Easy as 1 2 3, Got it yesterday, pushed all projects aside! Options

[JoeD]

Also been running a 123 on my 2270 dual-carbed Raby motor since January. It's been fantastic- rock solid, performs great. Putting one on my '70 Datsun 240Z next.

[mgphoto]

So the miss I find is a loose injector connector, yeah remember D-Jet connectors.

I've been taking the car on 20 to 30 mile test runs, dealing with ambiant temps and fuel octane.

There has been a real Jeckell and Hyde situation, one run good and strong, another lots of ping and no power at WOT.

I started to lean to the temp issue. Until yesterday, we had 99 to 102* F I took the car for an 80 mile run through a few stressing circumstances.

After 6 miles, engine not even up to running temps she felt like, I've heard the English use the term "lumpy."

I was heading into a downhill section of the 14 FWY north, I pushed the throttle to max, she responded.

From that point on she was Jeckell! The temps outside were brutal, but as long as I was hitting 85 most of the time the breeze was nice.

Since the loose injector wire I've done nothing under the hood except adjust the idle using the air bypass screw, which has been varying from 600 to 1300 RPM. So after reading another 123 post, I will start expermenting with removing the retard vacuum line. I had a problem with low idle with the headlights on, doesn't help the lightend flywheel any.

Here is where I start to examine the fuel issue. After an internet search for Summer/Winter fuel blend info. Did you know that they add butane to gasoline in the summer months.

My normal fuel is not the best gas ever, so I suspect this might be the issue.

I found some 100 octane "race fuel" at a Sonoco station in Pasadena.
I have been mixing that with the 91 octane. By blending both fuels I been able to find a point that makes the car run without pinging.
Yesterdays blend was about 94 octane. Even with stressing the engine with full throttle uphill acceleration no pinging. I did hear a singular ping on occasion, seemed to happen between off throttle and WOT at 3500 to 4000 RPM.
Oil temps never went over 215* F.


Next I will burn off the 94 octane and use a high quality 91 octane.
When I get what I consider a stable ignition I will begin checking the FI with the AFR meter.
Stay tuned.

[VaccaRabite]

Sounds like you are well on the way.
I hate electrical gremlins. So hard to track and fix.

The low idle with headlights - did you fix that? That will not be helping you tune, and could be part of your issue. Could be dirty grounds (or dirty contacts raising resistance in your wire harness). If thats the issue, it could be pervasive.

Have you considered taking the car to a dyno and having it tuned there? I was very slow to accept this, and Mark opened my eyes to it. I'm so sold on it now.

Zach

[mgphoto]

We all have a need to see.

[mgphoto]

Don't know why they are 90* off in the post but correct when viewing the image alone.
Here is the 123Porsche-4-R-V-IE advance selection port.

[mgphoto]

FYI type 4 needs a spacer which should come with the unit.

Shaft on the Bosch unit is not as long as the 123 hence the spacer.



Hey they look right on my dam phone!

[BeatNavy]

Cool, thanks for the pictures. So now I know it's advance curve "b" when mine arrives (IMG:style_emoticons/default/smile.gif)

So the miss I find is a loose injector connector, yeah remember D-Jet connectors.

I've had that happen to me a couple of times in the last few weeks (IMG:style_emoticons/default/dry.gif) . Need to figure out what the "trick" is (e.g., getting those little "boots" over the injectors...?)

[mgphoto]

Cool, thanks for the pictures. So now I know it's advance curve "b" when mine arrives (IMG:style_emoticons/default/smile.gif)

So the miss I find is a loose injector connector, yeah remember D-Jet connectors.

I've had that happen to me a couple of times in the last few weeks (IMG:style_emoticons/default/dry.gif) . Need to figure out what the "trick" is (e.g., getting those little "boots" over the injectors...?)

Hey BeatNavy,
I might change the curve after I do some more research and remove the retard vacuum line.

Use the boots, if you got them. The original style has pull tabs on either side of the boot. Newer Bowsby style doesn't have the tabs, but the rubber is newer and much more supple.

[mgphoto]

I took her out for an early spin on Saturday, 68*F ran like "Jeckell" BOY HOUDY...

Using up the last 3 gals of the 94 octane, mostly 14 fwy, 85 mph uphill

I decided to remove the vacuum retard hose and cap the throttle body, I did have idle issues. I tried to get the best balance between day and night, driving lights off and on.

