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914World.com _ 914World Garage _ Why won't it stay running?
Posted by: nomedulla Nov 18 2013, 07:34 PM
EDIT
Posted by: r_towle Nov 18 2013, 07:43 PM
Valve are now to tight.
It happens, sorry, but do it again.
My 911 was the same way when I bought it.
It's important that you actually hear the tappets, it means they are set correctly.
Valves too tight will make the car run as you explained.
Posted by: nomedulla Nov 18 2013, 08:03 PM
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Posted by: 76-914 Nov 18 2013, 08:22 PM
Do it before you drive it again. Better too loose than tight. Too loose won't harm anything but your ego. Too tight makes your check book open.
Posted by: gothspeed Nov 18 2013, 08:41 PM
Do it before you drive it again. Better too loose than tight. Too loose won't harm anything but your ego. Too tight makes your check book open.
+1 ....
Posted by: nomedulla Nov 19 2013, 04:17 PM
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Posted by: boxsterfan Nov 19 2013, 04:59 PM
Do it before you drive it again. Better too loose than tight. Too loose won't harm anything but your ego. Too tight makes your check book open.
+1 ....
OK, I have readjusted the rocker arms again, checked the timing, etc., and it still will not idle without "butterflying" the throttle.
What next?
I have pulled the plugs, they are clean and gapped. Checked all the hoses and connections, again. Should I test the AAR/Throttlebody readings? Is there anything else that would affect the air/fuel/idle ratio? It runs well when accelerated, but will not stay consistent after a few moments at higher RPM.
I have a Petronix unit. I pulled the distributor and checked the gap from the pickup to the magnet...it is at .003, as the manufacturer recommends.
I am not Mr Goodwrench, but I have been tinkering with VW/Porsche 914s since my teenage years... 69VW being my first car, 74 2.0 my second.
Is this when engine is cold? Could be stuck closed AAR. My AAR had the exact opposite at cold start....idles up around 1800 until then warmed up and then goes to 3000 RPM because the AAR doesn't close (stuck open). I've got a new refurb one to install, but my short term workaround every morning has been to get out and plug the input to the aair vac line (after which idle immiediately drops to 950). Voila!!
Posted by: nomedulla Nov 19 2013, 05:43 PM
EDIT
Posted by: Jeffs9146 Nov 19 2013, 05:46 PM
Are you adjusting the valves when the motor is cold or warm?
Posted by: nomedulla Nov 19 2013, 06:05 PM
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Posted by: Cap'n Krusty Nov 19 2013, 07:25 PM
Have you read my tutorial in the classic threads?
The Cap'n
Posted by: Jeffs9146 Nov 19 2013, 08:12 PM
Are you adjusting the valves when the motor is cold or warm?
...without question when they are cold.
Just throwing it out there!!
Posted by: nomedulla Nov 19 2013, 08:33 PM
Have you read my tutorial in the classic threads?
The Cap'n
Yes Sir... Will be reference material
Posted by: nomedulla Nov 19 2013, 08:35 PM
Are you adjusting the valves when the motor is cold or warm?
...without question when they are cold.
Just throwing it out there!!No worries, I know sometimes the most obvious is something that may be overlooked. Thanks for taking time to review my thread and offer input.
Posted by: turk22 Nov 19 2013, 08:45 PM
did you do anything else in conjunction with the valve adjustment? like new plugs, oil change etc. ?
It may be something that came loose while you were in the engine compartment.
Posted by: r_towle Nov 19 2013, 08:50 PM
Do you have the knob on top of the ECU to adjust your idle mixture?
This happens only when cold? Check your CHT wiring, make sure it tight and you did not damage it while doing the valves etc....it happens.
Umm,
Plugs, all of the FI plugs, pull them and reset them.
Can you affect the idle by setting the idle air bypass screw?
Does the do anything?
If not, there are other things to look at.
If that works, it's most likely AAR...
Posted by: nomedulla Nov 20 2013, 07:20 AM
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Posted by: nomedulla Nov 20 2013, 07:23 AM
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Posted by: r_towle Nov 20 2013, 08:11 AM
well, the sudden change in morning/ overnight temps may have affected what you are dealing with.
