IDA3C Weber Troubleshooting Options

[930cabman]

My goal today was to do the tach stuff so I could see what my RPMs were at and do some more tuning, but that took a turn and instead I pulled the pedal board for rebuild and attached the new throttle cable. Also picked up my 911 front suspension from storage and will need to look into rebuilding all of that. No movement for engine today.

funny how easy to get sidetracked with these 1/2 century beasts. Unless you go through every nut/bolt it's near endless. But we come back for more punishment over and over

[Cfletch]

Kind of going back to this now that my suspensions fully installed and I am waiting on the last of the brake parts so I have get that squared away. I needed to pull the gas tank to do some welding in the frunk area where the tire goes. There was some rust holes there and I decided to change my fuel pump to the rotary ones that are internally regulated at 3.5lbs instead of using my leaky kind of crappy regulator I didn't like much. Anyway I swapped that out, verified my pressure on the other end and that was good. I also got new plugs (NGKs) instead of the old Bosch ones that were in there prior to me getting the engine. I tried to start it and it ran realllly poorly. I pulled 1 of my plug wires and the Beru fitting (correct terms) basically exploded, springs and resistors went everywhere and the end got stuck on the plug. I spent about a good 2 hours fishing all that stuff out from a few cylinders because that happened multiple times. Because of this I decided to just get some new wires from Clewett and then tried to start it up. Again, it ran really poorly. It seemed like it was missing from various cylinders at a given time and its been hard to pinpoint what from all this change.

Here are the new parts in total:

Rotor- resistor-less from a 70s bug, correct height and what not. Checked resistance and there's none.

Original cap- I ordered a new one that is really bad quality and so I'm sticking with my original one I have for the car.

Spark plugs- ngk bpr6es

Wires- Clewett

This time around I noticed oil shooting out from the crank case hose, crank case neck on the engine which makes me suspect I have overfilled my engine oil and that is being exacerbated by the fact that the car is not currently level since I was doing that welding on the front. Nose is up.

Would the oil level be causing this weird untraceable misfire I seem to be having? At idle it does not run too great, but it idles. At higher RPM I'm flinging oil from the breather and it seems to run ok at higher but not perfect or great.

I pulled a plug from a lower temperature cylinder (measured the exhaust headers) to check its spark and at first 2 or so cranks it didn't fire, but then started really sparking good, I'm starting to think the Oil is causing the plugs to foul out at low RPMs and is the source of my problems

[mb911]

Does it smoke a lot? Wires in incorrect location? Plugged idle jets? Oil level could effect it but very unlikely if it’s not smoking a lot as the oil didn’t make it past the rings.

[Cfletch]

It definitely smells rich and is smoking a decent amount. There's a clear constant misfire at say 1/4 throttle/ 2k RPM or so. I would say the caps correct but I will 3x check next I go out to mess around with it.

Debating in pulling the carbs again to clean out with compressed air in case something is clogged from the fuel pump swap. I'll do that after draining some oil and making the car level again.

Any other suggestions?

[mb911]

It definitely smells rich and is smoking a decent amount. There's a clear constant misfire at say 1/4 throttle/ 2k RPM or so. I would say the caps correct but I will 3x check next I go out to mess around with it.

Debating in pulling the carbs again to clean out with compressed air in case something is clogged from the fuel pump swap. I'll do that after draining some oil and making the car level again.

Any other suggestions?

Floats sticking?

[Cfletch]

Ok, drained about a quart from the engine drain and put it back down on the ground, engines now running back on all 6, but very rich so I'm kind of back to square one. Seems that with the pump swap I must have gotten some sediment stuck in places it shouldn't be on the carbs and I have really poor transition and idle. Going to pull them tomorrow to blast them all out with air hope that things are a little better so I can begin to tune.

[Cfletch]

Ok everyone back here with you guys, I pulled the carbs and blasted them all out with air once again and then set everything back to a baseline per Paul Abbott (Performance Oriented). I am still having some weirdness that I cannot really explain.

I can get the car to idle just fine around say 900 or so, but if I give it some throttle, say about 3k rpm worth, the car will not go back down to the idle. I have checked Vacuum leaks, don't think its that because I can get the car to stay at 900 prior to messing around with the throttle as well as I sprayed some carb cleaner around the bases of the manifolds and got no RPM change. It kind of just seems to stick at a given RPM and will not go back down unless I turn it off and start it back up. Even then its a little hard to start back up again unless I give it more gas than I should for having some good temp in the engine. There is no real rhyme or reason behind this. I then suspected maybe the shafts are messing with me, but everything feels pretty tight and good.

