power surge and banging out when driving HELP!

Ok now I have a power serge after you build up a few rpms then at constant speed say 3-40 mph it is popping and cutting out a little.
What should I look for and where should I look?
Thanking you in advance.
Jerry

What are you running for carburetors?

Remember your last post I asked about "Popping". If it's "popping" back through the carb(s) something is restricting fuel into your carb. Dirty jet etc...(sticking the neck out far here) It's not fuel pump psi or fuel line to pump issues. I've had rust dust (yes that's right) block fuel at the inlet needle/seat. It would flow enough at idle (no trouble), then it felt like I was pulling a trailer as I accelerated. Is it popping back through both carbs (if you have two) or just the one?
What type of carbs do you have? Did anyone tune? touch? adjust? anything recently?

If "popping" only at constant speed, I'd also be lookin for an air leak on the intake side, at manifold or head. It doesn't take much.

Exhaust leak?

If you have Webers it could be the evil clogged idle jets. Has the car been sitting for a while? Have you washed it recently?

Did you lock a small child in the engine bay?

Or maybe the "Engine Monkey"?

http://i49.photobucket.com/albums/f254/speedster356/bongo.gif

Thanks again for all of your valuable help. The car had sat for 12 years before I got it. The webbers had been rebuilt and supposedly the gas tank had been cleaned and new fuel lines installed.
The idle jets were clogged and now it seems to be running great. Also had to get the chimp out of the trunk he made to much noise when I drove around town I was getting strange looks from the dog walkers.

Thanks again for the help.

Jerry

Jerry, Did you clean the jets yourself? Was the debris magnetic?

Hello Bruce,

I had it done at the VW shop and I will ask them if they noticed if the debris was magnetic or not, But you know how that goes, they may or maynot have noticed anything like that.

Jerry, your shop probably already did this, but the hard line that enters the tunnel in front of you and comes out on top of the frame horns behind you is sometimes the culprit.
In a car which has been left sitting for as long as yours was, it sometimes happens that the lines are drained and rust flakes develop in them. Short of running a new hard line, the best preventive maintenance for your carbs may be to cap the soft lines and squirt some brake cleaner or other really tough solvent into the lines and then chase it out using compressed air.
Repeat the treatment, switching ends with the air blower. Make sure to rubber-band something like a coffee filter or a handkerchief over the end of the line on the other end, and try to remember to put a garbage bag loosely over the end of that.
The metal flakes might not be big enough to see, but they'll sure jam up an idle jet. The peice of cloth (or the coffee filter) will allow you to see if flakes came out with the solvent.

Thanks Cory, I will talk to the shop about the line and see what they did or didn't do.

Any updates?

ha jerry any luck yet? it must be that south of the boarder sand! (BAD STUFF) STEVE

if ever this happens again-(if)---drop a few radio shack magnets in your fuel bowls while the carbs are apart. It attracts the rust dust from that 12 year old tank and won't clog your jets.

On both my twin carb engines I had to match the right and left throttle levers they were a little off. Thus causing one carb to have more lever travel than the other and to result in popping just off idle. or a surge at certain rpm's. the right and left carburetor throttle flap travel must be exactly the same.

If I jus repeated someones post.. Sorry it's late and i to tired to read everything.

With all the crap out their on the market It seams you have to check every single little detail. even the spark plug boots that go on the plug wires .. It's getting to the point you have to spec out every single part to get a decent running engine. I blame China for that..

Hey Guys, Thanks for all of the excellent advise and help. As usual all you have to do is ask and everyone is ready to offer help or advise.
I found a super mechanic here in Northern Occupied Mexico, he is a porsche racing mechanic and he had my little bug engine running like a top in one visit. I have put him on retainer, well not retainer, but would like to. I told him any time he is off to the races he has to call me first to see if I need my car fixed. He assured me that he would. Do you think he was serious?
Thanks again for all of the help.

What was wrong and how'd he fix it?

Ahh . . .but if he revealed THAT he would no longer be a "super mechanic"! I've got one of those that I use myself whenever realy baffled.

Just recognizing what is realy happening, based on his years of experience, is what you pay for.

How does that old diddy about the repairman's itemized billing go?
"$10 for hitting the engine with a hammer to get it started. $100 for knowing where to hit it."

david said, "$10 for hitting the engine with a hammer to get it started. $100 for knowing where to hit it."

:) Excellent.....

I would have liked to here what the problem was. That's how you learn the quirky stuff..

That'll cost you a cool $100 Barry.

David why do we have a forum. If we cant use it to learn.

Talking poop will only get you noticed (Thats) the easy part..

Backing it up with facts . Is when you keep the attention.and those are the true friends in my circle.

Yeh, the original post says..."What should I look for and where should I look?". OK, for whatever the reason I, too, am curious as to the solution to the problem. No need to divulge anyone's trade secret, just a generalized clue would be appreciated. I think I can fill in the blanks myself or, if not, at least ask for somebody's help. Thanks.

Read reply #7, clogged idle jets plus the car had been sitting for 12 years.

OK got it. I somehow thought the "fix" wasn't final. I read through the threads too fast; the answer was staring me in the face and it didn't sink in.

Sorry, The mechanic told me it was in the carbs and the timing but he didn't go into any detail from there just grinned and said it was fixed. He even rebuilt the brake lock that was installed in the little speedster and saved me $450.00 for new rear calipers, cables and all related parts so I could have an emergency brake.
It really is nice to find someone, as I am sure most of you are capable of doing the same repairs yourself, but I'm not, that know what they are doing and then do it and don't charge you an arm and a leg. Just an arm.
Thanks again.

Barry - that was a joke. Sorry you didn't notice that.

Jerry: ..."just grinned and said it was fixed.".....
In mechanic-speak that means he re-connected a loose wire, then billed you $450.
(just a small joke; don't nobody get cranky now..)

Not a problem,, I'm fine with that. the trash in the jets sounds, right..

I've been distracted the last few days by my job saga again.. It's getting rougher than John Wayne toilet paper.

Tough it up, Pilgrim. Got any pine needles in your neck of the woods?

If it gets that bad I'll use brushed corn cobs.