EGR, Smog pump removal 91 Pros and Cons

[74TLC]

Hi Folks, Ive got a 91 FJ80 that I acquired recently thats a nice starter truck with a few miles, gray and grey with only a faded roof and a couple of small dents. It has a brake booster problem(replaced a yr ago) and then found a radiator leak. So I took out the radiator to try to find leak and hopefully fix but shop said the tank was leaking and would be hard to fix and didnt bother to show me where the leak was so I guess its time to replace it too. Anyway while taking out the radiator I had to dismantle a few things and finding a few other potential problems with idlers and such, a nasty looking "center" water pump hose(how does this thing come out) that looks to be the original piece at 250k. I removed the airpump for some reason and a couple of hoses then the rt side blower motor all the vacuum gadgets behind the blower, then I decided to take off the egr to see how nasty it was (it was). Then wondering "does all this junk have to be on there for this thing to run properly" I live in AL which has no emissions checks so what all can be removed safely? Would like to remove the air fittings in the head and all the related tubing also but it will be hard to get to w/o removing the intake. Any ideas would be appreciated.

 

[alkaline747trio]

http://www.ih8mud.com/tech/3FE-Desmog_Guide.pdf

Do it, and never look back!

 

[Pin_Head]

My opinion is that it is not worth the effort to remove all that stuff and you may limit your resale potential to areas where they don't check.

 

[alkaline747trio]

Pin, have you ever run an 80/62 with a full desmog? I would say a desmog with the few other tweaks that don't cost anything puts the 3FE right on the 1FZFE's heels.

 

[Pin_Head]

Not "full desmoged", because I live in the Peoples Republic of California.

My experience is with engines on which the smog control is broken or inoperative for a varity of reasons. I could not detect any difference in performance or mileage with the EGR blocked off or operating properly. I have a similar experience w and w/o the air pump: no detectable difference.

I am sure that you wouldn't be able to sell a desmoged 80/62 in the PRC.

 

[RavenTai]

The 3-FE in my 62 is de-smoged, the air pipes come out without removing the intake, requires a bit of finger contortion, also the air lines were badly corroded and did not survive the extraction in one piece.

I deleted the smog pump and the EGR, I did not notice a change in power or mileage but I did it shortly after acquiring it so not much history, it is much easier to work on the drivers side of engine and I did not have to fix a lot of missing broken & broken crap on my 3FE by simply deleting it.

I would not say that it has the power of my 1FZ even desmoged.

Couple corrections for the de-smog guide, he has you cap all of those vacuum lines at the cluster running to the fender, the two lines for the fuel pressure regulator should not be plugged, this kills the intake manifold pressure sense line to the FPR, that would make it run rich, you should instead make a short jumper vacuum hose from one hard line to the other, that may be part of the power you guys are reporting but will also hurt mileage, the richening effect would be greatest at idle and least at WOT. Opposite of how we would want it. I may have a few ponies hiding in the cats, the cats are aftermarket and I do not know how well they flow but it would have cost money to have pipe put in their place, they are welded in so no easy way to gut them and reinstall.

Also the NPT brass plug for the EGR did not work well for me at all. The threads are not even close and after a few drives it loosened up, I retightened it a few times but it would loosen every time, so I filed down some washers to fit to two steps in the original exhaust nipple then ran a bolt through the washers to keep them in place and doped the whole thing up with exhaust sealant, has worked great. If you have access to a TIG welder that would be even better, I think the nipple is stainless.

My 62 is a near beater, it is a rust belt truck a local cruiser shop used it as a parts vehicle for a few years, ( I got it real cheap ) in this case it made sense to go this route, I would keep it stock on any 3FE’d vehicle that you consider valuable. The resale angle is accurate if that is important to you.

 

[jonheld]

I run a York in place of the OEM smog pump on my 91. Its removal changed nothing discernable and I still pass NJ state emissions.

 

[alkaline747trio]

Raven, the cats make the biggest difference, and removing the EGR allows you to advance the timing further (in my experience).

Richening the MAF sensor also helped out my power situation.

I appreciate you pointing out the FPR, I had wondered about that and I believe I will rig up something to make that work properly, unless it is still running richer at WOT than normal?

 

[RavenTai]

Well the fuel pressure is suppose to be a set psi above intake manifold pressure so that there is a consistent differential pressure across the injector, that way the mass of fuel delivered for a certain injector open time is consistent regardless of manifold pressure.