I had read that if the weights in the distributor were sticking then that would cause a hard start issue as well a irregular idle in terms of where it would sit if the idle screws were in a standard spot.

Any thoughts here or tests I could perform to check the springs if that seems like a possible reason why I have the issue?

[brant]

Did you spray carb cleaner, while the motor is running on the butterfly shaft of that carb?

[gereed75]

Elementary question here but worth confirming - When the idle goes high are you certain that the throttle levers are indeed back seated on the idle stops? There can be friction in the linkage set up and without the right springs the throttle plates can stick slightly open, obviously causing erratic idle. Could also cause the variation side to side in airflow measurements that you have experienced.

If all that checks out, and with all of the work that you have done on the carbs this all could indeed be caused by a distributor/ timing issue.

[Cfletch]

Did you spray carb cleaner, while the motor is running on the butterfly shaft of that carb?

No, not directly on the shaft itself, but at the base where the carbs attach to manifold as well as manifold to head.

Elementary question here but worth confirming - When the idle goes high are you certain that the throttle levers are indeed back seated on the idle stops? There can be friction in the linkage set up and without the right springs the throttle plates can stick slightly open, obviously causing erratic idle. Could also cause the variation side to side in airflow measurements that you have experienced.

If all that checks out, and with all of the work that you have done on the carbs this all could indeed be caused by a distributor/ timing issue.

I am pretty certain I eliminated any hang ups on the throttle that could be induced by binding linkages or weak springs. I eventually disconnected the crossbar and hit both throttles by hand at similar speeds to verify I still had the same idle issue, and I did. Also I had pulled up on the linkage to attempt to force close them any further if there was an issue with the springs and that did nothing, they were fully seated/closed.

Not sure if this really was the case, but the issue seemed to present itself once warmed up, prior to that it seemed okay and I was just waiting for the engine to warm up to start getting some tune out of the carbs on the adjustment screws.

[930cabman]

Are you using a snail to confirm air flow at idle?

these buggers can be tricky, but once mastered are great

[Cfletch]

Are you using a snail to confirm air flow at idle?

these buggers can be tricky, but once mastered are great

Yes I have the snail

[brant]

Did you spray carb cleaner, while the motor is running on the butterfly shaft of that carb?

Worn throttle bushings can create a source of vacuum leak and effect idle.
Run the test with carb cleaner on the throttle shafts

[930cabman]

Are you using a snail to confirm air flow at idle?

these buggers can be tricky, but once mastered are great

Yes I have the snail

you are getting 3.5 - 5 across the 6?

and the linkage is disconnected from the cable?

[Cfletch]

Are you using a snail to confirm air flow at idle?

these buggers can be tricky, but once mastered are great

Yes I have the snail

you are getting 3.5 - 5 across the 6?

and the linkage is disconnected from the cable?

Generally yes right around there, slightly higher, 6 in some spots but I didnt really get to the point of tuning that to be better balances at this point because of this idle stuff. I'm planning on pulling the distributor to check that out and potentially upgrade to 123 if needed.

[Cfletch]

Did you spray carb cleaner, while the motor is running on the butterfly shaft of that carb?

Worn throttle bushings can create a source of vacuum leak and effect idle.
Run the test with carb cleaner on the throttle shafts

Prior to me pulling the distributor, I'll confirm by directly spraying the shafts to see if there's any indication of a leak there.

[brant]

Did you spray carb cleaner, while the motor is running on the butterfly shaft of that carb?

Worn throttle bushings can create a source of vacuum leak and effect idle.
Run the test with carb cleaner on the throttle shafts

Prior to me pulling the distributor, I'll confirm by directly spraying the shafts to see if there's any indication of a leak there.

Great

[Cfletch]

Ok quick update for you guys:

Went over to the car after work, started it and it took a few tries, but then started and ran at around 900 rpm idle no problem. I then sprayed more cleaner at the shafts on each end and underneath where you can see the link between each throat, no change in idle. I then jabbed the throttle and it got hung up again at 2k, this time the engine was on the colder end of things so i dont think engine temp itself has much to do with my issue. I decided to then just pull the distributor and see what was going on. After getting it on my bench, I noticed the shaft itself has a lot of up down play, maybe 1/2 inch or so. I feel like this is really excessive. Also the top plate was stuck. I messed around with the shaft and pushed it back down into a seated position and the plates then moved freely more or less once I disconnected my vac retard. I took a look under the felt inside the shaft and this little c clip was loose and flopping around inside. I figured this eliminated the up down play and so I tried to get it reinstalled and something must have been up with it to begin with. I got it installed and the play went away or close to non, maybe 1/8th inch and that seemed fine. Put it back in the car annnnddd no spark at all. Nothing. So I figured I had messed up my pertronix setting because I was checking if my light was firing at all and it didn't. Pulled it out again and the clip must have fallen out of its groove inside the top of the shaft because all of my play was back and the binding of the plates was back.