I seem to have an issue with "hot start," five to ten minutes in a store to pick up something and wham.
My usual procedure is to press the throttle and feed some air, but that was not working. Getting the engine to start was a bit more difficult. I needed to floor the accelorator pedal holding it until the engine fired and than feathering the pedal so the engine wouldn't stall, not what I call ideal. But after a minute or two a stable idle.

Ok after a good 60 + mile ride, time for fuel. Second Wind sugested Chevron premium 91 octane, as a good quality gas, so 8 gals of 91, outside temps low 80's*F.
Out of the station and right onto the freeway on ramp, and floored the accelorator and wham, ping, lots of it!

So immediately there is a change, it is directly related to the octane of the fuel.
Next test is to drive in a lower temperature environment to see it the ping is present at mid 60's*F.
I'm going to wait till the moisture clears up a bit here in Los Angeles as a storm moves through.


What I may need here is some advise as to what I can do to run without ping using pump fuel.
I'm in L.A. it's a good 30 mile trek to get some of the 100 octane "race fuel" and real fuel additives as octane boosters are not to be found on the shelves of the general flaps.

[Mblizzard]

I took her out for an early spin on Saturday, 68*F ran like "Jeckell" BOY HOUDY...

Using up the last 3 gals of the 94 octane, mostly 14 fwy, 85 mph uphill

I decided to remove the vacuum retard hose and cap the throttle body, I did have idle issues. I tried to get the best balance between day and night, driving lights off and on.

I seem to have an issue with "hot start," five to ten minutes in a store to pick up something and wham.
My usual procedure is to press the throttle and feed some air, but that was not working. Getting the engine to start was a bit more difficult. I needed to floor the accelorator pedal holding it until the engine fired and than feathering the pedal so the engine wouldn't stall, not what I call ideal. But after a minute or two a stable idle.

Ok after a good 60 + mile ride, time for fuel. Second Wind sugested Chevron premium 91 octane, as a good quality gas, so 8 gals of 91, outside temps low 80's*F.
Out of the station and right onto the freeway on ramp, and floored the accelorator and wham, ping, lots of it!

So immediately there is a change, it is directly related to the octane of the fuel.
Next test is to drive in a lower temperature environment to see it the ping is present at mid 60's*F.
I'm going to wait till the moisture clears up a bit here in Los Angeles as a storm moves through.


What I may need here is some advise as to what I can do to run without ping using pump fuel.
I'm in L.A. it's a good 30 mile trek to get some of the 100 octane "race fuel" and real fuel additives as octane boosters are not to be found on the shelves of the general flaps.

Of course the obvious is to reduce the timing a bit.

On the 1,2,3 I found that the cap could move around a bit and add a few degrees of timing to the problem just by knocking it about. Something to check for sure.

Also may want to check your compression to be sure that you have equal values across.

[mgphoto]

I took her out for an early spin on Saturday, 68*F ran like "Jeckell" BOY HOUDY...

Using up the last 3 gals of the 94 octane, mostly 14 fwy, 85 mph uphill

I decided to remove the vacuum retard hose and cap the throttle body, I did have idle issues. I tried to get the best balance between day and night, driving lights off and on.

I seem to have an issue with "hot start," five to ten minutes in a store to pick up something and wham.
My usual procedure is to press the throttle and feed some air, but that was not working. Getting the engine to start was a bit more difficult. I needed to floor the accelorator pedal holding it until the engine fired and than feathering the pedal so the engine wouldn't stall, not what I call ideal. But after a minute or two a stable idle.

Ok after a good 60 + mile ride, time for fuel. Second Wind sugested Chevron premium 91 octane, as a good quality gas, so 8 gals of 91, outside temps low 80's*F.
Out of the station and right onto the freeway on ramp, and floored the accelorator and wham, ping, lots of it!

So immediately there is a change, it is directly related to the octane of the fuel.
Next test is to drive in a lower temperature environment to see it the ping is present at mid 60's*F.
I'm going to wait till the moisture clears up a bit here in Los Angeles as a storm moves through.


What I may need here is some advise as to what I can do to run without ping using pump fuel.
I'm in L.A. it's a good 30 mile trek to get some of the 100 octane "race fuel" and real fuel additives as octane boosters are not to be found on the shelves of the general flaps.

Of course the obvious is to reduce the timing a bit.

On the 1,2,3 I found that the cap could move around a bit and add a few degrees of timing to the problem just by knocking it about. Something to check for sure.

Also may want to check your compression to be sure that you have equal values across.

Seems the clips holding the cap on are not as "beefy" as a stock Bosch unit.