With the line capped the fuel pressure is referenced to ambient and does not track along with intake manifold pressure, at idle when the intake pressure is lowest is where it would be the most off in the rich direction, at WOT the intake manifold is closer to ambient and it will be at its closet to accurate because intake manifold and ambient are at their closest.

It would be best to have accurate fuel pressure and therefore consistent fuel metering and make your tweaks elsewhere such as the air flow meter as you said.

it is simple to fix just route a 6" or so vacuum line from one of the hard lines to the other so that the pressure signal continues on, there was a VSV on the fender that opened the FPR to ambient for starting enrichment, that is why the two vacuum hoses went out to the fender, obviously it was not needed as both yours and mine start fine without it.

 

[alkaline747trio]

Can you snap a pic showing the route for the FPR after everything else is gone? All my vac hoses got snagged out.

 

[RavenTai]

pic

 

[alkaline747trio]

Thanks raven...

 

[davisdrafting]

pic

Thanks for the help on the FPR.

Tip to you, don’t use those rubber vacuum caps they will crack and leak.
I found the vinyl ones at the hardware store work better. The kind you find
on the end of a wire rack / shelf. They should be in the hardware section.

 

[cruiser88]

Thanks for the help on the FPR.

Tip to you, don’t use those rubber vacuum caps they will crack and leak.
I found the vinyl ones at the hardware store work better. The kind you find
on the end of a wire rack / shelf. They should be in the hardware section.

yes go with the vinyl ones.im finding mine in the driveway

 

[RavenTai]

Thanks for the help on the FPR.

Tip to you, don’t use those rubber vacuum caps they will crack and leak.
I found the vinyl ones at the hardware store work better. The kind you find
on the end of a wire rack / shelf. They should be in the hardware section.

Yep, I had not noticed until I had the pic on screen bigger than life that those are cracking already, they are around a year old maybe a little longer, way to short of a life span, I'll look for some vinyl ones, If I cannot find I'll replace them with vac line plugged with rivets.

 

[Spicer '92]

I could use a hint from you guys. Yesterday i removed a vaccum line from my EGR and the male metal part on top of the EGR was rusty, brittle, and some broke off. Is my EGR valve likely bad? What would a new one cost $$$? Also what would a new VSV cost $$? I have read on here that a guy that replaced these two parts had a much stronger feel to his cruiser. I have a couple questions regarding a de-smog (yes I read the other posts but not all of my questions were answered . . . or at least I could not find them) How much is the Dayco #22528 belt $? Im sure I could pick up the other 1/8" plugs and exhaust plug for $15.
-Also most that have desmogged thier 3fe's mention taking out thier air injection manifold. Is this necessary, or could I just plug it where the hose connects it because I might want to resmog someday. Is this dumb or could it work. I guess if the check valves are bad and I don't have pressure going into this manifold I could have a lot of exhaust heat coming into this manifold and I don't want that. Sorry if any of this has been covered. Im going home for break next week so i'll have lots of tools at my disposal so im gonna get a lot done. Possibly a 3fe cold air intake too . Thanks
Evan

 

[Spicer '92]

P.S. I go to KU, #1 seed in the tournament . . . GO HAWKS!!! Anyone wanna make some bets?

 

[alkaline747trio]

EGR is probably worn and sticky, probably functional but not as per factory specs. Get the FSM and follow its directions on testing the EGR. No idea on the cost of the new pieces as I would have just thrown them out if they were broken anyways. The dayco belt is cheap, less than $8 bucks at Advance. 1/8th hose will be tough to find, so buy plenty when you get it (1/8th fuel hose works too, just a little larger OD and stiffer). Hose and plugs are cheap. I just bought the 'HELP!' brand cap for the AI rail and the nipple on the air cleaner, works fine. Don't waste your time on a cold air intake unless you plan to NEVER see water, dirt, mud, dust, etc. as the stock intake is large and well designed. A snorkel will help also, as it will bring in colder, fresher air.

 

[arizonae]

I just completed my de-smog of my 91 fj80. On the exhaust manifold I kept the Union and removed one of the nuts from the EGR pipe. I used a half inch knock out from and electrical box and tightened it down. I considered using a quarter, but never made it happen. As you can see I've removed the smog pump and made my own egr block off plate. Everything seems to be working properly, but I haven't done any serious driving yet.

 

[Spicer '92]

Creative . . . Looks good. Let us know your results. I plan on my desmogging this weekend.