Neglected 951 redemption thread

[ColinGreene]

Compressor is like a year old. i ran it on the freeway later in the evening. It was probably around 70 degrees.
im in southern california so not super humid.

[Tom]

Compressor is like a year old. i ran it on the freeway later in the evening. It was probably around 70 degrees.
im in southern california so not super humid.

Hmmm... Something's not right there. R134a I assume? On a 70 degree say in So Cal, you should get into the 30's if not low into the 30's... Did you pay the shop to test the system at all, or just to fill it? Did they change the receiver drier? Leak-test it? Flush it? Pull a hard vacuum? There aren't many shops that do good work on these older a/c systems anymore. So much so, that I've given up here in Silicon Valley and do it all at home (other than having old refrigerant evacuated when needed). Between HF and Amazon, and Internet guidance, you can get pretty much everything you need to do the job right. More so than most jobs, getting cold air from the a/c is about all the little details, they all add up and can make the difference between 50 degree vent temps and 33 degree vent temps.

[ColinGreene]

No it is R12. I had a about 15 pounds on hand.
The compressor and drier were changed when i was getting the system running again.
they did no part changing.
when I removed the high pressure line from compressor to condenser, to when it was reinstalled was saturday to monday. I did put plugs into the system but it was more or less open for that time period.
These guys are supposedly R12 and R134 people.

They did pull a strong vac on it, however I did not time them.
At this point I am starting to suspect the system is actually overcharged.

At idle with both fans running with a ambient temp of 74 I had
28 psi low
280 high.

Given a little RPM around 2000
25 psi low
295 high.

Its on the list of things that make me go hmmmm
I may buy another drier just to have if they agree to come out and look at it.

[ColinGreene]

6 months later update.

The car has yet again quit running. Troubleshooting has not been condusive so far but its not a huge crisis.
I have tach bounce but no start. When checking the wave form on a Scope its not square but that could be my inexperience with using the scope.

I also was given a 2.5 block so i guess im building a 2.8
Question i had was with the Pauter rods on number 4 the rod bolt clears the girdle by about 28 thou, normally this feels tight to me but should I worry?
I can open it up some. everywhere else in the motor is about 40 thou.
Again not super freaked out but figured it cant hurt to ask.

[ColinGreene]

No one?

[Tom]

No one?

Sorry, I missed this the first time around. The raw waveforms for the speed and ref sensors are not square. They should look like this (ref on left, speed on right).

signals.jpg (21.04 KiB) Viewed 193 times

Tach bounce is usually a pretty good indication, but if you want to post what you are seeing on the scope, we can tell you if it looks right. The injector wires are a very similar source of no-start. If one connector shorts out inside (as they are known to do), none of the injectors fire. Rattle the harness as you crank and see if it comes to life. Does the boost gauge go to 1 when the ignition is on before cranking? If not, your DME/KLR might not be getting power due to a bad DME relay (which is probably the #1 cause of no starts on these cars). I'd also check for fuel and spark to see if that gives clues. If it cranks with tach bounce but with no sputtering, backfiring or other signs of life, other possibilities include a bad KLR (bypass to test), bad alarm system (bypass to test), bad ignition switch, and bad DME. If it does sputter or backfire, other otherwise 'try' to catch, then you are heading down a different path -- timing belt alignment, AFR issues from leaks/sensors, ignition component failures, etc.


As for the rod clearance, that's a pretty tight fit. I understand people have run those rods right out of the box, but I'd be inclined to get out the file myself. Have you asked Pauter?