CIS test complete, please evaluate:)

[Steve F]

Finally had a chance to do the pressure test.....From the CIS for dummies thread (thanks by the way tirwin!)

"Was" running great , then the backfiring began...has Pop off but still think there are vac leaks which is the next step, but wanted get my bearings on the fuel pressure test first.

1981 Targa SC


1. Year of engine: 1979 long block with 1981 CIS plus O2 sensor

2. US or RoW (Rest of World): US engine #*65913883*

3. WUR model number: 0 438 140 045

4. Ambient temperature at time of test (in degrees C): about 18c or 64 degrees ish

5. WUR Resistance (in Ohms): this test done at 24c or 75 degrees ish yesterday=24.7-24.9 ohms

6. System Pressure (in bars): 68 psi 4.6-4.7 bar

7. Cold Control Pressure (in bars): 29 psi 1.9 bar

8. Warm Control Pressure (in bars): 40 psi 2.7 bar

9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): 1 min 40 psi 2.7 bar 2min= 45 psi 3.1 bar 3 min= 45 psi 3.1 bar

10. Residual Pressure @ 5 min (in bars): 31 psi 2.1 bar

11. Residual Pressure @ 15 min (in bars):27 psi 1.8 bar

12. Residual Pressure @ 30 min (in bars):24 psi 1.6 bar

13. Residual Pressure @ 60 min (in bars): 23 psi 1.5 bar

Thanks for any and all comments!

Best,Steve

[Moozak]

Hi Steve, it looks like your system pressure is good, cold control is in spec, but on the low side, and I'm a little confused by your warm pressure reading being 2.7 bar, but in your time delta readings after 3 min reading is 3.1 bar? Residual looks strong.

Cheers,

Jon

[Steve F]

Thanks for your input Jon,

First time for me doing this test, I hope I followed the directions correctly. As mentioned before, there was never any issue other than a little reluctant from cold, but always leveled out nicely had a good idle and ran great. No hot start issues either. That all tanked overnight with one start Going to try to hunt down vac leaks tomorrow.

Cheers,Steve

[boyt911sc]

Steve,

Was the engine running when you did the fuel pressure test? Or just the FP running? Since you have a lambda system from an '81, you are using a WUR-045 that is not designed for this particular type of CIS. There are some minor differences in your fuel pressure data that caught my attention. Since you did not specify if the test was done with a running engine or not, it is quite difficult to make a good assessment. What is the FD (fuel distributor ID number). FD-031 or -077 or something else? Keep us posted.

Tony

[Steve F]

Tony, thanks for your reply.

No, engine not running just FP running, haven't started it since the back firing episode. FD is 0 438 100 077
266 813 141

AAV 0280160-02

Dist. 0237306001
050 PGFU6


Yes, I think I should have a 090 Wur, but that is what's there and was to my knowledge for the last 6 years.

Anything else I can I supply please just ask!


Thanks again!

[boyt911sc]

Originally Posted by Steve F

Tony, thanks for your reply.

No, engine not running just FP running, haven't started it since the back firing episode. FD is 0 438 100 077
266 813 141

AAV 0280160-02

Dist. 0237306001
050 PGFU6


Yes, I think I should have a 090 Wur, but that is what's there and was to my knowledge for the last 6 years.

Anything else I can I supply please just ask!


Thanks again!

,



Steve,

Right now, looking at the fuel pressures you obtained and using WUR-045 should not prevent your engine from starting provided you don't have significant unmetered air going into the system. Test and confirm the absence of air leak/s. You could fine tune it later once the engine is running.

If I were doing the troubleshooting, I would simply find a good working WUR-090 to replace the WUR-045. It would be a challenge to make the WUR-045 perform like a WUR-090. Wish you the best.

Tony

[Steve F]

Thank you very much Tony!
I will first at least look for any obvious leaks, air box, connections, so forth and then get the proper Wur designed for this system. Thanks again and I always look forward to your replies in threads , always a informative response.

Cheers Sir!