Injuneer

From earlier question - what brand O2 sensors did you install?

I wouldn't call that a small cam. MAP is consistent with the cam specs.

Who burned the chip you have now? Running speed-density, the key element in the program is the volumetric efficiency (VE) table. That's part of the equation that the ECM uses to calculate mass air flow, which in turn drives mass fuel flow. Probably the biggest issue with speed-density. Any changes to air inlet tract (CAI, cam, head work) and the exhaust (cam, head work, headers) require a knowlegeable mail order tuner to figure the impact on VE. A dyno tune makes it much easier to get it right.

M93Z

I installed AC Delco 02 sensors.

Chip is from PCMforless, several years ago.

I provided a complete list of mods prior to the chip being burned and haven't changed anything since. After the tune the car always seemed to run rich but it ran well so I left it alone. Should have provided the original tuner with a scan[s] so as to allow the tune to be tweaked.

I believe that data logging with GaryDoug's software will provide enough info for an experienced tuner to figure out a decent tune however if there were a dyno tuner anywhere near me that is the route I would take.

As far as tuning goes does the speed density system require any more expertise than the later [94-97] OBD1 cars?

Thank you.

Injuneer

To me the main difference is the VE table's impact on the air flow calculation. The MAF in 94-97 eliminates that issue, for the most part. The MAF sensor measures mass air flow directly. Moderate changes in engine breathing are easily accommodated by the MAF.

However, the MAF cars still have all the features of the speed-density system, including the VE table, so that in the event of a MAF sensor failure, the system can default to speed-density. But that part of the tune only has to be good enough to keep the engine running until the MAF can be repaired/replaced.

And the flash programming would seem to make it easier to tweak the tune, compared to having to burn chips.

There has been some negative feedback on pcmforless since apparently Brian left. Alvin, who did the pcmforless chip tunes now has his own company, PCM of NC.

M93Z

I'm working on getting another tune, I see the chip burner isn't very expensive, the chip can be erased/reprogrammed, and it's possible to get the tune via email. Just a matter of trial and error. We'll see what happens. Thanks.