Yup, it's doing that much more than it normally does. Again, leak, but I can't find it!

And I thought I'd mention that I checked the spark plugs, they're closer to black than brown, but they're dry.

And I thought I might have stupidly put the dist cap 180 degrees out, but nope, it only fits on one way and I looked at old pics of my engine bay and it's the same.

Jon

Wow... in attempting to describe a vacuum leak to a friend on MSN, I actually found a pretty good explanation and thought I'd post.

Vipernicus:
Here's the best way to explain it.

You buy a slush puppie (or "Sloche" if you're on the quebec side... they've got bigger straws anyway)

And you're happily drinking away. Then, somehow, a small crack forms in the side of your straw, about halfway up.

What happens to your attempts to drink the slushie?

Kat:
pressure drops and no slushie

Vipernicus:
(the drink is really inconsequential... I just thought slushies would be harder to drink with that problem)

Exactly since air from the crack is easier to suck in than the slushie you get no slushie.

My car has this problem, but instead of drinking slushie from a cup, it's trying to drink a mix of air/gas from the carburetor.

So it gets too much air, with not enough gas mixed in, and won't run.

Found something interesting today on the brand new engine with the old nikki.

When I first started up the engine, it had a high pitched squeel, I thought it might have been the thrust bearing, which I replaced.

I took a hose and listened to all of the areas around the engine and the sound was coming from the intake manifold toward the front. I found a loose intake manifold bolt, tightened it up and the engine ran much smoother.

Go back and check that all of the intake bolts/nuts are tight. Spray the manifold/engine interface with carb cleaner and see if that helps.

RXDad

For arguements sake, let's say there isn't a vacum leak, even though it has the symptons of one. If your plugs are leaning towards black, it sounds like it isn't running lean, substantiating maybe no vacum leak.

If it ISN'T that, then what could it be? I'm grasping at straws trying to give you ideas here Jon.

How about leading ignitor failure? Or leading and trailing reversed?
Any way you can get somebody to get a timing light on it while you run it?
Any chance you've blocked off something you shouldn't?
I remember you had trouble locating the bottom manifold bolts - any chance you forgot them?
What about those plugs you were desperately trying to get out thinking they were the lower manifold bolts? And you did torque the manifold bolts in the correct pattern, and to the correct torque?
I'm really stretching it here, but any way the exhaust is blocked? That will do exactly what you've been describing.
Not sure, but I think if the diaphram in the brake booster goes, it creates a huge vacum leak. Can't remember if you tried blocking it right off or not.

Just some ideas, since it honestly seems like you covered the bases for vacum leaks. Also, a vacum leak of that magnitude should make it run very lean, and the plugs should be almost burnt, although I supposed pumping the accelerator circuit may may it really rich - I dunno.

Rob

Found It!
 

Now if I could only *fix* the problem I found.

When I originally took the manifold off to do the installation of the freeze plugs, the original gasket flaked off in pieces. I thought that I had gotten all the bits off, but as it turned out, it broke PERFECTLY along the line between the front/rear housings and the rotor housings.

Essentially, all the way around the secondaries there was 1/16" of gasket, and around the primaries it was down to the metal.

So no matter what I did or how much gasket compound I used, there was still a huge gap at the primaries that I couldn't close.

So now I have to get the rest of the old gasket off, but it has hardened, or rather CURED so solidly, that I actually had sanded it flat and thought it was metal, until I managed to break a piece off.

Here's some pics of what almost 3 hours of scraping accomplished. You can see the small amount of gasket material on the outermost sides that managed to get removed.

Anyone know of a solvent or something that could get this stuff off? It's 22yrs old and being as stubborn as can be.

Jon

Ahh, you must feel good! Nothing like finding the issue when something fights you so hard. I've been going through the same sort of thing with our boat all weekend, and I'm about as fed up as you must be!

Best thing I've ever found is Permatex Gasket Remover. I got it at NAPA, but maybe Crappy Tire has it too. I know you just got a lot of powder coat, so whatever you do, watch where you spray the stuff. In my limited experience with it so far, it east or stains just about everything.

i normally use a razor blade and some wd40, but it sounds like you are beyond that! ;)

Jon, I just looked at your most recent pic. Once you soak it in the gasket remover, I would use a drill with a wire brush wheel to try to get the old gasket off. With a scraper against the aluminum, its just too darn easy to wear into it, or chip it. You're going have to scrape so hard, I think its a possiblilty.

great idea! Im going to have to remember that.

The rotor housings don't have any gasket, it's the cast iron end plates, so I'm not too worried about marring them with the putty knife I've been using.

But I'm *definitely* going to pick up some of this gasket remover stuff you mentioned.

Found some info on it. Sounds like EXACTLY what I need.

http://www.permatex.com/products/aut...et_Remover.htm

Hopefully Canadian Tire has it. I work Mon-Thurs from noon-10pm so I'll only have a small amount of time to work on it (an hour before work every day).