I don't seem to understand why reducing advance would help with ping other then the engine not running as hot?
I think that changing the advance curve might be a better option than detuning the engine? Simply a selection on the 123 dizzy.

[pete000]

If the car did not ping with the stock distributor I would suspect the 123 unit is programmed more aggressively or just too much timing along of the curve.

Have you verified the advance with a timing light? A programmable timing light with RPM read out can help you determine where your at now through out the rpm range. The high octane will compensate for too much advance but at a high cost and inconvenience.

VP Racing Fuels on Western Ave and PCH sells race gas in any configuration you would want.

Have you verified fuel pressure? checking AFR would also be a good idea as you might be too lean which could lead to ping.

I am curious as was there ping before the 123 unit?

(IMG:style_emoticons/default/popcorn[1].gif)

[Rand]

I don't seem to understand why reducing advance would help with ping other then the engine not running as hot?

Early spark is the most common cause. Cylinder pressure rises too rapidly.

[DRPHIL914]

i agree that your timing has to be off but also you should not have to be running 100 octane in a stock motor. the original designers of this motor intended 87 octane fuel in a stock motor.
you need correct fuel- pinging is pre-ignition- the fuel is igniting before it should before or after, it is supposed to, when the piston is in the perfect position. So go back to the correct fuel and re set your timing. i had these same issues when i first got my car I did the same thing- and a big part of it was thst other than timing, and vac leaks, the car was running too lean- it ended up being the MPS was rebuilt but not retuned- once i had a AF meter i was able to fet the mps set correctly and then, no more pinging-

[mepstein]

Our cars run on regular fuel. Unless modified, they shouldn’t even need premium. Race gas is for race engines. Way too expensive to run on the street. Something is really wrong if that’s the solution.

[Rand]

When you change a part that affects timing and you then get pinging, it's pretty obvious that you need to readjust the timing.

The fuel octane subject has been beat to death around here. Look it up. Unless you have a high compression engine, running fuel with higher octane than regular is a waste of money and has the wrong burn rate.

[914_teener]

If the car did not ping with the stock distributor I would suspect the 123 unit is programmed more aggressively or just too much timing along of the curve.

Have you verified the advance with a timing light? A programmable timing light with RPM read out can help you determine where your at now through out the rpm range. The high octane will compensate for too much advance but at a high cost and inconvenience.

VP Racing Fuels on Western Ave and PCH sells race gas in any configuration you would want.

Have you verified fuel pressure? checking AFR would also be a good idea as you might be too lean which could lead to ping.

I am curious as was there ping before the 123 unit?

(IMG:style_emoticons/default/popcorn[1].gif)

Have you verified fuel pressure? checking AFR would also be a good idea as you might be too lean which could lead to ping.


(IMG:style_emoticons/default/agree.gif)

[mgphoto]

If the car did not ping with the stock distributor I would suspect the 123 unit is programmed more aggressively or just too much timing along of the curve.

Have you verified the advance with a timing light? A programmable timing light with RPM read out can help you determine where your at now through out the rpm range. The high octane will compensate for too much advance but at a high cost and inconvenience.

VP Racing Fuels on Western Ave and PCH sells race gas in any configuration you would want.

Have you verified fuel pressure? checking AFR would also be a good idea as you might be too lean which could lead to ping.

I am curious as was there ping before the 123 unit?

(IMG:style_emoticons/default/popcorn[1].gif)

Hey Pete,
the lid is coming along nicely, I just need some more sunny days.

The programmable timing light should be a good test, but that would be a six hand operation on a 914! I need to get enough friends together at one time to try it.

Fuel pressure is verified, but on the list of things to check again like compression.

Ping seemed to be and issue whenever the seasons changed. I would reduce the timing and feel the loss of power, until I switched the vacuum can to an adjustable one. I would loosen the lock nut and turn the adjustment screw in or out, increasing or decreasing the advance as needed.

What I am looking for in the 123 is a curve that might activate slightly later on the rpm scale or fewer degrees of advance, I believe the '74 D-Jet is 22* advance at 3000 rpm. This is where the TUNE + would be a great tool, if I could limit the max advance to 19* while keeping mid range at max advance.

[mgphoto]

I Rebuilt this dizzy when I built the motor about 15k miles ago.

[mgphoto]

Ok this engine is not stock.





J&E forged pistons, nickie cylinders, 9550 cam and valve train kit.
H rods, lightened and counterweighted crank, 8.3:1 compression ratio.
Lightened flywheel, built by me, D Jet tuned by me.