I started talking about this in another thread but thought I might start a new one to get some more looks and not be a hijacker

<O</OWondering how many have an egr set up with the vacuum amplifier and solenoid and how many without.

Here is a pic of amplifier and solenoid:



<O</O
As these items wear out, I have already repaired the diaphragm in the amplifier, I can only assume they are going to be difficult or impossible to find.
<O</O
<O</O
I would like to keep the EGR functioning with out the amplifier if possible; also the big reservoir seems to be in this loop as well it would be great to get rid of that coffee can!


<O</O
<O</O
My shop manual shows a set up with no amplifier wondering if anyone is running that way and how you have it set up.<O</O

 

At a bare minimum, you should be able to get away with nothing but the EGR valve running to ported vacuum through a 2-port PVS. Most accessories beyond that were added to obtain marginal decreases in emissions. The important piece for driveability is the PVS (EGR shouldn't be active until the engine is at operating temperature).

 

The vacuum amplifier was employed so that the EGR could be controlled by venturi vacuum which, while a more accurate indicator of throttle position, was too weak of a signal to operate the EGR all by itself, hence the "amplifier". I agree with fmc400, you can delete the amplifier and coffee can and just run it off of ported vacuum, most EGRs ran this way, and the difference will be negligible. WOT performance will actually improve if anything.

 

That is exactly what I was hoping, will really clean things up under there.

I re-plumbed it last night with the 2-port PVS leaving everything else in place until I get some test runs in but sounds positive.

Thanks for the input really appreciate it.

Hey fmc400 notice you are in Austin I spent a couple of years there in the early 80's what a great place

Thanks again!

 

Indeed. Probably was a lot smaller back then than it is now though. Sounds like jas88 is nearby too. Small world.

 

Finally got some time this weekend and decided to try an experiment.

Goal is to simplify the vacuum system as much as possible but keep a functioning egr and evap system.

This is the purge valve setup I think this is how it was originally set up so should be okay


I removed the Vacuum amplifier, solenoid, vacuum canister and about 8 vacuum lines.

This is the way I currently have things routed:




One thing I am wondering is if I should put a delay valve before the egr, if egr kicks in immediately off idle wondering if that wil cause a stumble?


I have not driven it yet, hopefully tomorrow!

 

When i got my 78 bronco with 351 goin the egr was bypassed. I checked to make sure it functioned properly and it did. So I ordered the correct vacuum port temp sensor from rock auto and installed it in waterneck. Ran new vac lines. Egr is running off of ported vacuum on carb and only receives vacuum off idle and at operating temperature. Seems to be working fine with no stumble and i left out the delay valve.

 

I have a similar set up. I removed all the excess plumbing and running my EGR valve from the ported vacuum of my Edelbrock carb and T off to the dizzy. My problem has been that the Edelbrock has too much vacuum and my EGR valve begins to open as soon as the PVS valve opens. I haven't figured out how to fix this little problem yet.

 

That is good to know, hopefully mine will be the same.

Thanks!

 

Thanks for the input, hopefully mine wil work out as well.

I wonder if adding a delay valve in the line would help? I had a couple of them in the stuff I pulled off, looks like a sprinkler dripper, don't really know the exact function though do they act as a regulator or just a time delay, maybe someone can chime in.

 

NBC-Steve, forgot to ask did you keep the EVAP system intact also? Assuming you have to pacify our frinds at DMV every two years are you switching carb/intake for the test?

Thanks!!

 

Yes, It's a PITA. I have to swap out the carb and dumb down the timing so I will pass. Fortunately I have a 1 Ton so I am exempt from many of the emission control devices such as the EVAP system and CATS so the process is rather easy. The thing they look for is the EGR valve. I can keep the Edelbrock intake manifold on but I have the OEM intake in storage just in case someone else does my smog and they want to play hardball.

 

Mine is a 1-ton also 9200# GVWR. It was originally a Cali truck so no cats or pump just EGR and EVAP luckily with dual tanks no pressure test just new gas caps every couple of years.

Passing with the manifold is interesting, I may have to make that upgrade, maybe paint it out ford blue. I did replace the 4350 with a Holley 4160 it is a smog replacement unit not for my year but it all looks pretty stock and had a factory 4bbl so not expecting any issues.

I have only smogged mine once but you are right was not that big of a deal, I think the 1-ton increases all of the allowables as well so hopefully it will continue to pass without a probblem.

Thanks for the help and BTW......... I have said it before but worth repeating KILLER TRUCK!

 

I should read signature lines, I see you do have a F350. (Duh...) and a factory 460 so you should pass be pretty easily. Mine was more challenging as the 400 did not come with a 4BBL so that's why I have to swap the original carb back on for the bi-annual smog test. It's a silly state we live in.

Thanks for the complement!

 

check your EGR for a threaded pintel. You can loosen the lock nut and unscrew pintel to increase the vacuum needed to raise the pintel and open the EGR. My Mazdas was doing the same with slight vacuum being applied at idle and causing a dirt idle. I raised the vacuum level and that kept the EGR closed at my slight vacuum idle. Worked great, and I later found that the EGR vacuum amplifier was leaking vacuum to that EGR port. I disassembled it, cleaned it and applied indian shellac to all the gasket mating surfaces and now I have a leak free amp and reset the EGR pintel so it opens right off idle.