Hopefully this will fix me up so I can leave for Sterling's place Friday :D

It should be the last setback... other than the possibly dead efan of course.

Jon

Edit: I knew it couldn't be a carb problem.. I'm too good with them for that ;)

once you think you've got every last bit off, take a peice of steel stock the length of your manifold and make sure everything is square. Just like when checking the end and intermediate plates for wear. When i changed my intake gasket i was amazed at how much gasket was still there, yet looked just like the iron.

And amazingly enough I have a length of steel stock left over from when I made my e-fan mounting brackets!

Thanks Gavin

Jon

Times like these I thank god for giving me an air compressor. Nothing eats old gaskets off better than a grinder :) Dont you just hate when the problem ends up being that ONE little thing that you just happened not to notice.. :)

not to hijack a thread here or anything but what is the correct pattern for bolting up the manifold?, i just replaced the o-rings in mine and now im having similar problems.

I got some of that gasket remover stuff today. It *does* eat through the gasket, but it does so in thin layers.

I soaked the gasket, left it 10min (as per instructions) and came back with my putty knife. Out of the 1/16" of gasket, I probably managed to remove 1/32" on the three rounds of soaking/peeling I did.

But one thing I will say, now that I've wirebrushed the area, the metal really shines through as metal. I think that it'll work just fine once I get the whole thing down to just *metal* all the way accross.

I'll snap some pics later.

Jon

Glad you got it solved. I also use combinations of WD-40, scrapers, razor blades, wire wheel. Whatever works on that particular gasket. Keep chipping away, youll get it. :beerchug:

What'd I miss? :scratch:

Everything looked fine in the photos, save one big no-no...

-Using bolts as plugs.

Air leaks around the threads in bolts that are shoved into the hoses, and being that those hoses are over 20 years old, they don't likely have the flexibility to conform to the threads' surface for a good seal.

Multiply the "fairly good chance of a tiny vacuum leak" times the 6 or 8 hoses you have hangin' off the thing, and well you have a high probability of a rather small, collective leak.

...Look at the small idle air bleed and emulsion tube air bleed orifices, and you can see how this type of thing could wreak all kinds o' badness.

I would start there.

...& leave yer damn floats alone! :P

Sterling, the only thing you missed were the later posts where I found the problem....

'cause you're right, everything in the first post is fine. It turned out to be a leak where the manifold mates to the engine, due to crappy old gasket material left over from when I took the intake off to install freeze plugs!

And the bolts are clamped down.... until next weekend :p:

Jon

She LIVES!
 

I finally got all that old gasket material off.

It took 3 days, lots of gasket remover and a round wirebrush on a drill, but I got it down to the metal. Bolted the intake up with just the new gasket, no sealant, and boom. Runs smooth as silk, 900rpm idle, all vacuum things re-hooked up.

And the e-fan I was worried about actually does work. In fact it works *too* well. I had wired it to a constant 12v source, but as it turns out that's too much. It keeps running when the car's off (as long as the rad is hot) and drains the battery. Well, trochoid warned me of that, so I'll just wire it to a switched ignition source and it'll be good.

Everything's good to go, I'll post pics early next week when I make a thread about the new intake/carb I'm getting installed this weekend :)

Thanks to everyone who helped. As Rx7Carl put it in a PM he sent me "This problem SCREAMS vacuum leak". And what a leak it was!

Jon

Glad it worked out finally Jon. Thought the wire brush in the drill would work. Kinda makes it all worthwhile now eh?

Oh yeah.

82 flawless kilometres later, I'm very happy with my work. It's nice to know that after tearing everything out of the engine bay except the block itself, replacing a dozen or so parts, and reassembling everything that I didn't have any other major problems.

All the hose clamps were on tight enough, no leaks of any sort (coolant or oil)

All my soldered connections were done well and heatshrinked (no drain on the battery or electrical shorts/glitches). My FC Fuse box went in easy as pie and is definitely more reliable than the old fusible links. The trimmed wire harness has no adverse effects and the old useless connectors are finally gone.

The new coolant resivoir, rad, and rad cap work as expected. I didn't have to burp any air pockets out of the system. I just filled it very slowly to let most of the air escape, then filled the resivoir and kept an eye on it as the system did the rest of the work, bleeding itself out and replenishing from the resivoir. Nice to have that working again.

The e-fan actually works.... in fact it works too well. I'll have to switch it over to an ignition switched positive source instead of a constant one, because it runs so long after the car turns off it starts to drain the battery.

Everything came together really well. Just the one vacuum leak, and the bent oil cooler hose as major setbacks that had to be taken care of.

Now I make my trip to NY for my intake manifold and carb, and when I get my new pulleys I'm going to time it and install the FC coil and TT box.

Things get better by the day.

Jon

Its makes you feel really especially victorious when something gives you a hard time like that and in the end turns out so well. Good stuff!

No leaks or complications shows you did the job right!