After all of this I think I am due for a 123. I dont want to deal with mechanical failures in the future and it would have a better curve for my no carb'ed nonCIS engine as it is.

I have a little vid I can send if anyone was intersted, its just of the car idling and popping out the exhaust presumably because the advance plates were stuck. PM me your cell number and can send if interested.

I'll be going to car week so no more progress for this weekend sadly.

[930cabman]

Ok quick update for you guys:

Went over to the car after work, started it and it took a few tries, but then started and ran at around 900 rpm idle no problem. I then sprayed more cleaner at the shafts on each end and underneath where you can see the link between each throat, no change in idle. I then jabbed the throttle and it got hung up again at 2k, this time the engine was on the colder end of things so i dont think engine temp itself has much to do with my issue. I decided to then just pull the distributor and see what was going on. After getting it on my bench, I noticed the shaft itself has a lot of up down play, maybe 1/2 inch or so. I feel like this is really excessive. Also the top plate was stuck. I messed around with the shaft and pushed it back down into a seated position and the plates then moved freely more or less once I disconnected my vac retard. I took a look under the felt inside the shaft and this little c clip was loose and flopping around inside. I figured this eliminated the up down play and so I tried to get it reinstalled and something must have been up with it to begin with. I got it installed and the play went away or close to non, maybe 1/8th inch and that seemed fine. Put it back in the car annnnddd no spark at all. Nothing. So I figured I had messed up my pertronix setting because I was checking if my light was firing at all and it didn't. Pulled it out again and the clip must have fallen out of its groove inside the top of the shaft because all of my play was back and the binding of the plates was back.

After all of this I think I am due for a 123. I dont want to deal with mechanical failures in the future and it would have a better curve for my no carb'ed nonCIS engine as it is.

I have a little vid I can send if anyone was intersted, its just of the car idling and popping out the exhaust presumably because the advance plates were stuck. PM me your cell number and can send if interested.

I'll be going to car week so no more progress for this weekend sadly.

The distr was advancing?

had nothing to do with the carbs?

[Cfletch]

Ok quick update for you guys:

Went over to the car after work, started it and it took a few tries, but then started and ran at around 900 rpm idle no problem. I then sprayed more cleaner at the shafts on each end and underneath where you can see the link between each throat, no change in idle. I then jabbed the throttle and it got hung up again at 2k, this time the engine was on the colder end of things so i dont think engine temp itself has much to do with my issue. I decided to then just pull the distributor and see what was going on. After getting it on my bench, I noticed the shaft itself has a lot of up down play, maybe 1/2 inch or so. I feel like this is really excessive. Also the top plate was stuck. I messed around with the shaft and pushed it back down into a seated position and the plates then moved freely more or less once I disconnected my vac retard. I took a look under the felt inside the shaft and this little c clip was loose and flopping around inside. I figured this eliminated the up down play and so I tried to get it reinstalled and something must have been up with it to begin with. I got it installed and the play went away or close to non, maybe 1/8th inch and that seemed fine. Put it back in the car annnnddd no spark at all. Nothing. So I figured I had messed up my pertronix setting because I was checking if my light was firing at all and it didn't. Pulled it out again and the clip must have fallen out of its groove inside the top of the shaft because all of my play was back and the binding of the plates was back.

After all of this I think I am due for a 123. I dont want to deal with mechanical failures in the future and it would have a better curve for my no carb'ed nonCIS engine as it is.

I have a little vid I can send if anyone was intersted, its just of the car idling and popping out the exhaust presumably because the advance plates were stuck. PM me your cell number and can send if interested.

I'll be going to car week so no more progress for this weekend sadly.

The distr was advancing?

had nothing to do with the carbs?

For this most recent update yes I think its just a distributor issue causing a stuck advance mechanism. For all the prior stuff earlier mentioned I think those are all tackled now(?) Hard to say because I have changed so much and then this issue seemingly popped up or at least has become more of an issue because my other ones had been resolved.

At least for now since I cannot even run the car to further diagnose my carb issues