Vacuum line is disconnected and EGR blocked off and unplugged. No more vacuum leaks. Smoke only comes back through the throttle body and out of the air box now. I’m going to let the truck idle for a while so it can “re-learn” I guess. From what I’m told it had that vacuum leak for a long time.

 

You will always get a code 31, since the EGR is disconnected.

Will the engine still idle with the IAC unplugged and the throttle blade totally closed? If so, something is still not right. I found one of the big leaks that was causing me problems the other day, it was my PCV valve. The PCV valve is something I never mess with, never have ever considered it being a large player in the engine running. I am now converted. I replaced mine and the idle came back down and I was able to adjust it like its supposed to be. I have read once in awhile that the PCV valve should be a maintenance item like a air filter or something, but I always ignored that. No more for me. I think I am going to replace it in all my other vehicles also.

It must be important also to have the right valve for the right application. They must have different flow rates or something. The one I replaced had to be ordered and came in the next day. You would think with all those PCV valves on all those different engines, they would be like nuts and bolts and they would have something on the shelf that would work, but apparently not.

 

I never thought of checking the PCV either. I’ll look into it.
On the other hand I checked my timing today. I unplugged the little black thingy that stops it from advancing and noticed it was a few degrees retard. My question was which part of the timing mark should 10 degrees be at, the little hole near the bottom or the top where it ends?

Update: I figured it out. Maybe a quick google search before I ask stuff will help lol.

 

Not sure what you mean. Don't you have a pointer or triangle piece? What I do is turn the engine around by hand till the marks are underneath. I then crawl underneath and clean up the marks area till I can read the numbers, and then I take white-out and mark the 10 degree area. I then use the timing light to get in it. This will make a big difference in your idle speed also.

I will also add that I just took apart my IAC, I was going to get a new one but they are kind-of expensive. I figured what did I have to lose, so on the large round end cap I took a hack saw and cut slits in the cap all the way around. I then took a hammer and screwdriver and knocked the cap off. Low and behold that cap is just a cover. Underneath there is a nice brass threaded cap with a slot in it.

I took a screwdriver but could not get it to budge. I then held the housing on the anvil part of my vise and took a hammer and gently tapped all the way around the white metal housing around where the brass part threaded. After that it came right out. It has ao-ring to seal it, and there is a spring and a spool looking piece in there. I was able to clean it up really good, and put a little lube on the end of the spool.

Just in case anyone is curious and wants to take IAC apart.

 

I adjusted my timing to stock specs, 10 degrees BTDC, the truck immediately ran smoother.
Along with that I took off the coffe can looking thing along with the three plugs that are associated with emissions. When I opened the throttle something in that group was clicking so I unplugged and it helped with my issue.
It still persists but it so much better than it was. It does not affect driving anymore like it used to. I will however look into PCV valve and give any updates.
Thanks again for your input guys, I really do appreciate it

 

That coffee can thing is a vacuum reservoir and helps keep the HVAC system "staying put" when you got your foot in it.


In the old days with vacuum wipers if they were on and you hit a hill the wipers would stop till you let up on the gas.
If the wipers had that "coffee can" they would stay working longer.
If you have say the floor vent on and hit a hill the floor would turn off and go to defrost. The can would stop that.
Dave ----

 

Ok so it’s been awhile since I last came here. My issue is still present.... PCV is disconnected and the port on the intake plenum is capped off. Any other suggestions before I take the entire top half of the motor off to fix it?😂 It’s gotten to where it’ll stall randomly when I press the clutch to slow down to a stop. I’m still thinking vacuum leak... but where!?!
Again I just barely crack the throttle open and it stumbles and dies. If I figure out how to upload a video of it I will.

 

Re-connect the PCV, I would go ahead and get a new one. It's a controlled vacuum leak, so I would not eliminate it, that's going to throw it off even more. It expects the metered air from the PCV valve.

Once you get a new valve, with the IAC unplugged, can you turn the idle screw back and the engine will quit? Or does it still run like it did before with the screw not touching the throttle? If it will still run, you still have a vacuum leak/false air coming in from somewhere. If it will quit I think you can call that part good.

 

The truck stalls when IAC is unplugged and idle screw backed out. Blew smoke from my vape into a vacuum line and saw no leaks so all vacuum lines are good. Only reason I unplugged/ capped the PCV was to see if it made a difference, which it didn’t, so I’m totally lost on what to check now.

 

Go for another drive with everything hooked up and stock (except the EGR can be blocked if you like to leave that). Re-cap what it's doing. And is it doing it during warm-up, after it's warmed up, or all the time.

 

 

 

Here are some places in North Carolina that say they have that engine. Some say their engines are a core, so they may sell the intake off of it if you ask.

1986
Engine Assembly
Ford Bronco Full Size 119K 119,000 A 040807 $450 Atlantic Auto Parts USA-NC(Newport) Request_Quote 1-800-950-9443 / 1-252-223-4151 Request_Insurance_Quote
1985
Engine Assembly
Ford Truck 150 CORE W/ROTATING ASSM 21,496 A 11082 $Call Midsouth Auto Recycling USA-NC(Fayetteville) Request_Quote 910-484-7050 Request_Insurance_Quote
1986
Engine Assembly
Ford Truck F150 90 DAY STANDARD WARRANTY! TESTED WELL 16123 $600 Eastern Automotive Inc. USA-NC(Four-Oaks) Request_Quote 1-919-934-4101 Request_Insurance_Quote
1986
Engine Assembly
Ford Truck F150 RECENT RB - BACK OF BLOCK HAS BEEN WELDED &TIMING COVER BROKE -VERY USEABLE 129 $600 Rigsbee Auto Parts USA-NC(Knightdale) Request_Quote 1-919-266-3333 Request_Insurance_Quote
1985
Engine Assembly
Ford Truck F150 00001399 $600 Davis Motor Company USA-NC(Ellenboro) Request_Quote 828-453-7726 Request_Insurance_Quote
1986
Engine Assembly
Ford Truck F150 CORE, SABAS 86F150 $Call Price Auto Parts USA-NC(Knightdale) Request_Quote 1-800-672-9211 Request_Insurance_Quote
1986
Engine Assembly
Ford Truck F150 NOT FOR THE YEAR CARB V BELT PULLYS 5.0L (VIN N, 8th digit),5.0L 6082 $Call Gosnell Used Auto Parts USA-NC(Flat-Rock) Request_Quote 828-696-2500 Request_Insurance_Quote
1986
Engine Assembly
Ford Truck F150 core ------core AA0226 $Call NC Auto Salvage, Inc. USA-NC(Hendersonville) Request_Quote 828-272-0201 Request_Insurance_Quote
1986
Engine Assembly
Ford Truck F150 RDW $Call West Auto Sales & Salvage USA-NC(Bethel) Request_Quote 252-825-1248 / 877-825-1317 Request_Insurance_Quote