According to Carl:

http://www.ten15.net/Maz.tutorials/

 

That is nice! Clean!

 

So are we to assume that you've figured out your poor idle issue, and if so, would you share what was it with the rest of us minions? Can't say I'v seen a nicer detailed carb in a very long time.

 

Was it easy? also, why do you need to install that lawnmower belt? The stock belt only ran the air pump, and thats all the belt runs, so why cant you just remove the belt? There's still the other belt to run the alternator and fan.

 

The stock belt ran the air pump, around the water pump and back to the eshaft. if you remove the belt and leave it, you will only have 10 oclock to 12 oclock on the water pump pully touched by the belt that goes to the alternator, making the belt slip in high RPMs. Thats bad. haha.

 

Oh and nice job Ray! I cant seem to find your breather tube though.

 

Trochoid, no I never really did "figure out" the idle high idle problem, instead I used the scientific method of trial and error. I found that when I loosened the phillips screw on the hot start assist and adjusted it out the idle dropped.



So now I've got a nice steady 750 rpm idle and it runs well, especially when those secondaries kick in, but I'm still not completely happy with the throttle progression, I'm still working on that.

I went with the dual pulley set up instead of the yoohoo belt, it just plain looks cooler. Also it works really smoothly and probably doesn't stress the e shaft bearing like the yoohoo belt might do. But don't tell Doc I used two used pulleys that weren't by the same manufacturer, he said you need to get two new ones with the same manufacturer or they won't work.



Stu here's a better picture of the pipe vent set up:



It's not really a lot of work but I spent lots of timing cleaning, fussing and trying to figure out what I was doing than I needed to. I like the hose layout, a bit nicer than Carl's, I'm sure he wouldn't mind me saying. It took a little playing around so that's why I posted the pics in case someone wants to use the layout.

Oh and here's a picture of the stock Nikki back in:

 

I a few years ago installed this "yohoo" belt and on a drive back from Oregon sheared the water pump pully clean off the water pump. I had to call a friend and have him bring me my tools and a spare water pump 2 hours or so away from home. Needless to say I would not reccomend the "yoohoo screw you" belt. My 2 cents

 

Just an update, today I gassed up after 358 miles, it took the whole 15 gallons. Looks like I'm back in the saddle.

Today's pics:

 

Looks nice ray. Wow, I thought you were never going to take that out knowing you...lol. When its time for me to take mine out, I'll pm you, Cause that rats nest removal looks great.

 

Lookin' good, though I've got mine done with a PCV valve instead - less tubes to worry about.

Jon

 

The PCV valve sounds like a good idea Jon, how do you do it? Got pictures? What does "PCV" stand for anyway?

Thanks!

 

Let me get a pic right quick...

 

PCV valve from a 90 dodge caravan 3.0l

 

PCV = Positive Crankcase Ventilation valve

 

Thanks Stu, I'm still going to have to do a little research to figure out what you've done there, but basically it eliminates the vacuum line to the intake manifold, right?

 

No, I have mine from the top nipple to a pcv valve, to a vacuum nipple on the mani, with the bottom bung from the block to a breather hose.

 

This is what I used on mine:

https://www.rx7club.com/1st-gen-archive-71/fuel-intake-rats-nest-removal-79-rx-7-pictoral-457961/

Hope this helps!

 

Just what I needed, something else to do. That link is great, I'll be giving it a try.

Thanks Stu!

 

No prob man, I love the clean engine bay. Mine is a mess!

PS/Edit: I had a spare set for everything needed for the rats nest removal, but no one wanted it (it was even free!) so I ended up throwing it away...

 

I found some helpful threads on PCV valves and crankcase venting:

https://www.rx7club.com/showthread.p...s+nest+removal

https://www.rx7club.com/1st-generation-specific-1979-1985-18/ive-got-lung-mustard-491461/

https://www.rx7club.com/showthread.p...s+nest+removal

The last thread has these really clear but unattributed diagrams in it that would be a nice addition to the rat's nest removal tutorial:





So all in all, I think my vent set-up, ala Carl and Pratch, is fine and it keeps with the spirit of a stock car, no walmart or autozone "aftermarket" tinsel.



However, if putting in the PCV valve instead of the stock purge valve would clean things up a bit more, I might do it. Could someone take the upper line diagram (the one without AC) and show me how a PCV valve would be installed to replace the stock purge valve?

I have some ideas based on the PCV threads but descriptions for how to get vacuum to the PCV valve are a bit vague and contradictory in some cases, it seems to me. What would be the best arrangement for the PCV plumbing?

Thanks
Ray

 

ray, awesome thread!!!!! did you use an fc spider valve?? how does the engine run since you cleaned up the engine bay?

 

The engine is FINALLY running great.

You know what the last little problem was? Spark plugs.

I've been in the habit of just cleaning up my plugs on the wire wheel and rotating between the 4 or 5 sets that I have lying around. But after 5 years of this questionable habit, I think it's finally catching up with me. I put in a new set, Denso's this time because they were available at autozone and a little less expensive - I couldn't find the NKGs on short notice.

This really helped smooth the idle right down at 750 rpms and the throttle progression is much better. I'll see if I can get wife Cathy to help produce a movie on the running engine and post it a bit later.

No on the FC spider valve, I don't allow 2nd generation parts in my car. And Dave since this has mainly been an educational experience for me, could you tell me just what a "spider valve" is and why they named it that?

Thanks for the compliments, can anybody tell me how to hook that PVC valve?

 

The PCV valve has a one way spring loaded air valve in it. It is supposed to let air into the manifold, and not let it out. This helps vent the engine even with the strong reversion waves at low RPM.

The PCV valve must connect to both primary manifold runners. At least that's how the stock ones are set up from the factory. It's basically a large threaded cavity with two small holes; each leading into a primary runner.

I've found the Fram (?)333 to work well (can't remember the letters before the numbers). One side is 5/16" and the other side is a 1/4NPT threaded fitting that is roughly the same size as 3/8" so you can use rubber hose on both sides. The threaded end faces AWAY from the manifold. If in doubt, blow a little compressed air through it and see which direction has the least restriction. That's the direction the vented air flows into the manifold.

Perhaps you can find a better PCV valve with more appropriate fittings. We just grabbed the 333 because we needed one for the SC install and it looked like it matched the Edelbrock's PCV nipple in size (too bad the 333's flow direction was reversed from what I thought it was).

 

Which Denso plug did you go with? The NGK's are getting harder to find around here so I might give these a try.