What kind of Solex is THIS ?

[NineLivesGT]

My Solex is idling (actually more like barely stumbling) at about 600 rpm, after the motor is warmed up. I won't idle at all until I let the motor warm up for 5 minutes. I tried and bump up the idle air screw on the Solex, but unlike the photos in my Clymers, Chiltons, and my original 71 factory Opel manual, this Solex has a tube that is part of the carb casting that is about 1 and 1/2 inches long that juts out where the idle air screw should be. The screw is not visible at all, appears to be inside of this tube? Could this be a later model Solex from a 73 that cannot be bumped up? If I loosen (counterclockwise) the screw even a tad, it won't idle at all. I can only tighten it back (clockwise) to where it was idling originally, at 600 rpm, and it won't turn any more. Has anyone ever seen a Solex like this on a GT? The car is a 71 GT, but has held some "surprises" as I work on various parts of the car. (The trans turns out to be from a 73, for example. The new '71 back up light switch I bought cannot be installed, I just found out, because there's no place to put it in the tranny. The later models had different b/u light switch arrangement and wiring, from what I've gathered from this forum. Guess I'll just have to mickey mouse some wacky b/u switch arrangement to pass inspection. Any old Opel mechanics out there who know any tricks on bumping the idle speed up on this later model (I'm guessing that's what this thing is) GT Solex carb? It's got new plugs, wires, and it runs really smooth, excellent, actually, if I hold the pedal at about 900-1000 rpm. The carb doesn't leak, has been professionally rebuilt. It just idles too low.

[namba209]

If your car likes to idle at 1000 RPM, set it up that way, or at least to where is will remain at idle without dying. It may be a little fast but at least it won't die on you at a stop. The Solex carbs are just too hard to maintain, one reason in my estimation is the pot metal is too soft, continually running fuel throug the passages erodes them in a relatively short time so it is impossible to keep them in tune. Just my $.02.

Ron

[NineLivesGT]

Thanks for the reply Namba. Problem is I CAN'T seem to get the warm idle up to 1000-1200 RPM. I was hoping a '73 GT owner could confirm that this carb is from a '73, and how they usually adjust warm idle speed on the 73 carb. Manuals all say turn idle air speed screw left to increase, but engine dies if I do that even a tad. Could be just that I have a big vacuum leak somewhere, so if I try and bump up idle air speed, the motor is already getting too much air from the vac leak, and thats why it dies??? When I step on the brake pedal, unless I also step on the gas and keep the revs way up, the idle quickly drops down, and then the motor dies. Am I looking at a major vacuum leak here? Doesn't seem to be a voltage issue, because when I turn on lights and other accessories there's no change at all in the idle. This was my first post to the forum, am surprised none of the amazing Opel wizards in this forum could help. I can't drive the car until I figure this too low idle problem out. Maybe I should just trash the Solex and get a Weber. What's the best Weber for a 71 1.9 ? Oh yes, here's my brother's advice: "just duct tape a block of wood to stop the gas pedal from coming all the way back up so it idles higher and doesn't die". Well, I suppose that would work, but... uhh, well maybe I can get some better advice than duct tape.

[Gary]

I did a site search for solex (70 posts) and vacuum leak (18 posts) You may find an answer there.

I'm 3 towns away from you, if you run into problems, give a holler.

[madhatterpdc]

Your best resource is to run searches on the past posts.

The (32/36) Weber is the way to go for all stock 1.9 configs and some mild performance work. Anything more than mild and you'll want to consider a 38 Weber (but the 38 isn't your best bet on a stock config). The Solex's are very flaky to say the least. Some are good, some are bad, most are marginal.

I would check in the following order. Vacuum Leaks, fuel leaks (unlikely, but worth a look), ignition timing (and vacuum advance of the timing), carb float stuck? mixture screw, try and lean the idle jet a touch.

You are also going to want to figure out if the idle screw is stuck. You really should be able to set that screw so the engine idles at 2000 rpm if you were to screw it all the way in.

Don't take my word as gospel by any means, I still have a lot to learn, but these are just a couple ideas that come to my mind. The Opel Wizards my have a tip or two, but they can only do so much to help.

[Old Hippie]

Looking at my English version Opel book (1974) and your description......hmm, a Solex 32.TDID? seems to be the only one in there. Don't know if that helps or not. It does say, on a cold engine: before starting, fully depress the gas pedal once to set the throttle vale linkage to it's highest point of the choke cam.

[Gary]

Hey, 3 posts in a row from Southeastern Massachusetts. I thought this was a global site.

[baronbors]

If you kill the engine when you hit the brake- your brake booster is shot and leaking at the seal. Replace it and I bet your idle problem goes away.

[greensmurf20]

try to find a way to block off the vaccum on the intake for the brake booster, just to be sure its the booster, not a line or something of the sort. you will just loose power breaks. this will give you time to adjust the carb right until you can get a new booster because like baronbors said, its almost the booster for sure.

[greensmurf20]

also, if you need a booster i have one that came off my GT. the MC was leaking and i didnt know where from so i just changed the booster and MC from a part car and my leak ended up being from the resivoir tank and the booster worked well.

[baz]

hi 9Lves

just a thought, the carb wouldnt be a PDSI single choke would it ?
if so its off a 1600 opel and wont work to top revs also
unless the previous owner has found a 1600 to replace a dead engine
if so then check with rallybob to see if its good for tuning on a 1900 block for higher compression!

[NineLivesGT]

Thanks everyone for the help. Will check brake booster line and for vac leaks and then timing, as Madhatter suggests. Meanwhile, I have been reading everywhere about the advantages of going with the Weber 32/36. A friend said he put one on a '72 BMW 2002 that he owned years ago, and it was a straight bolt on, swap it and go. Said it made a huge difference. All else fails, the Mr Solex shall be meeting Mr baseball bat very shortly.

Thanks again everyone. This car has been through hell and back, and it looks the part, believe me. People can't even believe it starts up, much less that it still drives. Even though I just bought an '02 Miata, I'm not giving up on this old girl. Gary, thanks for your invitation. I think I should be OK though. Saw your GT in traffic on Route 6 a couple of yrs ago, it's a beauty.