Pull the AAR out.
Ground it at the body.
Add power to the red lead.
Does it open all the way?
Does it close all the way?
Even before that...
Two fuses on the engine compartment relay...still good?
I dont recall the wiring diagram with respect to the Temp Sensor and the AAR, but they are right next to each other in the wiring loom....
Did you jostle that AAR connection in some way?
Rich
Posted by: r_towle Nov 20 2013, 08:15 AM
I always do these type of triage things with a few assumptions.
I did something wrong.,..
The simplest thing is typically the issue.
So, what did you touch, back track.
If you pulled out the spade to solder...what else did you disturb in the process.
Its not like there is plenty of slack in that harness.
You would have disturbed (possibly)
all the Injector grounds (passenger side, under the plenum, top case bolt near rear)
AAR
Distributor EFI trigger points
Coil wiring
I think that is all that is over there....but you may want to just follow the wiring loom for the EFI and check every connection, reseat all of them, etc.
Posted by: The Cabinetmaker Nov 20 2013, 02:06 PM
The thermo tine switch has nothing to do with the AAR. It lets the ecu "see" ambient temp so it can open the cold start valve. The aar opens and closes via a bimetallic spring that reacts to temp. Even with no power to the aar it will eventually close anyway by the engine heat, assuming the aar works properly.
Posted by: Rand Nov 20 2013, 02:09 PM
Did you say it ran fine before you adjusted the valves?
Posted by: The Cabinetmaker Nov 20 2013, 02:14 PM
Did you say it ran fine before you adjusted the valves?
Yes he did, and therein. I think, lies the problem. Did the same thing on my first vlave adjust many years ago.
Posted by: Rand Nov 20 2013, 02:19 PM
Have to wonder how this spins so far away before addressing that.
Maybe something went awry there?
Posted by: r_towle Nov 20 2013, 02:26 PM
Have to wonder how this spins so far away before addressing that.
Maybe something went awry there?
did you read the thread from the beginning?
Just curious...
Posted by: The Cabinetmaker Nov 20 2013, 02:29 PM
Rich addressed that on the second post of the thread, and 76-914 two posts later. He says he readjusted them, but were they done properly???
Posted by: Rand Nov 20 2013, 02:38 PM
Same question still stands. It ran fine before. If there was an error in valve adjust process, it remains no matter how many times repeated.
If not, no prob. Just asking. 
Posted by: nomedulla Nov 20 2013, 06:04 PM
EDIT
Posted by: r_towle Nov 20 2013, 06:12 PM
From what I have seen, Petronix are binary...work or no work....no middle ground.
So, your timing might be wierd now....take another look at how you mounted the plates, correct orientation no screws binding the motion...that can happen with the Petronix unit...the mounting screw might bind he advance plates...
Again, go look at what YOU did first, before you chase everything else.
Rich
Posted by: Java2570 Nov 20 2013, 06:48 PM
When I tried to solder my points plate ground wire, it quickly vibrated loose and caused the car to die.
However, then it wouldn't restart....it didn't act like what you are seeing. I ended up replacing the points plate in mine and that fixed my issue.
Could you have possibly moved your timing?
Posted by: nomedulla Jan 3 2015, 08:04 PM
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Posted by: messix Jan 3 2015, 08:29 PM
"Accelerator response still does not coincide with motor response
Revving motor, RPM gauge does not appear to coincide with sound of RPM being generated"
this concerns me.
does the tach "lag" behind the throttle opening?
does the engine lag behind throttle?
have you checked the tach wire connections?
there are air bypass adjustments at the throttle body. have you tried to adjust it there?
Posted by: nomedulla Jan 3 2015, 08:33 PM
EDIT
Posted by: r_towle Jan 3 2015, 08:37 PM
Do you have another tach to test?
Posted by: nomedulla Jan 4 2015, 05:03 AM
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Posted by: nomedulla Jan 4 2015, 04:12 PM
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Posted by: r_towle Jan 4 2015, 04:20 PM
Try removing the hoses from the cold start injector and putting a solid piece of tubing, or one long hose in its place so no fuel touches the cold start injector.
Sometimes the die open and make the car run too rich, but may also make the pressure go down once you stop the car...
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