Need help getting 1991 back in operation

[dmaclennan]

Originally Posted by XfireZ51

Don,

I would go w Hans' suggestion and look at the chip. All LT-5 MY have 2 calibrations for them. If urs is AXFK, then its the original calibration and GM issued a second one which is the BFXB calibration. So I would make sure that u have the revised cal to begin w.

OK. Did not know that there were 2 calibrations from GM. Do you know what the BFXB changed? It's an original CA car and passed smog through 2001 at least, possibly as late as 2009. I'll check on the chip and get back.

Thanks,
Don

[Ccmano]

Originally Posted by dmaclennan

OK. Did not know that there were 2 calibrations from GM. Do you know what the BFXB changed? It's an original CA car and passed smog through 2001 at least, possibly as late as 2009. I'll check on the chip and get back.

Thanks,
Don

Im curious, do you have any of the old smog test results sheets? It would be interesting to see the old specs the state used compared to what they expect to now.

If 2009 was the last time, I assume you got all the old gasoline out and put all fresh gas in. I also assume, since you previously got it smogged there, you had it tested with the power key off, even removed, so that secondaries don’t operate.
H

[dmaclennan]

Originally Posted by Ccmano

Im curious, do you have any of the old smog test results sheets? It would be interesting to see the old specs the state used compared to what they expect to now.

If 2009 was the last time, I assume you got all the old gasoline out and put all fresh gas in. I also assume, since you previously got it smogged there, you had it tested with the power key off, even removed, so that secondaries don’t operate.
H

Went looking but can't find any old smog tests. Had a look at one for our 2001 XJR and almost all the requirements for it are lower than required for the ZR-1.

Can't remember about the fuel but I think I put the 5 gal or so that was pumped from the tank in my Denali - may have put it back in the ZR-1. Filled the tank completely before the first smog - that was before I pulled the plenum and she wasn't running very well. Only failed the Nitrous Oxides test on the first smog. HC and CO were well under the limits. After fixing the vacuum leak and installing new injectors I put another 10 gallons in before the second test. That's where the HC fails as well as NO. Both CO and HC emissions jumped way up after the plenum pull and new injectors. NO came down a bit. Even though CO jumped up it is still half the max.

Cheers,
Don

[Jagdpanzer]

Imagine it will be tough to get through current Cal emissions test without EGR. That was my experience in Northern VA which has the same limit values

[dmaclennan]

Originally Posted by XfireZ51

Don,

I would go w Hans' suggestion and look at the chip. All LT-5 MY have 2 calibrations for them. If urs is AXFK, then its the original calibration and GM issued a second one which is the BFXB calibration. So I would make sure that u have the revised cal to begin w.

Mine is the AXFK chip. Guess I'll need to add a new chip to the repair list. Anyone know what the second chip changed?

As an update, I checked the ignition today - spark seems good on all 8. Also checked the A.I.R system using the tech 1. I can hear the pump come on for a few seconds and the O2 sensors drop to 0 mV on the left and 18 mV on the right. Seems to be working OK.

When doing the spark check, I did notice a hissing sound near the rear of the engine that lasted for 10 sec or so after shutting down. Something leaking? Is this normal?

Will investigate further.

Cheers,
Don

[Ccmano]

What injectors did you install? I think I asked before but are you smog testing with the power key off or out of the car?
H

[dmaclennan]

Originally Posted by Ccmano

What injectors did you install? I think I asked before but are you smog testing with the power key off or out of the car?
H

Bought the injectors from Gerry's Gaskets. FIC.

Key was off for smog test - I think it was in the ash tray.

Cheers,
Don

[dmaclennan]

Got advice from Marc and I'm in the process of changing the O2 sensors. Left one was easy. Got the right one out easily but i am having difficulty getting the electrical connector installed. Another older thread suggests removing the k-frame brace. There are 4 bolts attaching the brace to the frame and a nut that appears to be attached to the engine mount. Does this nut get removed too?

Any ideas on how to get the connector re-connected?

Planning a long run with CRC 05063 after the O2 sensor is re-attached then another smog.

Cheers,
Don

[tpepmeie]

Bfxb was not specifically different for emissions. That likely won’t make a difference for you. Save the money.


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[Ccmano]

Yes, the nut has to come off. While it is the nut for the engine mount, it and the “K” member do not support the engine. After you have the O2 sensors in take it for a long hard drive to get the cats good and hot. Its likely the cats got a bit contaminated from that old gas, long inactivity and frequent startups without really driving it. When I still lived I CA I found that a few good full throttle runs to redline immediately before taking to the smog station brought the numbers down somewhat.
H