Debugging stumble on acceleration when warm Options

[porschetub]

(IMG:style_emoticons/default/idea.gif) looks like your throttle body gasket isn't sealing,almost like the plenum is not flat in that area ?,that crack you have will fix up with a little JB Weld.
Other option is to goop it up will sealer run it and see ,in the mean time buy a used good plenum,good luck.

[solex]

The crack exposed... (IMG:style_emoticons/default/biggrin.gif)



and hopefully repaired. In the process of waiting for the paint to dry and then will reinstall.



I would like to learn to TIG weld... but will keep practicing to MIG weld

[porschetub]

The crack exposed... (IMG:style_emoticons/default/biggrin.gif)



and hopefully repaired. In the process of waiting for the paint to dry and then will reinstall.



I would like to learn to TIG weld... but will keep practicing to MIG weld

Well done on the welding...metal isn't very thick in that area,Tig may have been too hot anyway.
Make sure the TB and gasket are well sealed on the plenum,please report back after test run.

[solex]

Got everything installed new with new boots between the intake runners and the plenum. I added very little Loctite gasket maker underneath the TB gasket just incase it was not perfectly level

Adjusting the TPS was curious; I adjusted it on the bench measure resistance but it would always read a resistance until
(1) the middle wiper was past the gap and on the next trace on the lower part of the board
OR
(2) I got past the gap and would turn the TPS CCW

The contacts on the plastic arm are in contact with the post which will always measure a resistance.

I also tried the continuity adjustment measuring continuity until there is not and backing off 1 hash mark. This got be close but it was not until I adjusted the TPS by hand making sure that from idle I was able to mash the pedal with no bogging through the pedal range.

I guessing that we are all adjusting the TPS until the middle wiper is on the gap between the traces, I had to turn mine about 1 hash mark CW so the engine would rev smoothly when masking the pedal.

I set the timing to 10 degrees static timing at idle, measured the CHT 2.62kOhms at 75 degrees. The engine idles between 920 and 980 when HOT.

The drivability is night and day to what it was, I now see that for the most part most of the past 6 months debugging was chasing the vacuum leak at the plenum and the TB.

The car now accelerates smoothly although there is a very slight hesitation at 2800 & 3200 when I mash the gas pedal in 3rd and 4th but I can live with this as I generally do not drive like I stole the car.

I would be interest to know what advance curves on the 123 distributor you are all using particularly those with a 75-76 ECU.

Thank you all for your help

[porschetub]

Got everything installed new with new boots between the intake runners and the plenum. I added very little Loctite gasket maker underneath the TB gasket just incase it was not perfectly level

Adjusting the TPS was curious; I adjusted it on the bench measure resistance but it would always read a resistance until
(1) the middle wiper was past the gap and on the next trace on the lower part of the board
OR
(2) I got past the gap and would turn the TPS CCW

The contacts on the plastic arm are in contact with the post which will always measure a resistance.

I also tried the continuity adjustment measuring continuity until there is not and backing off 1 hash mark. This got be close but it was not until I adjusted the TPS by hand making sure that from idle I was able to mash the pedal with no bogging through the pedal range.

I guessing that we are all adjusting the TPS until the middle wiper is on the gap between the traces, I had to turn mine about 1 hash mark CW so the engine would rev smoothly when masking the pedal.

I set the timing to 10 degrees static timing at idle, measured the CHT 2.62kOhms at 75 degrees. The engine idles between 920 and 980 when HOT.

The drivability is night and day to what it was, I now see that for the most part most of the past 6 months debugging was chasing the vacuum leak at the plenum and the TB.

The car now accelerates smoothly although there is a very slight hesitation at 2800 & 3200 when I mash the gas pedal in 3rd and 4th but I can live with this as I generally do not drive like I stole the car.

I would be interest to know what advance curves on the 123 distributor you are all using particularly those with a 75-76 ECU.

Thank you all for your help

Excellent result,my experience with injection always tells me to look for air leaks before venturing into component faults first,the D-jet system is very sensitive to "false air " issues,I have no experience with this system but the principal is the same with any FI system.
The 123 distributor ?,I noticed someone else using 10 degrees static ,is that a requirement and do you dial back total advance to suit,just interested why such a high static advance, know little about these so just asking,cheers.

[solex]

Excellent result,my experience with injection always tells me to look for air leaks before venturing into component faults first,the D-jet system is very sensitive to "false air " issues,I have no experience with this system but the principal is the same with any FI system.
The 123 distributor ?,I noticed someone else using 10 degrees static ,is that a requirement and do you dial back total advance to suit,just interested why such a high static advance, know little about these so just asking,cheers.

I followed up with Ed at 123ignitionusa.com and he recommended 10 degrees static advance with curve 2; I checked the advance at 3500 rpm which came in around 28 degrees total advance which is just about right.