Zero compression & weber

[sandshadow]

Hello,

This is my first post, though I've been lurking for a couple of weeks since I bought my tercel. So consider this a bit of an introduction as well as a solicitation for advice.

I've been looking for a Tercel or Corolla All-Trac for a month or so. Early Jan I found an 87 Tercel AWD 5+ speed. It has a nearly perfect body and interior, especially considering the high (235K) mileage. It ran OK, though the seller said it had low compression in one cylinder.

I've pulled the head from a 3AC before - I had an 80 and 82 2WD back when I was a pizza driver. So I wasn't scared to do some head work. I don't want to have to do anything to the block though. Based on the compression I got it for $600.

I've purchased a new compression guage and tested it. 3 cylinders have great compression - 178, 170, and 183 psi. But the number 2 cylinder has zero compression. From what I know, that almost has to be a stuck valve.

Question 1: does anyone out there know of anything besides a stuck valve that could cause zero compression in a cylinder?

I used to have a pickup with a 22R-C, and I put a Weber carb in it when the factroy one went bad. I liked the results a lot, and would like to put one into the Tercel as well.

Since I have to pull the carb as part of the head job, I thought I'd put the Weber in at the same time. Part of me says maybe I shouldn't replace two major components at the same time though. As far as I know, there's nothing wrong with the stock carb.

Question 2: any opinions on whether I should install the Weber as part of the head job?

I've added a poll for question 2. Hope I set it up correctly.

Thanks,
Eric

[GTSSportCoupe]

It could be a blown head gasket too? Either way, it sounds like you'll be pulling the head off anyhow. Pull the head, clean it up, get it resurfaced, check the valves etc., replace it with a new gasket.

I'd put the weber on a the same time if I was you. You can't really go wrong. It gets rid of all the emissions and vacuum lines (except for the ignition advance vacuum). There are a number of us with this carb on their cars on this forum; so if anything goes wrong, we can give you help.

[sandshadow]

Thanks - I think I'll go ahead and install the Weber at the same time.

Checked in at a local parts shop I like and it was well over $500. I found it online for $417.

[GTSSportCoupe]

Thanks - I think I'll go ahead and install the Weber at the same time.

Checked in at a local parts shop I like and it was well over $500. I found it online for $417.

Make sure you get the DGEV variation. It has electric choke which is easier to use than a water or manual one. Also, it faces the right direction. You'll need to get an adapter kit too, and a low profile air filter. I ordered direct from Redline/Weber in the US.

[sandshadow]

I've ordered the carb and kit. It's the 32/36 DGEV with the low profile air filter. $420 incl shipping.

Did you install a fuel pressure regulator as well, or an external fuel pump? Weber suggests it and I remember someone's post saying they were blowing all their seals with the stock fuel pump. If so, what did you go with?

Thanks

[GTSSportCoupe]

I've ordered the carb and kit. It's the 32/36 DGEV with the low profile air filter. $420 incl shipping.

Did you install a fuel pressure regulator as well, or an external fuel pump? Weber suggests it and I remember someone's post saying they were blowing all their seals with the stock fuel pump. If so, what did you go with?

Thanks

I've left the stock fuel pump in my car and have had no issues thus far. That said, maybe I've missed something and should have installed a different fuel pump. Is it possible to install a fuel pressure regulator with the stock fuel pump and not have a fuel return line back to the tank?

[takza]

I THINK the pump is designed to regulate pressure and flow and then dump the rest of the gas back to the tank. Guess you'd need to go with electric.

Have heard of using extra regulators and reducing PSI way down to save gas.

[GTSSportCoupe]

I THINK the pump is designed to regulate pressure and flow and then dump the rest of the gas back to the tank. Guess you'd need to go with electric.

Have heard of using extra regulators and reducing PSI way down to save gas.

Ah, ok. For some reason I didn't think that the tercel had a return line, but maybe it does.

I was wondering if lower pressure would affect fuel economy. If I'm running too much pressure, maybe lowering it a bit would increase my economy. Although I think if a person ran too low a pressure, maybe the fuel would not atomize properly? Or the engine would become fuel starved in some situations and cause lean issues?

[Typrus]

As far as I know, in a carb setup, the fuel pump only dumps fuel into a "bowl" of liquid, where it collects until the sheer effect of the air moving down the carb barrel pulls it out. The venturi effect. You may be surprised how powerful the venturi effect can be... I fly model aircraft on occasion and they have no fuel pumps. The venturi is the sole mover of fuel. No mechanical parts, just a simple high/low pressure situation. You can pull multi-G loops, rolls, etc without going deadstick (engine stall).
So I suppose that as long as you can keep full supply in the float bowl, no stall-outs will occur?
That is to assume I know what I'm talking about....


And yes, there is a return line. If you pull both lines off the pump, the one where there is only a small hole out of the pump is the return.

[takza]

I was wondering if lower pressure would affect fuel economy. If I'm running too much pressure, maybe lowering it a bit would increase my economy. Although I think if a person ran too low a pressure, maybe the fuel would not atomize properly? Or the engine would become fuel starved in some situations and cause lean issues?

Was just reading this recently where someone was setting up a carb and was using 1 PSI...basically dialed it down as low as he could and where he didn't get any starvation....think it was a 4 barrel too.

[sandshadow]

I did a bunch of browsing, searching for info on regulators, etc.

This article was written for Rotary Mazdas but had some good info:
http://www.yawpower.com/fueldel.html

The regulator I liked best is called the "Filter King". It includes a filter and regulator in a single unit (and looks cool).


It would be ~$50 if I were in the UK, but the only place I found in the US that distributes them wants over $100. At that price, I'm better getting a Weber or Holly regulator.

[GTSSportCoupe]

That looks very cool! Looks like it would totally do the job. Let us know which one you end up using.

[takza]

Finding some good prices on things at Jegs...or at least you can get some info and do a web search.

http://www.victoriabritish.com/

...has a regulator for $40 that adjusts from 1/2 to 5 1/2 PSI...you need to ask for a catalogue to see it though. Might be at JCWhitney...

[sandshadow]

Well, it took awhile, but it's finished now.

Here's the before:


The after:


And the cause of the zero compression:


I've got a lot of photos - maybe I'll write up in more detail later. I'd like to compare some of the things I did with the Weber to how other folks have dealt with them.

[ARCHINSTL]

XLNT photos!
Very sanitary installation - plus ditto engine bay.
Your writeup would be a plus to the genre.
I take it you do not have to worry about even lip service to emissions testing?
Tom M.