Winter D jet tinkering, Are parts still available? Options

[robkammer]

The TTS is a temperature dependent sensor, it only provides ground to the AAR, completing its circuit to the AAR based on the ambient air temp just above the engine case. Super simple, just the we like it.

Brad Anders D-Jet pages have a new link, actually its now hosted directly on his personal server: https://pbanders.synology.me/914/

The previous site may remain accessible on rennlist for awhile, they don't keep them updated. Use the new link which has the most up to date information.

Thanks Jeff! This is confusing, the one lead to the AAR is it's 12 v power, isn't it? It seems to me that both, or all of the sensors, the AAR , cold start, etc all connect to/from the ECU. I'm thinking that with a meter I should be able to confirm continuity and voltage, if I can find a good diagram. I'll head back to Brads collection again. I have your diagram from the harnesses, and a Haynes, but neither detail these connections or routes. I've gotta believe theres a more comprehensive diagram out there after all these years.
Rob

[Superhawk996]

Haynes and factory service manual wiring diagrams have the info you need.

Anders site has all the theory of operation, parts table, and how to bench test various sensors.

[Superhawk996]

It seems to me that both, or all of the sensors, the AAR , cold start, etc all connect to/from the ECU.

You are mistaken - the AAR and the cold start valve are not input/output from the ECU.

Bench test them & then let us know how it goes.

[Superhawk996]

If you keep all information in one thread it will be easier to help you troubleshoot.

Here’s how to test the thermoswitch from the other thread:

The thermoswitch controls the cold start injector. Has nothing to do with the AAR.

The thermoswitch and cold start injector don’t even come into play unless vehicle and ambient temperatures are around 32F and below.

Review the Anders overview of d-jet operation and components.
https://pbanders.synology.me/914/djetfund.htm

Thermoswitch can be tested by placing in the freezer and then monitoring continuity with a DMM as it warms back to room temperature. It should be closed when it first comes out and then should go open as it warms towards ambient.

The AAR can be bench tested by simply powering it with 12v and observing the port (and or blowing air through it) to make sure the port closes after the AAR warms up.

The easiest way to test the cold start injector is to block its fuel supply line.

Given it is winter in Ohio, you’ve made no mention of whether you’re working in a heated shop or doing this work out doors in sub 32F weather where the cold start injector would be needed & used.

Given your description of how you’ve had to plug the decel valve ports, it would seem you probably have multiple issues with the system and previous band-aids going on that will need to be methodically worked through to get to what the actual issue is.

[robkammer]

Thanks Jeff, Wonki and Superhawk. I spent quite some time on the PBanders site, when he got to the Oscilloscope screen shots, I'm gone! He's at a way different level that this old wrencher. Part of my dilemma is that the car runs great, starts right up, once I get the temp gauge to move a little, it's all good!
My goal is to find the test specs for as many components as I can. Temps and resistance values, etc.. The decel valve is shot, It's been ok duct taped off for 3 years, but I know it's not right.
Our BB is a beauty, it's not my fave in our garage, but it's cool. I'm vacillating on taking it from a #2, to a #1 in anticipation of values coming back. To do that I need to pull the motor, fix some leaks, freshen up some things, detail the engine compartment, yada, yada.
At that point it becomes much easier to fiddle with all of the sensors and other EFI stuff. And some engine tin that was butchered when AC went in in 74.
I'm just getting back on my feet from a new knee. Tomorrow I'll be at my shop getting ready to refresh the suspension on our 986. Once that's done the lift will be open!
I really appreciate your input, and understanding
Rob

[rjames]

Cold start no problems, let it sit and idle for 5 minutes, ls no problem.
Once underway, as soon as I let off the pedal, it would want to stall. I was able to get through it by using the hand brake, but that's a pain.

Does this happen even after driving for 15+ minutes when the engine is fully warmed up?
Has the timing been checked and a valve adstment been done recently?

What is the idle RPMs when cold? If you let it idle for more than 5 minutes without driving it (engine fully warmed up and the AAR is closed), will it stall, or does it only stall after you start driving it?