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Hey yall, new here, can yall help me identify some of the old smog components. Someone ripped out the stuff and half hazardly put a nice Edelbrock carb on.
It runs good idling, but seems to suck gas and be under powered while driving. I will likely be rebuilding this thing. What can I do to "fix" this. Do not want to replace the smog stuff, just finish their job.
I know I will need to set up the system to run differently without the smog stuff, such as a different PVS valve, EGR, and such, not really sure what I am looking at here though to be honest.
You can see they just cut and went to town. Kinda want a nice setup like another 85 Lariat I saw on here. i just put a new starter, dist cap, plugs and wires in. Just getting started now. Thanks everyone.
You have a mess. Without removing the emissions stuff but just disconnecting things you can't really know what you have. But, I'd guess that they left you with the computer controlling your distributor. If so, that'll kill the power and MPG.
Does your distributor have a vacuum advance? If you don't know, post a pic of the distributor.
Indeed it does appear to have that feature. I just put a new cap on. Is it possible to move backwards now? Always had fuel injected Chevys growing up, so bear with me. All I have is a Chiltons manual and this resource.
It does start and idle much cleaner now. But still seems extremely underpowered and that would explain why.
I wanted an older vehicle to restore and not have payments. I got the truck for cheap so I cant complain to much.
Ok, you do have a vacuum-advance distributor, which means the computer isn't controlling the advance. But, we need to drop back a step as I don't even know what year your truck is. I need to know because if it is an 84 - 86 351W it could be an HO and they came with a 4bbl carb and DS-II ignition. Having said that, from what I can see I'd bet it wasn't an HO.
That's the HO air cleaner and it would have had a 4bbl Holley carb. And I would LOVE to have some good, close-up pics of that lid. I'm re-creating the font for Dad's truck but it'll read "6.6 Liter 4V H.O."
So, now we know what you have. And, if it was working correctly you should get 12+ MPG and have reasonable power. What MPG do you get? Have you checked the timing? Looked for vacuum leaks?
Timing is spot on, just took it to a shop owned by a church member and one of his mechamics has a similar model f250 and tuned it up for me. He said he also repaired A vacuum leak he found, though I am not sure where.
I am a bit concerned with all the open vacuum ends, including that old broken looking port behind the carb. What is that?
in my fourth picture there is a silver canister on the back of the carb with an open port and the above mentioned item further down the firewall
That big silver thing near the firewall is the air check valve. Air from the smog pump goes in there to the heads to be mixed with the exhaust. Its not a vacuum fitting. If the check valve isn't broken its not really hurting anything being disconnected. If its leaking you could possibly get exhaust fumes coming out there.
In the 4th pic the unplugged port to the right is the vacuum connection to the EGR valve. So the EGR valve isn't working, which is ok - assuming the valve isn't leaking exhaust into the intake. Exhaust Gas Recirculation valves were designed to admit exhaust gas back into the intake under certain conditions to lower the emissions from the engine. Properly working they don't degrade performance, but they don't work properly all the time. In fact, they can stick open such that they admit exhaust gas all of the time, and that will hurt performance and drivability.
The only way to know for sure is to pull the EGR valve and check it. And if it is leaking you can have a block-off plate installed. Or, just have a block-off plate installed as the valve certainly isn't working with the vacuum not connected. And, judging by all else I see disconnected, making the EGR valve work would be a major project that probably isn't worth it.
The other thing in the 4th pic is the broken end of the AIR manifold. Air Injection Reaction was a system that injected clean air into the exhaust stream so the catalytic converter can burn in-burned hydrocarbons coming out of the engine. In this case the AIR pump pushed air through the connection you see and into the rear of both heads. There's a passage drilled all the way through the head and connecting with each exhaust port such that the air went into the exhaust stream after the exhaust valve. But your AIR system has been neutered, probably by the removal of the pump that sat above the alternator. But the manifold that connected to the rear of the heads has been left in place. That's ok - if and only if the check valve in that bulge is working. So, while the engine is running, place your hand above the opening to see if exhaust is coming out. If not, all is well.
Ok third picture, take the vac hose (red arrow) that is on the drivers side port of the carb and swap it to the passengers side, also replace the "plug" (yellow circle) that is currently on the port your are swapping to, I can see it is destroyed. The port circled green should go to your PCV??? Or it can run of the back.
Also go buy you a kit of the vac "plugs, replace all the hose with bolts and eliminate variables, vacuum leaks will cause utter havoc on a system, then the owner goes through and starts replacing all kinds of parts when the only problem in the first place was leaks
On this Pic, my bypass valve is also plugged with a bolt (red circle). Gary pointed out that your EGR isn't even hooked up (green circle) no vac line on it, additionally it appears that the PO "blocked" the EGR with a metal spacer where it bolts onto the space (yellow circle). At least that is what I see.
04-26-2015, 06:04 PM
