Ok so my new 6.0L V12 XJS just failed it's CA smog test due to high hydrocarbon levels -

max at 15mph is 78 and I scored 115
max at 25mph is 44 and I scored 49

any advice as to my next step ? - is there a reliable fix the home mechanic can do to get it to pass the test next time arround -

the car has 75k miles and had a full service incl. plugs, fiters, fluids,fuel filter,at 72k miles back in January.

It's previous smog test was done last October and it passed with no problems -

any advice as what to do and where to start would be much appreciated -

cheers all

James

1995 XJS 6L V12 CONV.
1974 Jensen Healey #18149

Submitted by silver007@shaw.ca on Fri, 08/05/2005 - 01:08

Hey James,
there are lots of things you could do, change the oil and put in some goog full synthetic 5w50 if you can get it or at least 20w50 full synthetic, make sure tyres are well pumped up, get a special pre test additive such as GTP ( guarenteed to pass )available at pep boys or such, do as per instructions only. clean air filters, my sons just whizzed through our test in BC, and it is tough, good luck....... Art Dickenson.
1983 XJS GT \"Silver\""

Submitted by SE21-33540J on Thu, 08/04/2005 - 22:17

James,

I may be off track on this, but did they adjust the Rich/Lean mixture setting on the side of the ECU? My car has an adjustment on the side of the ECU, put there as a modification by AJ6 Engineering. My mechanic said that Jaguar put the same thing on the V12's. Maybe you need to lean it out before the testing if this is the case.

Jerry
1986 XJ-SC 3.6 / 5 Speed
2000 S-type 3.0

Submitted by james_brinkley… on Thu, 08/04/2005 - 17:28

Full test results are as follows:

/ %CO2 / %O2 / HC (ppm) / CO(%) /
Test / RPM / MEAS / MEAS / MAX / AVE / MEAS/ MAX / AVE/ MEAS/
15mph/ 1517 / 14.6 / 0.1 / 78 / 21 / 115 /0.45 /0.06/ 0.15 /
25mph/ 1488 / 14.6 / 0.0 / 44 / 13 / 49 /0.41 /0.05/ 0.05 /

NO (ppm)
Test / MAX / AVE / MEAS
15mph / 676 / 150 / 371
25mph / 676 / 136 / 153

Submitted by james_brinkley… on Thu, 08/04/2005 - 17:25

follow up - wires are also new - Disrtibutor was not changed.
I had a 15 min arround town drive before the test so the engine was warm.

Full test results are as follows:

/ %CO2 / %O2 / HC (ppm) / CO(%) /
Test / RPM / MEAS/ MEAS / MAX / AVE / MEAS/ MAX/ AVE/ MEAS/
15mph/ 1517 / 14.6/ 0.1 / 78 / 21 / 115 /0.45/0.06/ 0.15/
25mph/ 1488 / 14.6/ 0.0 / 44 / 13 / 49 /0.41/0.05/ 0.05/

NO (ppm)
Test / MAX / AVE / MEAS
15mph / 676 / 150 / 371
25mph / 676 / 136 / 153