate vacuum at idle on the advance port. So I have it running direct to right front of carb. The little tree up top is been eliminated and I just use a tree port. I have the heater stuff up by the firewall in the corner mostly plugged. as they are withered into dust. The tank vent, the vent bowl, and the s port all converge at the purge valve with a hose from the smog pump also. The pipe in back for secondary is brand new. The tranny hose simply loops up from the tree and back down onto the steel tube in back. The stove plumbing is the line in the sleeve in back as well as the line going to the exhaust from the choke. The shiny metal tube thing is a manual choke cable not used but was considering it last year before replacing choke linkage.

 

I put my old choke cap back on last night and it likes it much better. Still serious miss every 3-4 seconds for 3 good hard shakes in R or D. With brake applied. Heading down now to see if it still does it with out the booster filled.

 

I'll look more at those photos when I get home. Just to confirm, you have California emissions?