Power issue - I'm stumped

[Sinistar556]

So I've spent the last two months getting my 73' Super just the way I want it and helping it rcover from an engine fire. Before the engine fire, it ran beautifully with power to spare. I had to replace the spark plug wires and air cleaner, along with some other wires, and now it has a different problem.

Symptoms: Starts great, choke works fine, idles fine, even revs while sitting fine. Put it into gear and it goes fine for about 100 feet, then it seems like its either dropped to half power or is missing alltogether on one cylinder. Barely gets moving from a dead stop without stalling and the same happens when I shift up.

Attempts to Fix: All of these were done after finding the issue. Checked and did valve adjustment to .006 as described in manual. Swapped between a few different distributors and caps I had around. Checked, rechecked, rechecked, adjusted, etc timing. Air/Fuel adjustment unsuccessful. All wires seem to be doing what their supposed to. Regapped and cleaned, then replaced spark plugs.

No change.

I'm in over $200 on this issue just in trial parts. If anyone can shed any light on my problem, I'll be sitting at this computer doing work all day and will drop everything to try your suggestions.

Thanks,

Tom
No longer stuck on the side of the road - if you remember that post.

[TexasAircooledParts]

Did you do a compression Test?
http://www.vw-resource.com/tune-up.html#compression

Did you check the valves when the engine was cold?

[drscope]

Sounds like it may be starving for fuel as the demand increases.

Check your pump output and also the flow to the pump.

Or the float in the carb may be way too high.
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Mother Nature is a Mean Evil Bitch!

[miller0358]

Maybe a vacuum leak? Jeff

[rgm440]

I don't know how bad the fire was but the fuel pump diafram or carb it self may have got hot enough to received damage.
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It's fun to be Crazy -- But damn it's expensive -- Besides - the devil made me do it -- make it a double this time

[Sinistar556]

Update: Took the carb off and apart. Everything seems to be in order there. No breaks or leaks in the diaphragm, float is still floating, and all jets and opening are open and clean as well as all gaskets in place.

Going to go back and check my valve adjustment now. Keep the suggestions coming, its only 2 in the afternoon here.

[Sinistar556]

Valve adjustment revealed nothing wrong, maybe just one valve that was a hair too tight.

Seems like the vaccuum system is working properly and the fuel pump because there was gas coming throug even when I hand cranked the motor to do the valve check. Don't have the tools for a compression test, but can get them if things keep progressing at the same rate.

Still stumped. Gonna put it all back together and go for a ride and see.

[miller0358]

Check the jet in the carb. Had a little piece of rust blocking it. Would idle great, wouldn't run under load. Jeff

[Sinistar556]

Check the jet again just to be sure, all clear.

Put it all back together and still nothing different. The more I think about it the more I think its a fuel pump problem. So, now I'm looking for some good tips and possibly a step by step on how o check that without too many fancy tools I have to go buy. Gonna search my literature too.

Thanks.

[alex77]

Did you take a look at the fuel pump
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91 mexibeetle

[rgm440]

Did you change the fuel lines after the fire? Did you take them loose from the fuel pump and maybe reinstalled them in reverse. Did the suction line to the pump get hot during the fire. I have seen the interlining of a fuel line collapse under suction and then alow fuel thru again after the pump is cut off.
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It's fun to be Crazy -- But damn it's expensive -- Besides - the devil made me do it -- make it a double this time

[jlex]

When it starts to stall out on you, can you give it a shot of starting fluid or gas down the throat of the carb to see if its fuel starved? IF that straightens it out, then you'll be on the right track to solving a fuel problem.
If electrical, is your distributor advancing correctly at higher RPM's? I would imagine you checked this when you checked the timing...
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jlex.
'70 std. "Elsie"
'88 Carrera

[DeathTrap]

Put a new $3 fuel filter on it.

[Sinistar556]

The fuel lines received no damage because I pulled them out to put the fire out. No leaks or anything from them and there is output from the pump when you turn the engine.

I have three distributors and caps and spent the better part of an hour swapping them around and trying all different kinds of timings. I can't really be sure what I should have the timing set at because I have an aftermarket engine and can't find a straight answer. I basicaly use the strobe and have my own 5 degree marks on the pully. Worked good before.

I'm gonna do the test suggested here by jlex in the morning as well as redo all the fuel lines on both sides of the chasis. Hopefully I'll get somewhere. Maybe I should start begging for a tester 30 pict-1 carb to see if I've been looking in the wrong place all along.

[chiprodriguez]

What kind of distributor? vac advance? Maybe the vac diaphram burned up inside an now not getting full advance. Timing an dwell are important. set the point dwell at about 45 and set the timing at 30 -32 degrees total advance and see what happens.

[Sinistar556]

Its a regular distributor, Bosch with red cap(paid extra for it), also tested a generic distributor as well.

I think jlex was right. I started it up this morning and let it warm up and it was still doing the same thing so I took the air cleaner off, got my carb cleaner and starter fluid, pushed the throttle and it started to bog down. I first tried adjusting the air/fuel with no effect. Then I did as the nice person on here said to do and as it was bogging down I shot some starting fluid into the carb and sure enough, it revved like new. I was so amazed I revved it again after and it bogged down again, let up off the throttle, pushed it again and shot more starting fluid in and it did it revved again. I call that a successful test with verifiable results.

Now the question is...whats wrong??! I'm gonna start with my trusty pipe cleaners and the carb(not the craft store ones, look it up, very cool). Anyone have any other suggestions as well as where and which are the best new fuel pumps?

[bigheadted]

Even though you looked at the diaphragm maybe it could not be working correctly, have you looked into the carb as you pump the throttle to see if fuel actually squirts in ???

[Sinistar556]

yeah, saw everything. If I had to guess I'd say something isn't letting the fuel go as fast as it needs to. I'm gonna have to do more poking around to see if I can figure out anything new.

[SkrapMetal]

I may have skimmed too fast, but I didn't read whether or not you changed your fuel filter.

Maybe you have a blockage in the line, or your pump isn't putting out.

You could try starting and running from a gas container.

When your car dies, instead of starting it again, remove the top of the carb to see if there is fuel in the float bowl.
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oo9less since 2007
-72 Ghia-

[jlex]

Sounds like you're getting close. If you have a fuel pressure tester, hook it up to see what the pump is (or isn't) doing.
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jlex.
'70 std. "Elsie"
'88 Carrera