Need help interpreting CIS test results

[997at]

I just finished doing the pressure checks on my CIS and would really appreciate if those in the know could help me interpret the results:
1982 SC
Type 090 WUR
Resistance 8 ohms at 22 deg
System pressure 4.8 bar at 17 deg (right in middle of Bentley range)
Cold control pressure 2.1 bar at 17 deg (right in middle of Bentley range)
Warm control pressure 3.8 bar at 17 deg, reached at 1min 15 sec (upper end of Bentley range, and fast time to max pressure)
Residual pressure:
5 min, 2.1 bar
15 min, 1.8 bar
30 min, 1.7 bar
60 min, 1.6 bar

To me it seems like my pressures are okay, but the resistance is too low and the warm up too fast meaning it leans out too quickly?
Can this be corrected, is my WUR toast?

Thanks for any advice/support.

[pmax]

My apologies for speaking out of turn, no expert here !

Yes, the resistance is low. I believe it should be in the 20s or above.
How is the car running ?

[997at]

Unfortunately the car quit running and won't start which is the reason I'm doing the tests. I know I have some huge vacuum leaks that I'm going to address by dropping the engine and checking everything, but I wanted to troubleshoot from scratch verifying spark (done), fuel (where I am now), and then vacuum/air (engine drop).

[Bob Kontak]

Originally Posted by 997at

To me it seems like my pressures are okay, but the resistance is too low and the warm up too fast meaning it leans out too quickly?
Can this be corrected, is my WUR toast?

Your resistance is low. I don't see this as a show stopper right now.

Your pressure numbers are in tolerance.

I remember having a discussion with Tony about the time it takes to get to WCP. I was thinking it had to be a couple minutes. Tony responded with the later US CIS models "warm up" very fast because of the need to get it to full lean, pronto, for EPA compliance. Maybe only 90 seconds? But I was surprised at the brief duration.

That said, your's gets to lean really fast and you are at the very lean end of the WCP tolerance once you are there. Your engine is still pretty cold. A richer mixture would be sweet for another minute but that's not the case, AND you have massive air leaks.

Your engine is starving for fuel after one minute fifteen seconds because of the air leaks.

You can't start it, though. Even if too lean, there is so much fuel fogged into the engine with the cold start valve your car should start then die if I am in the ballpark. Is it doing that?

[997at]

Originally Posted by Bob Kontak

Your resistance is low. I don't see this as a show stopper right now.

Your pressure numbers are in tolerance.

I remember having a discussion with Tony about the time it takes to get to WCP. I was thinking it had to be a couple minutes. Tony responded with the later US CIS models "warm up" very fast because of the need to get it to full lean, pronto, for EPA compliance. Maybe only 90 seconds? But I was surprised at the brief duration.

That said, your's gets to lean really fast and you are at the very lean end of the WCP tolerance once you are there. Your engine is still pretty cold. A richer mixture would be sweet for another minute but that's not the case, AND you have massive air leaks.

Your engine is starving for fuel after one minute fifteen seconds because of the air leaks.

You can't start it, though. Even if too lean, there is so much fuel fogged into the engine with the cold start valve your car should start then die if I am in the ballpark. Is it doing that?

Bob, thanks for the thoughts. I guess I can live with the low resistance for now. When the car was running I noticed that it really took 5 min before it was happy.
I agree with you that it should fire up for a few seconds before dying but that's not the case. If I crank for 10 seconds or so I get a few fart like backfires from the intake side at best. It could be that my CSV is crapped out too?

[Bob Kontak]

Originally Posted by 997at

It could be that my CSV is crapped out too?

These cars start well even if effed up. How does it do when stone cold?

[brentrussell]

I think it won't start because of the "Huge vacuum leaks", no point waiting if you know they are there. Partial engine drop or removal is a lot easier than removing while bolted up but not impossible.

