Deaded Idle Surge?

[GOLDCYLON]

Originally Posted by Sgreg

This should have been a recall and not just a Service Bulletin ! Hard to find an owner of a 90 or 91 Z with the original Memcal that hasn't had high idle problems and hard hot cranking.

I agree Greg but at this point with the expection of the 163 mile 90s showing up latley most have replaced the chip already. But I concur it should have been a safety recall. Something tells me if the car was automatic it would have been due to lurching events.

[tomtom72]

Just an observation, the date on the TSB is 2/94. I'll bet there had to have been complaints or something. It seems to have taken quite awhile for the software guys to figure out a soloution; or not too many 90 owners were driving their cars and complaining?

My 90 had 7400 on it and still had the OEM PROM in it, that was my first "Mod".....I should have bought two as cheap as they were from GM. Sheeeish, I'm soooo dumb sometimes. They were like $34.00 each! Now I have to give it up to have Mr. Haibeck redo it when I get my headers installed as he said that is the better of the two programs to write to.

[Jarek5_7]

can anyone see if its a updated bin? what xfire posted?

two days ago when finally weather let me drove the Z, I took a spin. the car runs strong and full power comes on and really pulls great. after cold start rpms go down to reasonable cold engine rpms but after short drive it idles ok but after engine gets warm it idles very high. it makes me MAD, I really think I have no vacuum leak , I checnged injectors, plenum gaskets, tb gaskets, checked vac hooses, put in new pcv valves, new check valves under plenum etc.

while slowing down to stop on neutral it idles around 2k rpms !! and hold it for a while at stop and then starts after 2 sec to drops by steps but not to desired level.

this is the most annoying thing in the car, I will be so happy when I fix it....

[vettn71]

Daryll

The car has never backfired; has always run as smooth as a baby's behind. I know it has the original plugs (15xxx miles), so they probably need to be changed out, but that's a different issue. I'll have to get under there and check all those hoses. Nothings been off, nothing has been changed. ?????

[XfireZ51]

Originally Posted by Jarek5_7

can anyone see if its a updated bin? what xfire posted?

two days ago when finally weather let me drove the Z, I took a spin. the car runs strong and full power comes on and really pulls great. after cold start rpms go down to reasonable cold engine rpms but after short drive it idles ok but after engine gets warm it idles very high. it makes me MAD, I really think I have no vacuum leak , I checnged injectors, plenum gaskets, tb gaskets, checked vac hooses, put in new pcv valves, new check valves under plenum etc.

while slowing down to stop on neutral it idles around 2k rpms !! and hold it for a while at stop and then starts after 2 sec to drops by steps but not to desired level.

this is the most annoying thing in the car, I will be so happy when I fix it....

Jarek,

The bin I posted is an updated one. It uses the AFA Mask ID which is an update to the original AF Mask ID. GM added some code to all the ZR Masks at one point and came out with "A" versions of them. The BFXB won't work well with the AF Mask. I also compared the BFXB v BRXB bin.
They are nearly identical with slight changes in Injector Bias v Battery Volts, and in some of the Knock calibrations. Both also have slightly lower IAC steps v Coolant than the stock bin which is probably part of the fix they incorporated.
You can burn these bins and install, or you could take stock bin and make mods to drop the idle sooner/quicker and not raise it when coolant temps increase.

[tpepmeie]

BRXB is not a factory ZR-1 broadcast code. If it is that close to BFXB, then I suspect somebody has just renamed it. The Mask ID nomenclature ("AFa" vs. "AF", and so on) is not a GM term. Rather, it was coined apparently by TunerCat as a means to differentiate the various versions of a calibration within the same year. The Program ID byte still appears as AF in the calibrations, even though they are different programs.

Todd

[XfireZ51]

Originally Posted by tpepmeie

BRXB is not a factory ZR-1 broadcast code. If it is that close to BFXB, then I suspect somebody has just renamed it. The Mask ID nomenclature ("AFa" vs. "AF", and so on) is not a GM term. Rather, it was coined apparently by TunerCat as a means to differentiate the various versions of a calibration within the same year. The Program ID byte still appears as AF in the calibrations, even though they are different programs.

Todd

Todd,

Thanks for that clarification. Have you had a chance to verify whether the bin I posted is correct?