Lately, my '74 1.8 with dual solex carbs has been stalling out. It is fine one day and bad the next. I start it up it, it is a little rougher that it used to be during the start. It idles decently for about 30-60seconds. Then starts to stumble then it gets worse and worse and worse. You get the point. Then it dies all together. The fuel pump seems to be making noise, an intermittent popping thumping kinda sound. Really hard to describe the sound. It feels really low on power during acceleration.

It has new fuel. and it ran fine 2 days ago. It doesn't seem to be temperature related. It felt like it was running out of fuel...It isn't. I figured the fuel pump has had it, but not so sure.

Please help

Thanks,
Sean

Step one, clean your idle jets.
Step two...when was the last time you adjusted your valves?
You would be amazed how much better these cars run after a tune up and how poorly they run prior.

With the cold weather here, a tune up will get you through the winter and cold season...plugs, points, cap, wires etc...

Rich

I'll give it a try, get back to you in a bit. I have no idea about the valves. I haven't adjusted them in the last month that I've owned the car. I have a 2.0 with fuel injection that needs a rebuild. Maybe by spring.......

If you have only owned it for a month...

Adjust the valves.
Do a tune up.
Clean the idle jets.
Change the oil.

BTW, Webers run like crap when its cold..in this weather its 20 minutes till the car is warm enough to let it idle without you feathering the gas pedal....
It can be less time, but you basically need to get in, drive 15 minutes and push the car hard till it heats up...
There are no chokes on webers, so there is no cold idle circuit...
They will spit, cough, and backfire for the first 10-20 minutes in this 30+ degree weather..

Rich

I did change to oil 3 days ago. It stalled once during warm-up. I let it warm up for a good 10min. I drove it to the ace hardware about 2 miles. I went another mile and started having troubles. The temp has been about 50-55 degrees all week so I figured it was something else. The first 3 weeks I had it I think it was colder and it had no issues at all. Maybe i ran it low on fuel and sucked something into the carb. I think I'll take the carb off and run some carb cleaner through it. They are single barrel solex (not sure which model #) probably off a VW. It's been 11 years since my last carb'd car, I'll have to refresh my memory on working on it.

Thanks,
Sean

Every carb has an idle jet somewhere.
Get the diagram for your carb...get the number off the carb...and clean it.
the idle jet can and does get dirty all the time...you need to learn how to clean it quickly.

If you get the part number and use google you will find the breakdown diagram (probably on a VW site)
From there you will find alot of decent advice on how to clean and setup the carbs.

Rich

Did you run low on gas recently?

Do you have a fuel filter? Has it been changed recently?

I've done it twice this year on my 911... fun.

Get a can of carb cleaner and have at the idle jets. I do it while the car is running so you can get an idea on progress.

I'm going to go down to this Porsche restoration shop down the road. He told me he has all kinds of extra parts laying around. Maybe he has a fuel pump and filter laying around. I'll clean my carbs and do a tuneup and see how it goes

Step 1: Clean Carbs including T-fitting between carbs and fuel pump.

Step2: Replace fuel pump. I'm thinking that since the fuel pump is making such an awful noise, it is the problem or will be. I didn't think to look to see if it even has a fuel filter. If so, I'll add one.

I'm leaving work to go to a Porsche restoration shop now. BYE.

Good luck, the clogged idles are a BIG issue...even my spanky new PMO's on the 6 had a couple and it ran like shit till I cleaned em out....now purrs like a kitten!

If I remove the idle jets, do I have to re-synchronize the carbs? Where is a good place to get the little float synchronizer thing for the solex carbs?

I didn't do a thing to it and now it's running fine. I'm gonna clean the carbs anyway.

no just pull em out clean with some carb cleaner and look to see they are not clogged. then put em back in (use a lil grease on the o rings before you 'snug' them down)

Josh

The idle jets weren't that dirty, but I got a little crud out of them. I also sprayed a little cleaner down the throat while revving it a bit. Eventually it got better. I put about 30 miles on it and it seems to be running better. Still not as well as it was when I get it a month ago...I chalk that up to the temperature change. We'll see how it does today.

By the way, are you a fellow Redskins fan?

could be gas related also...did you just get a new tank of fuel?

Also, pull the plugs and see if one of them got fouled.

Rich

I think when I ran it low on gas it probably sucked some crud into the carbs. I cleaned the idle jets and put some miles on it. Seems fine now.

Thanks for the help.
Sean

That's what I was thinking.

Get a good filter. I think there's a nice "one-in/one-out" canister from VW for some later cars (Rabbi, Jetta?) that might work great for carbs. A friend has been telling me about it and said he was going to drop one off. I'll try to get more info. Might even be a Diesel part.

Info:

It looks like it is cast from the same mold as the Porsche MFI filter but cleaner due to less fitting bosses. Mounting holes and dimensions are the same too. It does have a bleed screw. The filters are German made Perolaters. They have a water drain valve on the bottom.

Pics:

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I figured one of those cheap little inline filters that are sold in the same package as the "fuel pump for 914's converted to carbs". I think I saw it in the auto atlanta catalog.

Beats not having one at all but... a good quality filter could probably be had by calling a VW boneyard.

The plastic inlines go for $1-2 bucks.

Good luck with it.