Hi all, So in the most recent episode of figuring out why my Maverick runs so poorly, I came across all the dodgy vacuum "deleting" the previous owner did. With most of it sorted, I still have one question. I attached pictures, but what are these holes supposed to be for? They run into the intake just after the carb, so I thought maybe it was an EGR port, but I have no idea. I put up a picture of the charcoal canister too, and it's two missing ports, which led me to think that maybe it's an emissions thing too. Would this be something I can just block off? I was also thinking that this could be why the cabin always smells like fuel and exhaust (besides the likely exhaust leak).
"I was also thinking that this could be why the cabin always smells like fuel and exhaust (besides the likely exhaust leak)." this sounds more like bad seals on doors, windows, trunk or cowl...
Wide open EGR ports will definitely given you a lot of stink and noise... You have found your exhaust leak. As for the charcoal canister The center port is a vent, the off center one should have a hose going to the air filter assembly.
Likely all of the above I suppose I could get another EGR valve, but would it really matter if I just made up a blocking plate for that port?
I used a pre-emission carb mount from a 250 to fit my 250. The 170/200 mount does not fit on a 250...wrong bolt pattern. If you need a 170/200 adapter I could sell you the one in the pic
I'd get rid of it. The EGR functions only during part-throttle cruise conditions. It is non-functional during idle and wide open throttle conditions. It also creates a lot of carbon build up since exhaust is being recirculated into the intake.
Questions on EGR & other emissions items give me a laugh about how times have changed... Back in the day first thing us car guys did was pull this stuff off or at least render it inoperative... Wasn't needed last year, no chance it's needed now(of course last year Ford had been using EFI for around 33 years)... Also was pretty much known these archaic emission controls lessened fuel milage and often caused drivability issues... Pop bought a new '79 Cougar from my uncle's dealership up in WVa... First thing my uncle did before it left the lot was jam a small steel ball inside the hose leading to EGR valve...
To be honest, the engines from the 70's pollute like crazy compared to the engines today, but it was the best they could do. EGR or exhaust gas recirculation was developed to lower combustion gas temperatures to lower the production of NOX, or compounds of nitrogen. The X represents various numbers as there are numerous different coumpounds. NOX was a significant source of airborne pollution in large cities such as LA. As Crazy Larry pointed out, the EGR doesn't function at wide open throttle, so you can't blame the EGR for taking away horsepower from your engine while stomping on the go peddle. Having said that, these were mass produced engines and the EGR helped lower pollution across cities in North America. Will it make any difference if all the Maverick owners get rid of their EGR? Nope. But it's an individual decision. It's notable that smog tests are not required in California for vehicles newer than 1975, but when lobbyists tried to raise that to 1981, I understand the state government refused. Also, many of the replacement engines, especially those with fuel injection, are helping to lower pollution from Mavericks so it might be that the net contribution to air pollution from Mavericks and Comets is actually dropping. MD
I was thinking the same thing take ALL of that smog stuff off and throw it away you dont need it. youll be surprised with how little vacuum lines you actually need then you can adjust your carb and it will give you a lot less headaches and end up really reliable
Got it blocked off. Just welded a plate to the ports, and it's so much better. Now just gotta find a reliable vacuum diagram for a 72 without a/c
Only vacuum line I have is going to the distributor advance. Use to have one going to the automatic transmission also before the t5 swap