Kent. I think that I may have to make a house call on this one

 

please confirm that the fuel return line is free flowing, reads like a symptom of that kind of plugging.

 

Blew through it, and it is clear. Made some nice gargling sounds.

PS I have had my nikki deadheaded before. No problems.

 

Sounds like you're no longer hypermiling the car, then, Stu. Where was your mileage before you came back to us?

 

You lost me crit. I made 33 or 34mpg city hypermiling.

That was a few months back.

Sucks cause I was about to hypermile it again, this time on the highway. Figure I would hit up the OGTA meet and head back, check it like that.

 

Did you grab that other carb from Josh's house and try it like I suggested?

 

I am still AT josh's. And now it is OUR's.

 

I think all that hypermiling has pissed off the car's sportscar heart, and it is now exacting it's revenge.

If the bowls are and remain properly full when running, it's not a pump or fuel line problem.

If you're sure it's not feeding gas from the bowls properly (you said even the accel pump feed looked anemic), carb is the only possibility.

From the wild hare department; any chance you've developed an exhaust restriction? If air can't flow out, nothing much flows in either.

Tried a vacuum gauge?

 

Bump. So I got another carb. Has maybe 2000 miles since it was last rebuilt, and pulled off a running car within the past week. Start it up and the same thing happens.


So far:

New fuel filter
Cleared the lines to and from tank
New rebuilt carb
New plugs
Cap and rotor has maybe 1000 miles on it

It has maybe 2500 on the oil change. I am thinking I should change it out now, since that is when I usually change it. Is there anyway to completely drain all the oil, including the cooler? I know it has a thermostat in it, but if the car cant run, it can't warm up.

 

- any cats on the car? (I doubt it )
- so shutter valve is removed, right?
- have you tested the fuel pump volume output?
- maybe you have a bad plug wire or bad coil (could check with timing light)
- double check cap/rotor for damage

 

No cats.
Nothing on the carb but a throttle cable
Negative.
Checked coils, they are good. Might need to get new wires
Double checked, they still look brand new.


I can't think of anything that will cause it to act like this after high RPM. It was fine, then I "blew the carbon out" and now its shitty

Going to do the fuel pump volume test.

 

so, did you ever get this thing figured out?

 

I'm still putting money on exhaust blockage.

 

Nothing in the exhaust TO block. It is all free flow. The only thing that might break off would be the rear muffler. I will shine a light down it and see what I can find.

 

Stu. I hate to say it, but are you sure your getting good compression on all faces of each rotor?

 

Yes, I have checked 10 times, literally.

 

Maybe theres something stuck down in your intake manifold or maybe a gasket got sucked into the way but then I would expect some other symptoms like running rough? Hmmm, take the intake and carb off and see how the gaskets look.

 

Oh.

No pre-silencer that may have had the grid break up internally & pile up in the flow path? Had that happen once on a different car, behaved much like what you have described.

Maybe a rat crawled in there and died?

One other thing you might check, it's low probability but it's easy; loosen your belts and see if the alternator and water pump (& AC if you still have it) turn freely by hand. I once had an alternator bearing sieze so badly on my old Camaro that it stalled the 305 at highway speed. A long shot, but too much mechanical drag could act this way.

 

 

 

Well, I ran out and got some hose, and a bolt with some clamps, and clamped it all up nice and tight, so no more vacuum leaks.












Started the car and still sounds like ****.

 

Well I give up. It is going to Mazda on Monday. A buddy there owes me a favor.

 

Bump!

So the verdict is in, I didn't have to go to mazda. Pulled the plugs again (after fixing the vacuum leak) and they were drenched on the rear rotor. Pull them out and gas slid down the outside of the engine :O

120 miles on her today

 

Wow, glad you finally solved the mystery~ I bet it felt good stretching your (and your car's) legs once again.

 

congrats! ... so the vac. leak caused it to foul a plug?