[Bob Kontak]

Originally Posted by brentrussell

I think it won't start because of the "Huge vacuum leaks", no point waiting if you know they are there. Partial engine drop or removal is a lot easier than removing while bolted up but not impossible.

I hear you but if cold start valve is working it should start. Initially.

The fog of fuel can override vacuum leaks, to a fault, sometimes. I forgot to reattach the Aux Air regulator hose to the snoot once. Started and then sent a sonic boom through the neighborhood via the intake when it died. What did I do? I started it again and the same thing happened.

[997at]

Originally Posted by brentrussell

I think it won't start because of the "Huge vacuum leaks", no point waiting if you know they are there. Partial engine drop or removal is a lot easier than removing while bolted up but not impossible.

I'm thinking (and hoping) that this is the case. I feel like I'm at the point where I can drop the engine and fix leaks. I plan to do a full drop. Can the CSV be tested some way with the engine out?

[boyt911sc]

Originally Posted by 997at

I just finished doing the pressure checks on my CIS and would really appreciate if those in the know could help me interpret the results:
1982 SC
Type 090 WUR
Resistance 8 ohms at 22 deg
System pressure 4.8 bar at 17 deg (right in middle of Bentley range)
Cold control pressure 2.1 bar at 17 deg (right in middle of Bentley range)
Warm control pressure 3.8 bar at 17 deg, reached at 1min 15 sec (upper end of Bentley range, and fast time to max pressure)
Residual pressure:
5 min, 2.1 bar
15 min, 1.8 bar
30 min, 1.7 bar
60 min, 1.6 bar

To me it seems like my pressures are okay, but the resistance is too low and the warm up too fast meaning it leans out too quickly?
Can this be corrected, is my WUR toast?

Thanks for any advice/support.

The WUR is out of spec. as far as the heater resistance is concern. But this should not prevent the engine from running. The low heater resistance will cause you an erractic cold idle. What you need to test are:
a). CSV operation during start.
b). Ignition signal.
c). Unmetered air going into the system.
d). Test and verify that no fuel is prematurely delivered by the injectors while the FP is running. And all injectors have good spray patterns.

The above test could be done with the engine installed or removed. I will place my bet on "unmetered air".

Tony

[997at]

Originally Posted by boyt911sc

The WUR is out of spec. as far as the heater resistance is concern. But this should not prevent the engine from running. The low heater resistance will cause you an erractic cold idle. What you need to test are:
a). CSV operation during start.
b). Ignition signal.
c). Unmetered air going into the system.
d). Test and verify that no fuel is prematurely delivered by the injectors while the FP is running. And all injectors have good spray patterns.

The above test could be done with the engine installed or removed. I will place my bet on "unmetered air".

Tony

Thanks for the input Tony. A couple of questions:
I verified spark via an inductive timing light and a spare spark plug - is this considered good enough of a test?
Are you saying that I can perform tests a and d with the engine removed? This would be my preference as I have to remove it to fix all potential leaks anyway.
I should let you know that my leaks were big enough to where completely turning down the idle set screw only got me down to 950rpm, and taking off the oil filler cap made no difference at all. I had also adjusted the mixture set screw super rich to compensate for the unmetered air.

Also, regarding the WUR, should I just leave it alone at this point. I assume a replacement WUR would be needed to fix the resistance issue?

[gazzerr]

Originally Posted by Bob Kontak

I hear you but if cold start valve is working it should start. Initially.

The fog of fuel can override vacuum leaks, to a fault, sometimes. I forgot to reattach the Aux Air regulator hose to the snoot once. Started and then sent a sonic boom through the neighborhood via the intake when it died. What did I do? I started it again and the same thing happened.

Ha ha. And I bet you did it the second time just for fun. .

997at I had a huge hole in my CIS hat that rides above the air flow meter. I suspect your airbox probably has a really big leak and that's why it won't start.

[T77911S]

pull a vacuum on the hose that goes to the brake booster, that will test the hose and booster for air leaks. highly overlooked cause of air leaks