40IDF problems
 

I have a 2.0 with dual Weber 40IDF's; 200 air/115 main/ 55 idle; starts first crank; both carbs spew out the top and the driver side actually spews flames out the top (not good when leaning over to work the throttle cable); any ideas on what is going on? I have had a accelarator pump leak but fixed it from dripping with a little permatex (new diaphrams are on the way); what is interesting is that for a short time I had a single 32/36 on it and it spit back too, without flames. Valves were adjusted cold this morning, they are hydraulic (po, not my idea) to .006 intake and .008 exhaust; I have new points and condenser and a facet fuel pump; what else, the car is Bahia red if anyone thinks that could contribute to the problem. I am working on learning carbs so this will be educational for me; don't need to lose any more hair. Thanks ahead for the assistance.

Sounds like the problem is the valve adjustment you as hydaulic lifters don't have any clearance. The ones on my daughter's 914 are adjusted to zero lash plus some more. I forget what it is but your cam manufacturer can clue in. If it a Webcam then they are great to talk to. I would also make sure the timming is set to specs once the valves are done again correctly. I'd not run it anymore till you corerct it. Good luck.

Thank you; and I was so pleased with my valve adjustment; I have also learned from reading that the 009 distr. needs to go and be replaced with my 050; what are thoughts about the float needing adjusting-too much gas in the intake?

Was the car running right before? 115 mains seem kinda' lean. I run 125 mains and 55 idles w/200 air. I know if I lean out the carbs they seem to pop from starvation. Also will pop through the carbs if a jet is clogged.

The car has not been run on these carbs; I would like to up the main; where did you purchase yours? I thought there was a way to richen the mixture up some before I get the other main jets?

If you have a 050 distributor go ahead and use it otherwise I would get the valves set and then the total timming, then some jetting work. The 009 and 050 will have the same total advance the 009 has very little curve and it's main advantages are, it is cheap and simple with no vac lines to worry about. The drag racers like the 009 and I use one on my race car and to tell the truth I tried a 050 and could not feel any difference? Good luck

If you have hydraulics and adjusted them per solid lifter specifications, you're engine should sound like a can with bb being shaken. It will also wipe out the lifters in short fashion.

Hydraulics are adjusted to 0 lash and then anywhere for 1/4 turn to 1 turn down from 0.

Reversion in the intake tract ( spitting out the carb ) can be cam timing related. Excessive overlap cams at low rpm exhibit this. Cam profiles with severe opening and closing ramps, coupled with short intake runners can exhibit this.

It can also be a sticking valve.

It can be ignition timing ( charge is ignited while intake valve is still open).

Flames back thru the carb is not good. Check the ignition timing - it may well be overadvanced.

Are your plugs sooty or white on the insulators?

when you posted the component list for your induction system you did not mention a fuel pressure regulator. if you are running a facet type pump you need one. the excessive fuel pressure can wreck havoc with the floats and inlet valves, and with dialing your carbs in. while you may have to readjust your valves some of the rattling you hear is the fuel pump. if it is not isolated w/ some sort of rubber mounting system, it reverberates through the whole car. when i ran a facet more than one person told me i needed a valve adj. i usually did'nt bother with explaining about the hydrolic, just told them they may be right. it seemed these were the usually the same people that told me my 914 was just a fancy vw, not really a porsche, the pat response was "i didn't know that !". john connelly goes through the setup/dial in precedure pretty nicely at his site www.aircooled.net

kevin

Thanks for all the input; adjusted the valves to no rocking and then a quarter turn and boy the car is quiet. The spitting back through the carbs is less and goes away when idle is at 2000. I put on a 205 dist. and point/condenser; timed at TDC at 2000 idle; I assume the occaisional spit back is the lean mixture which will be corrected when I get 130 main jet this week. However, the car runs up to 40mph and that is it; does anyone think this lack of power is related to the main jet being 115, and that it will clear up when it is upped to 130?

Not to insult you, but BY A DAMN BOOK!. The timing on your car is 27 degrees advance at 3000 rpm, vacuum hoses disconnected.

With no advance, the damn thing ain't gonna run. If you set TDC at 2000 rpm, at idle (700 rpm) you are around 15 degrees retarded.

If the dwell on your points is not correct, the car won't accelerate.

If your muffler is plugged, the car won't accelerate.

About twice more around the block with you "guessing" at things is gonna cost you $2000 - $5000 for a new engine.

The book is a staggering $15.00.

One of these days I'll figure out why I put the mufler thing in.

:confused:

Yes, you are right, I got in a hurry, rather stranded transportation wise; your 'not to be an insult' reply cooled my jets; I have since settled down, and am using my brain instead of ... . I love looking like an idiot; does not happen often, but usually when it does it is public. I am getting correct jets, resetting timing, dwell and running a plumber snake through my exhaust.