Purs like a kitten...

[FastWoman]

... with a bad attitude!

I just wanted to let y'all know I got my engine back together. It's all cleaned up, checked part by part, refurbished, refreshed, painted pretty, reassembled, double checked, triple checked, etc.

It started on the first try, but it ran much like it did before -- exhaust blowing hard and puffing with frequent misses. Engine vacuum a bit lower than before I started -- about 11 in Hg. I had occasional hesitation upon revving, with occasional light backfiring. I had resolved at that point, having gone through the whole system, to make my final adjustments at the AFM... which is what I did.

I first gave the vane a gentle push towards the open/enrichen direction. Engine speed and vacuum picked up A LOT. I dropped spring tension by two teeth and repeated. Higher vacuum this time, but the engine still picked up when I pushed the vane open. I adjusted by another two teeth and repeated... and repeated... and repeated...

TWELVE teeth from where I began, I had a normal engine vacuum (19 in Hg), the engine was running very smoothly, and the exhaust was no longer blowing hard and missing. It sounded like a very content kitten with an attitude.

The weird thing is that the AFM appeared to have had the factory caulk blobs on the set screws. I had assumed it had been unmolested. On the other hand, I knew it had been opened, most likely by the PO. He used clear silicone caulk everywhere on the car and had the same caulk sealing the cover. The silicone caulk on the set screws appeared to be a whitish caulk, so I'm guessing it wasn't his. Did the factory use silicone caulk/sealant/adhesive to blob against the set screws, or was that the handy work of a mechanic along the way?

Anyway, the spring was wound up pretty tight. It definitely felt a lot lighter when I was finished. A gentle push is all that is needed to open the vane now.

The test drive is tomorrow. (Caulk is curing tonight.) I'll take pictures for y'all to show off the engine. It came out quite well, I think. Only the top is painted. Cylinder head and block are as they were. I painted the intake manifold to resemble a '75 intake -- by blacking out the webbing. I think it's much more attractive that way. I have a bit of touch-up painting to do, as engine assembly is frought with nick, scratch, and bump hazards.

Anyway, knocking on wood, I think I'm in the clear now. Thanks for helping me along on this project! I don't think I could have gotten to this point without the moral support and technical advice of my fellow Z enthusiasts.

Peace,

Sarah

[Zedyone_kenobi]

Come on, I hate waiting.. need pics!

[FastWoman]

It's dark!

[Z train]

Fastchick!!!!I was wondering what happened to you.Keep yer eyes out for a spare AFM.Keeping in mind there were FOUR for your year.

[FastWoman]

I guess this project took longer than I expected. I took my time and did it right.

Yeah, I've been looking for a spare AFM. It's actually the last piece of the EFI system that I don't have a duplicate of -- well, that and the intake boots. (I used my spares in the rebuild.)

BTW, special thanks to you, Ztrain! You hung with me through thick and thin. Much appreciated!

[Z train]

I guess this project took longer than I expected. I took my time and did it right.

Yeah, I've been looking for a spare AFM. It's actually the last piece of the EFI system that I don't have a duplicate of -- well, that and the intake boots. (I used my spares in the rebuild.)

BTW, special thanks to you, Ztrain! You hung with me through thick and thin. Much appreciated!

No worries!BTW-the boots SHOULD be still available at the dealer.If not you can use later ones and just plug up the holes where the extra piping attached.

[cozye]

MSA has the boots, I just replaced mine.

[FastWoman]

First test drive: LOTS more power, but some missing at WOT. I think I might be running a bit rich, although I don't see any black smoke or anything. I'll be trying the rough calibration (using coke cans) described on the Atlantic Z site and then will be balancing out the idle with the idle mix screw. With that starting point, I'll take a very long test drive, so that I can compute the mileage and read the plugs.

[Z train]

More power=more gooder.But for some reason,i don't think you're out of the "woods" yet.

[FastWoman]

Well, second test drive tonight. I backed the AFM main spring to 8 teeth richer than where it was originally set, and I advanced the idle mix screw quite a lot to 6 full turns CCW from closed. The idle mix screw didn't seem to do much of anything. Clogged port? (To be tested.) I lost 1 in Hg -- now at 18. However, I'm a bit more comfortable overall. I'm going to focus on mileage and plug appearance. I have a fresh plug in #1 and will read it at the end of the test drive. I'll know very fast if I'm running rich.

Just a hunch: Perhaps the new injectors don't flow as fast as the OEM ones? Perhaps I need higher fuel pressure to compensate, rather than an easier AFM spring?

Wish me luck. :-)

[Z train]

You're starting to get into the realm of"questions that can't be answered on the internet".But as far as reading the plugs go,you need to find a deserted road make a WOT pass thru a couple of gears and then shut it off-do not let it idle!Pull over and read the plug right there.

[FastWoman]

I'll try that, but I think I'm not to that point yet. I'm definitely nowhere near rich. I took an easy, 45mph drive down the Colonial Parkway for a total distance of 36 mi and consumed EXACTLY 1.003 gal of gas (topped off to the brim). If I remember my math correctly, that would be about 36 mpg.

I think reading the spark plug would almost be a formality at this point. I'll do that tomorrow when the engine is cool and the sun is out. I'm guessing white and chalky. Wha'd'ya bet?

So maybe the richer setting I had earlier was the more correct setting. The only problem is that with the spring tension so low, the AFM meter would peg out before the peak of the power band, and then I'd be running lean at WOT.

I'm guessing there's something amiss with my fuel pressure and/or my (Sorensen) injector flow rate. I'll see if I can scrounge up a more accurate pressure gauge.

Maybe the solution is to go with the flow and to get that adjustable fuel pressure regulator to do my mix adjustments? The car took off like a bat out of hell with yesterday's adjustment.