Just strait up can't figure it out. $50 reward offered.

[theNomad]

Bad coil wire connection, shifting slightly under braking?

Probably just electrical harness though.

[Mike87]

Putting my vote on the timing curve. When it drops to idle from about 3K you are losing too much timing too fast. If you have another distributor, try swapping it in as a test.

[Dudeland]

3 hours ago, irdave said:

So not fuel?  Spark?  What about hard braking from speed but then lift before you stop to see if it starts back up?  (eg braking from 40 to 20mph...)

 

Everything has been recently installed; have you nut and bolted everything just to make sure it's still tight?

To be clear I pull up to a complete stop and then it will stall. The best way to put it  would be at maximum "G's" it will stall, or try. 

 

[Dudeland]

2 hours ago, Schnellvintage said:

Check your off throttle timing and throttle position the butterflies might be too far closed when coming off throttle.
Leaned out mixtures coming off throttle starving the holes.


Sent from my iPhone using Tapatalk

The manufacturer specs say to close the throttle plate until the IAC shows between 2 and 10% duty, mine is at 5 and steady at idle.  I have adjusted the speed of the IAC in terms of speed of adjustment,  as well as the idle position and nothing changes the stall. 

 

[Dudeland]

3 hours ago, irdave said:

So not fuel?  Spark?  What about hard braking from speed but then lift before you stop to see if it starts back up?  (eg braking from 40 to 20mph...)

 

Everything has been recently installed; have you nut and bolted everything just to make sure it's still tight?

Everything is tight, but I will double check.    

 

When I am driving at speed, it is just fine.  It only happens when coming to a complete stop. 

 

[Dudeland]

3 hours ago, mike said:

How new is your final fuel filter (the one closest to the injection)?  Could it be moving under hard braking and pinching the fuel line just enough to stall?

 

Is your injection Kugelfisher mechanical or a later EFI unit?  If the latter, how about the engine management system--or something electrical that controls the injectors--shifting enough to cause a momentary ground under hard braking?

 

mike

My injection is a Holley Sniper throttle body setup.  I have -6 an steel braided lines, and a canister type filter (looks like an oil filter).  It is also a water separator, and I am running 98 octane fuel.  

 

The unit is self-contained and has only one fuse, which is good,  and mounted using a riv-nut to the inner fender well. 

 

And fresh battery and newly rebuilt alternator. 

[Dudeland]

3 hours ago, irdave said:

So not fuel?  Spark?  What about hard braking from speed but then lift before you stop to see if it starts back up?  (eg braking from 40 to 20mph...)

 

Everything has been recently installed; have you nut and bolted everything just to make sure it's still tight?

The most recent thing to be bolted in the engine compartment is the EFI itself, and it has been there for a couple of months. 

 

I did replace a bad O2 sensor recently, 

[jimk]

If you logged a session and examined, it would tell the story.  All this other stuff is fishing.

[Dudeland]

2 hours ago, jimk said:

Haven't seen the answer to this.  Does it go lights out or show some funky reading?

 It always goes lean when I lift off, then comes down,  It sometimes overshoots rich when coming to a stop, like AFR of about 11 then settles around 12.5, or wherever I set it in the system.

 

I have played with different settings, but nothing seems to help.  I have no explanation as to why it overshoots.   If the Brake booster was leaking, would it cause these symptoms? 

 

Unmetered air entering the system?   It is either through brake booster or blows by the pistons. But why would it be variable when the car comes up to temperature?   I am burning no oil.   

 

 

[Dudeland]

2 hours ago, tzei said:

This i have found a hard way this to be a big no no. Somewhere contact is broken and it moves to no contact mode when you are breaking and harness moves. I’d start with tps wiring and then IAC wiring. IAC motor might be bad but my quess is you wiring harness is compromised.  Can you log data?

 

other things: have you done anything to engine harness? I’m intressed if any alterations is done to high current leads spark plug wires included (interference) or ground fixings.

The Injection system is self-contained, so it holds the IAC, TPS MAP all in one carb like unit, so no wiring to flop around.  No change in the wiring harness,  all shrunk wrapped and soldered with power going directly to the battery as per Holley instructions.  

 

I have a data log that I will send later tonight with pictures promised

[Dudeland]

2 hours ago, tzei said:

This i have found a hard way this to be a big no no. Somewhere contact is broken and it moves to no contact mode when you are breaking and harness moves. I’d start with tps wiring and then IAC wiring. IAC motor might be bad but my quess is you wiring harness is compromised.  Can you log data?

 

other things: have you done anything to engine harness? I’m intressed if any alterations is done to high current leads spark plug wires included (interference) or ground fixings.

I have a set of MSD 8.5 MM plug wires as per MSD recommendation with correct resistance wires. Plugs gapped to 32mm(i think, but I will double check.  They are new plugs as well.   Bosh standard ones that everyone uses (get the number off them tonight)

 

Grounds cleaned and in good shape.  I replaced the ground wire to the alternator when I replaced it about 5 months ago. 

 

 

[02Pilot]

If the AFR is going rich when you lift off and come to a stop, you've got some sort of fuel delivery issue. Too much fuel entering when at closed throttle and not at idle. Not saying it's the issue, but it's an issue. You shouldn't be going rich when the throttle is closed; the EFI should cut fuel when the TPS says the plates are at the idle position.

[Dudeland]

56 minutes ago, ray_ said:

That's not when the issue started, right?

 

You can clamp the booster vacuum line with VISE-GRIPS carefully, without damaging it. Or I can...

 

GL,

No, the problem seems to be there all the time.   I have a problem with the car overshooting the idle.  And for some reason (almost guaranteed to be related)  the car will come to a stop, idle great for about 3-4 seconds,  the idle will drop (sometimes severely, other times not)  and then recover. 

 

I feel like Etsy is in the lead with a bad brake booster.  What are the symptoms of a  bad brake booster? 

 

The three things I have narrowed it down to are 

 

1) Bad brake booster

2) Low compression

3) Fuel coming out of suspension in the intake and sloshing around while coming to idle. 

 

Ray, you are always a welcome contributor.   Maybe one day I will run into all of you at the Midwest.  

 

[Dudeland]

51 minutes ago, theNomad said:

Bad coil wire connection, shifting slightly under braking?

Probably just electrical harness though.

I zipped tied the hell out of everything.  There is only three wires to run the car.  

 

1) Power

2) ground

3) switched power. 

 

 

I am putting in a crank trigger as soon as I can get time to do it.   Just in case it is timing related. 

['76mintgrün'02]

7 minutes ago, Dudeland said:

They are new plugs as well.   Bosh standard ones that everyone uses

 

everyone uses NGK