Just curious about this one. I am in the process of putting a lower mileage H.O. 5.0 in my 1995 F150. The upper intake took several days to clean because of carbon and oil deposits. I was just curious what effect plugging the EGR tube at the lower intake would have on the truck. Is it absolutely necessary that flow be maintained to the valve?

Thanks,
Keith


2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

The only ones I can think of is it won't pass the emmition tests.

 

We don't have those in Florida right now I just had heard conflicting info about it before. Something along the lines of part-throttle detonation when no egr flow was maintained. Thanks for the reply though.

2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

Your engine will run just a bit hotter, make a bit more power but may need to have the timing retarded a little if it pings with the EGR blocked.

 

Cool! Thanks


2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

> The upper intake took several days to clean because of carbon and >oil deposits.

Keep in mind much of that is from the PCV.

My EGR valve has been stuck closed for quite some time now. One theoretical adverse effect is this: 02 that would normally be displaced by recirculating exhaust gases is not, so more 02 is present. As such, the ECM compensates by adding that much more fuel, thus potentially reducing mileage.

 

[updated:LAST EDITED ON 01-10-03 AT 08:09 PM (EST)]That makes sense. I still haven't decided what to do yet. I haven't been able to find a plug for the lower intake to block it.

2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

how can one retard the timming on a 1991 f-150 v8 with little or no experience. is this something you gotta take you ride in for or could i do it alone at home and what tools do i need
thank you.

 

I blocked my EGR off 2 years ago with no apparant side affests. Timing is set at 10 degrees BTDC. If you have a good timing light you can do it yourself. You need to know that the timing "spout" needs to be unplugged before you start the engine. This "spout" is up neer the the firewall on the drivers side. It is a 2 wire pigtail (pink wires)
with a plugin on the end. The plug is removable. With a warmed up engine remove this plug and start the engine and time it to 10 degrees before top dead center. Shut off the engine and replace the plug. This will now give you your proper timing. I hope I didn't miss anything, but if I did I am sure some one will pick up on it and correct the mistake.

 

I know what you are talking about on the crud buildup. I really do think that most of the buildup is from the EGR vs the PCV. When I took my upper plenum off the first four runners closest to the EGR had a good 1/4 of carbon/crud buildup that even a hot high pressure washer wouldn't knock off. The back of the plenum closest to the PCV inlet was really relatively clean. I wonder if the PCV stuff being introduced is somewhat solvent of itself and kinda keeps the goo moving thru the system whereas the EGR gasses introduced has very little solvent ability so it sticks and builds up. A 1/4" of buildup in those front runners HAS to be causing restriction and fuel/air problems in the front cylinders. My thinking is that the front cylinders become somewhat starved of air causing a fuel rich condition there. The computer probably reduces injector duration overall so the end effect is the front four cylinders are probably still running slightly rich and the rear four end up lean. I look at this as a system that works quite well when the engine is new/clean but over time degrades the overall performance of the engine including emissions. I've thought about plumbing the EGR system so it picks up it's exhaust gasses AFTER the cat thinking that maybe the stuff here would be lower in whatever it is that causes the buildup in the plenum. Dunno, just a wild idea.

Randy

 

A question for the people who have blocked the EGR flow. Would it be ok to block it at the lower intake where the tube runs out to the EGR Valve? The problem is, the lower intake is already on so blocking it at the head is not really an option now I had thought about just putting a brass, threaded plug in where the tube screws into. But if I remember correctly, the little box on the bottom of the lower intake, directly underneath where the tube screws in, is not really sealed all that well and would allow some exhaust gases to flow into the crankcase


2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

I made a plate to fit between the EGR and the manifold out of stainless steel shim stock but tin plate will work as well. I used the gasket as a template but instead of punching holes I cut across from the side and up from the bottom so I could just slide the plate in just by loosening the bolts off instead of removing them if I needed to have emission tests done. I also made the plate with a tab at the top to help install or remove the plate. On another note, on a mid 80s Nissan truck I had I just undid the nut on the tube and put a coin in to block the flow and did up the nut again. This also worked just fine, cheap and easy too.

 

Thanks! I made a plate to block the EGR and one to block the throttle body to keep it from leaking when I had it soaking in carburetor cleaner for two days. Never thought of using the same plate with the EGR bolted over top of it Thanks again!

2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

so no one has lost milage from blocking off the EGR, wont it throw a code and make the check engine light come on?
1992 F250 r/c l/b 4X4 351 ZF5spd 33" BFG Allterrains clarion CD MTX 6500D amp pushin 2 12" 6000 series subs

 

When you block the EGR off only the exhaust cannot get through to the intake manifold. Every thing else functions normaly. My Egr has a sender on top of it to tell if it is open or not and it shows open when it is supposed to be, the computor thinks all is well and therefor no codes or check lights.