New to me '76 Targa! Need help with webers!

[jmonitto]

Got yelled at for posting without an introduction. There she is! Just picked her up from a fellow Pelican member, just in time for summer! Very excited as I have wanted a Porsche since I was a child!


The car is a 2.7 on webers. I am having a heck of a time getting it run perfect. The webers were set up by the previous owner, and were supposedly running well. Car idles great, and has great power out WOT, but everything in between is less than perfect. Part throttle acceleration is very surgy and pops a lot. Light throttle cruising is also surgy, you can both feel and hear it stumbling.

Did some searches, and came to the conclusion that she needed to be richened up a tad. Turned the mixture screws out 1/4 turn, which didn't do much. Then went an additional 1/4. This helped the part throttle accel, and light throttle crusing, but caused the car to stumble in the transition from part throttle to WOT.

Not knowing where the mixture screws were in relation to fully in, I decided to start fresh, screw them all to the seat, then back them out 2 full turns (seemed like they were very far out). Car wouldn't even start. Went 1 more turn, car would reluctantly start, idle for 10 seconds, and shut down. Went 1 more turn (4 total turns) and the car would idle, but not well. To sum it up, I am now 5 1/4 turns out and the car is right back where I started.

PMO's site said that more than 3 1/2 turns means it needs bigger idle jets? Am I just much pickier than the previous owner?

Can anyone point me in the right direction as to where I can get more information on these carbs? I know how a holley works, and how to tune those, but am clueless about these. What special tools do I need to get this thing running right? I bought Weber Carburetors by HP books, anything else?

Finally, will I ever be completely happy with the webers? Is this going to be a constant battle to get it running right? Would going back to CIS be advisable, or should I just learn how to get the webers running right?

Sorry for the novel!

-Joe

[1976 TN Porsche]

Joe' Wellcome Pelican. Your car will run just fine with Webers. I would call Paul Abbout at Performance Oriented ( 530 ) 899-8371 He is the man when it come to Weber Carburators. He will talk you throught your Carburator problems. Give him a call. Craig. PS. Look him up on the web at Performance Oriented

[Joe Bob]

Exhaust analyzer and a unisync is a good thing....

[jmonitto]

Do you guys keep a wideband in the car, or are most of you using something like an LM-1 to tune them? I don't really want to have a flash AEM or other digital gauge in the car at all times.

[Hugh R]

Sorry I can't help on your motor, but from another Targa owner, welcome. What Joe Bob said about a Unisync. I used to use one on twin SU's on old British trash.

[mholbrook38]

Webers get complicated. So many variables. Agree Unisynch really necessary to tune but your jets and e-tubes may be wrong. Did you change altitude from where the car was before? That can make a difference. I wonder about your plugs as well. Have you been driving the car hard enough. I think it is easy to load up the plugs. You are most likely going to need some expert help and it would be most helpful to know the specs of the engine and the carbs.

Good luck, nice looking ride. Summer is good, no great!

[nikita76]

Hey Joe!

I agree with mholbrook38. With the car sitting since November, and started every so often...I think changing the plugs, cap, rotor, and stretching her legs for a bit will shake loose some of the cob webs.

Be well,

ND

[jmonitto]

So far, I've done an oil change (brad penn), cap, rotor, points, plugs, fuel filer, fuel system cleaner. I've been driving it as much as I can, but its misses so much at light throttle and cruise I am afraid I am going to do more damage than good. It runs great when you get in to the mains, and it free revs great. Its just when there is load and you are trying to drive it civilly that it does like it. It just seems to need a tune, but I do not know where to start!

[jpnovak]

4.5 turns out is not right. It sounds like they are not jetted correctly. should be 2 1/4 turns max if setup properly.

I suggest you pull the webers off the car, disassemble and document what jetting you have. Then post the results and we can help recommend new jets.