I didn't have time to swap hose positions on TTV, nor remove/test it, but I did remove the heater blower to allow greater visual inspection of the plumbing.

If it's supposed to look like this...

http://forums.pelicanparts.com/uploa...1536285182.jpg

... it doesn't.

As previously discussed, the vacuum hose from my WUR goes to the middle port of the TTV. The hose from the side port of the TTV then goes to a "T" fitted on to the Vacuum Limiter. The hose on the other side of the "T" goes into the throttle body(?) on the back side (not the front side as in the schematic).

http://forums.pelicanparts.com/uploa...1536286696.jpg

Here's the port (circled) that the split from the TTV is supposed to go into per schematic

http://forums.pelicanparts.com/uploa...1536287367.jpg

Here's a vid:

https://youtu.be/R1d5OJ-_nek

Does anyone have photos of a dropped '79 USA engine showing CIS intact?

Thanks,
Jason

Don't follow that parts diagram. Jim William's excellent CIS primer has the correct diagram of the vacuum connection.
The hose goes to the front (of the car) side of the TB and that's what your video shows which is correct.

Stay the course with either of the alternatives SkiVT has detailed earlier to isolate the TTV as the possible culprit here.

Cool, your video might be the first in this forum showing how the TTV is supposed to operated from the factory. Those other tests in your link earlier were all done with decades old parts.

My line from the decel valve to TB is as in your video. You could just attach your vacuum pump to the TTV ports while in the car. Other threads have vacuum holding until the temp hits high 80's so it may be cool enough in your garage. My belief is your TTV holds vacuum as you said when the hoses are correctly connected, the startup idle got worse. If it wasnt holding vacuum, idle would be the same as the 2.7 ccp pressure you observed because vacuum is happening immedietly. My guess again is the afr has been tuned for startup at 2.7 CCP. When you correct the hoses and vacuum is held off, your CCP is 2.1 which will then drop/richen your afr, which ends up being too rich to make happy idle.

the vacuum port from the TTV (WUR) goes to a port that is BELOW the throttle plate, IE manifold vacuum.
you vac on the WUR all the time except WOT. it will lose vac when you accelerate momentarily. helps with acceleration.

Will do so, have time this w/end.

Thanks,
Jason

... it looks a bit different now ...


http://forums.pelicanparts.com/uploa...1536339442.JPG
http://forums.pelicanparts.com/uploa...1536339543.jpg

A pic of what I used, should anyone have interest :


http://forums.pelicanparts.com/uploa...1536414777.jpg

Thanks,
Jason

Before doing that, measure the fuel pressures engine running with the TTV correctly connected. If the engine dies, pull down (assuming it's too rich) the sensor plate slightly.

Thanks pmax.

Reversed the hoses to the TTV, so that the Decel Valve hose went into the middle port, and the WUR hose into the outside port.

Ambient temp: 73 F

Hooked up pressure gauge, vacated air from the gauge hoses, and fired her up. Frankly I didn't expect it to hold idle, as previously it hadn't, but it did this time.

As you will see in the video below, initial pressure at start up was about 3.0 Bar. After about 15 seconds (TTV opens up?) the pressure starts to increase, although not rapidly as SkiVT's had in his video. Ultimately it reaches about 3.8 Bar.

At about 48 secs, I start to play with the sensor plate; pulling down slightly loses idle. pushing up slightly does the same, as you will hear. I tried it a few times, as you will see.

At about the 4:41 mark, you will see me remove the vac hose from the WUR - FP drops about .3 Bar. Then I reconnect it. Back it goes to 3.8 Bar.

What you don't see is that the idle has dropped to about 800 RPM by the end of the vid. So subsequently I adjusted to about 950.

https://youtu.be/PCa6j_ABuzo

Warm start-up was smooth.

Thoughts?

Thanks, Jason

Jason

I think the TTV is open, sending vacuum to the WUR, throughout your test today. The gradual rise in pressure is due to the WUR heating up, not the TTV opening up. Looks like it's running fine this time with the TTV correctly connected. Unfortunately, that doesn't help when the previous stall problem can't be reproduced.

I would check the AAR next. When the engine's cold, disconnect the hose (part metal on the "outside") to the AAR, use a mirror and see if it's partly open.

http://forums.pelicanparts.com/uploa...1536461147.jpg

Something seems amiss. Your pressures in your first post have 2.1ccp then increasing over time as they should. Now the video at startup has ccp at 3.0 with same ambient temp? Is this a cold start video?

Checked - it’s open (btw, I just stuck my phone there and snapped a pic):

http://forums.pelicanparts.com/uploa...1536494652.jpg

2.1 was initial cold pressure engine not running/WUR power disconnected. 3.0 was cold start up (engine running). Maybe my terminology is inaccurate?)

When the TTV is working, your ccp should hold at 2 for 15 to 25 seconds, then rise like it did when you plugged the electical to the wur in your no engine running tests. The no engine running test simulates power coming to the wur when you start the engine. Jumping immediately to 3.0 seems strange, particulalry if vacuum is held off by TTV.

OK, so we are getting some extra air on startup.

Here's my next suggestion.

Run the same fuel pressure tests under the same conditions as in your original post, no engine running to verify the FP is 2.1 as before but this time, also monitor the AAR opening as well during the test. The AAR should close completely after a few minutes.

...

However, as SkiVT says above, the TTV is supposed to be open during startup in your latest video. I would defer to that given there is no one else who has tested a new TTV.

I checked the AAR - did I do this correctly?; I had the ignition at "on", engine not running. Left it on for a good 8 mins or so. AAR did not close.

Thanks,
Jason

AAR: I believe the AAR (and WUR and TTV) only gets power with the key in the starting position and when engine running. Just turning the key to run does not energize those parts. I think if you energize it like you did with the TTV, that should be a better test. I did that after taking it out of the car. Put the AAR in the freezer to see it fully open (or not) and then apply power to watch it close.

The AAR shares the same 12V with the WUR, so if the WUR is heating up with the FP relay bypassed as described and the AAR is not closing, the latter's probably busted. Try squirting some WD40 and see if it frees up, can't hurt.

The WUR also appears inconsistent given the lower temp should result in a lower CCP not higher as you reported.