Can you take a look at this photo and tell me if those two holes in between the bolt holes should be open? Is that what lets the gas go to the egr valve? So basically mines blocked off? Think that could effect my gas mileage, or do you think I've effectively blocked off my egr system and so it wouldn't affect performance? Or should those be blocked off? I'm not sure.

 

thats the tbes that bolt to the manifold, run around thye back side of the block, to a valve under the intake and back to the airbox. It provides a warm air pulse occasionally, i think to reduce nox emissions during warmup. Ive run with these connected, disconnected and never noticed a change in mileage. You can get block off plates and eliminate it but where I live its a big no no for state emission inspection

 

Ok, right, the egr system (exhaust gas recirculation). So they should be unplugged I guess. Must have totally blocked themselves off with carbon. Well, until my egr vacuum modulator is replaced (it's plugged up too) I guess there's no reason to worry about this. I'll fix them both at the same time in a couple months unless anyone else has some input?

 

just remove the EGR .. it is a fuel consumption HP robber and a waist of time .

 

actually the egr valve cools cylinder temps and increases gas mileage and those are air (air injection recirculation) holes for the lines that r supposed to bolt up to them and yes u can block em off if u have to if u no longer have the pump hooked up however the emissions police might have a thing or 2 to say about it if u have to get it inspected/smog tested

 

"on paper " yes ... but in the real world , as pictured here .. they clog , and are not practical in the long run .

 

of course after so many years they will plug eventually that is where preventative maintenance kicks in and as seen here is a separate system tho they both r emissions related

 

hint preventative maintenance but they do help out in the long run tho i have mine blocked off too lol not egr, air

 

Ok...just curious though, if for now, until I can clean that (if I decided to) what do I need to plug on the intake end of the engine to disable it? Just find what supplies vacuum to the egr and vacuum module and plug them? I'm leaving for a trip Thursday, and don't have time for either fixing it or actually blocking off where the egr bolts to the head, so what should I just block off to disable it temporarily? Want to get good gas mileage..

Like I was wondering before, does the fact that it's clogged at the exaust side effectively "block it off", or since it's blocked off there, but still trying to work on the intake side, is it causing performance issues? Any short-term-fix advice would really help!

 

now r u talking the egr or the air system in the picture?? do u still have the lines and the pump??

 

Yeah, I've had the egr and vacuum modulator off to clean them & get it all working, but it didn't help any. Figured I'd look back through my rebuild photos to see if I could find anything on the exhaust end and found that photo. So I've still got the egr valve and vacuum modulator hooked up. So knowing that I have no way of getting a block-off plate for the actual valve before my road trip, what hoses can I plug to disable it for now, until I decide whether I'm going to plug it up or fix it?

We don't have emissions testing here, but I still will consider fixing it when money allows. Thanks for the help!

 

if u cleaned the egr and the vacuum modulator filter up whats the problem?? is it sticking or what have u checked the vacuum lines to it?? as far as the air system ud need to pull the pump off disconnect the vaccum hose from the reed valve however u will have a nasty exhaust leak till u plug off those lines and as far as the egr goes disconnect the main vacuum lines (modulator lines or the lines running to the carb) block em off and that should prevent it from opening if im not mistaken tho i have been wrong once before

 

in fact i think i have a complete air and egr system if yours is to far gone however it is deff a well used item lol

 

Ok thank you. My vacuum modulator is (I think) the problem. It's plugged up. If it was just the exhaust end that was clogged I'd just clean it out, but I need to replace the modulator, and it's pricey. So I'm wanting to just prevent it from opening for now. I guess I'm also curious if the fact that it's blocked off with carbon at the exhaust end will have any effect on my truck's performance/mileage. If not I just won't worry about it for now, but if it does effect it, I'd like to just plug off whatever makes the valve function, for now.

So since I don't have a block off plate for the valve, I'm just wondering if for now I can just plug a few vacuum lines and bypass it for now? I don't know (yet) how the whole system works, so I don't understand how the reed valve and all that ties into the egr system, I just know I have some performance issues and if they are egr related, I'd like to just keep the valve non-functional for now until I can fix or completely tear all that stuff out.

So for right now, to not have it effect my trucks mileage etc., is there a way to just plug off some vacuum hoses and keep it from functioning?

 

the reed valve is not part of the egr system it is part of the air system those lines that attach to the manifold are also part of the air system not the egr sounds like what would b easiest would b go to a parts store pickup a haynes repair manual for your truck give it a good read over it will help

 

yep just plug off the vaccum lines going to the modulator and the egr however if it is stuck open it will do u no good

 

Ok thanks. I don't think the valve is stuck, I could move it pretty easily once I had cleaned things out, just a clogged up modulator and exhaust end obviously. I'll trace some vacuum lines and see if I can figure out what's what and plug some things off. Thank you.

 

Reading back through I see that you seem to be saying that the holes that are clogged with carbon in my exhaust manifold don't have anything to do with the egr system? Where does it get the exhaust gas from then? Where it attaches to the head? I have a Haynes and an online 1985 FSM, and they don't describe the entire egr or exhaust system. I'll look back through but I don't see the tubes that are blocked off by carbon on my exhaust manifold anywhere in there, or something that describes all the parts of the egr or how it works. I'll look harder though I guess.

 

go to the index in the back of the haynes book look under emissions find the page number scroll through and bingo there it is altho i doubt it has a pic of the tubes that runs to your manifold just a pic of the pump and reed valve and related vacuum hoses it will tell u the basic operation and the devices


now to clarify something ru trying to block of those lines or the egr valve seeing as how i got a little confused with the repetition lol

 

Well, I was thinking those lines were part of the egr valve, but since they aren't, I'm forgetting about them for now. Clearly they are already blocked off, so there's nothing I need to do there until I decide to take the time to get it all cleaned.

As far as the egr, I will either pull the valve and make sure it isn't stuck open, reinstall then plug the vacuum lines, or see if I can find something in the garage to use as a block. I saw somebody just cut a beer can, put bolt holes in it and used that as a "gasket" and reinstalled the valve, so that blocked the hole. I will do one of those two and see if that fixes my terrible gas mileage. Then when I can afford it and I have more time I'll start cleaning and replacing things.

I've been thinking for a while that my egr may be one of my gas mileage problems, and since I thought those air tubes were part of the egr, that's why I posted that photo.

Thank you for the help!