Nope, all of the stuff has been cobbled from other cars... I will reset the PCM though -- haven't done that yet.


I'll post this today for you to check it out (if you have time!) It was supposedly a "stock" tune from a 1994 Camaro Z28 M6. I only changed a couple things -- the temps when the fans kick on (modified for a 160F thermostat), changed the speedometer calibration & removed VATS. Everything else was untouched.

That would be super helpful. I'll see if I can track down any other small vacuum leaks, like Fred said might be happening.

I replaced the MAF on saturday, but I haven't had a chance to log a drive around the block yet. I'll reset the PCM before doing another log, and see if anything has changed. I suppose it could also be a leaky injector, (partially stuck) so I also need to test for that still.

Thanks again for the helpful suggestions. Just a question -- is running this rich hurting my rings, or could this be indicative of rings going bad? I don't want fuel to get into the oil -- i believe that was what killed an engine I had before this one...

 

You're not running rich, because the BLM's are pulling out fuel to prevent it from running rich.

 

Hi Injuneer,

So does that mean even though I'm operating at 108 at the idle load, because the STerm counts are operating at 128 (sometimes a touch lower) the car isn't running rich?

If that's the case, that's very interesting -- the car still smells like it's running rich. Tonight I'll investigate other potential vacuum leaks. I have also reset the PCM now that the new MAF is in there.

I've posted my tune here:

http://dl.dropbox.com/u/24984984/94C...ler%20Mods.bin

Let me know what you think....

 

I took the car out for another spin last night after resetting the PCM and installing the new MAF. The readings have COMPLETELY changed -- very odd. The car ran horribly for the first couple minutes while in open loop but eventually settled down. It seemed like it was running better than before, but it's hard to say.

According to Datamaster, I'm actually running fairly lean now.

http://dl.dropbox.com/u/24984984/Apr...0reset%202.uni

Fred, I know you're a busy guy, but would you mind scanning through this new file and give me your expert opinion?

Thanks again,

 

Looked at your tune I can't see anything wrong as far as fueling settings. Your new trace looks like a different car.. The idle AFGS dropped from 8.0-8.2 at 800 RPM before to about 7.5 with the new MAS. So that will lean up your idle. However if you examine the new trace by expanding it and selecting TPS% and Left O2 Mv. You will see whenever you hit the throttle 0% up to 20% and enter BLM cell 6 then 10 during a shift the O2 Mv drops and holds .62Mv for about a second. ST BLM's climb to 160 (max setting). Looks like classic example of fuel starvation that was not there prior to MAS replacement. I am confused at this point, maybe someone will see something else..

 

Hi Bob,

Thanks for taking a look -- it really does seem like its a totally different car, doesn't it! Perhaps the PCM hasn't "taught" itself yet -- that was the first drive it had gone on since the PCM reset.

 

I believe when the car is cold the adjustments are stored setting using your recent driving and once the O2's warm up, they make the necessary changes. You should be fine after just a short drive and letting the car warmup.

 

Tyler, just something else I forgot. Noticed your speed never went above 15 MPH in the trace. I remember a while back you had a heck of a time getting the '93 M6 VSS to work with your Jag speedometer. Are you taping the VSS analog signal to a converter box to run the speedo or have you altered the PCM calibration settings and are running the converter box with PCM digital signal to speedo ?

 

Hi Bob,

I noticed that as well -- the Speedometer in the car now works and is basically accurate to a few mph. I've noticed that in Datamaster, the speedometer reading stays very low. I'll have to check with ScanTool to see if I get the same MPH readout.

I ended up calibrating the Speedometer output in TunerCats (adjusted the wheel size & differential.) I was still reading exceptionally high. The damper box had an adjustment ****, which I turned up/down until my speedometer was reading correctly. In the Jaguar there is a "Trip Computer" which has a read out of average speed, distance & mileage. The odometer in the Speedometer cluster is tied directly to the same electronic pulse, and is reading accurately.

While I was driving around the neighborhood I probably hit around 35~ mph a few times.

Would the VSS outputting a low speed possibly be causing this problem?

 

Speed feedback on an M6 is not as critical as the A4 requires for shifting and TCC. It is used for IAC throttle follower (prevents stalling during coastdown) and is used for BLM 16,17 and 18 selection 16= TPS 0% and speed = 0 MPH and , 17 TPS=0% and speed <0 MPH and 18 TPS not = 0% and speed = 0 MPH but sometimes a little higher ??. It should not effect fueling AFR at normal operation. One last question Is the MAS you are using the correct part number for a '94 F-Body '94 PCM ?

 

The MAF is for A 1994 camaro 5.7 so I don't think that could be the problem. The unit is a rich porter model, purchased new rather than rebuilt. I am going to run one last Datamaster read out to see if the PCM has corrected itself.

 

Hi guys,

So i took the car out on the freeway today -- speeds should have exceeded 75~mph. The Datamaster readout is still saying I'm only going 15mph tops. It seems like the RPM readings are accurate though.

On this voyage, the STerm and LTerm counts were very odd -- always indicating a lean running condition, with exception to some deceleration. I watched the histogram play out in DataMaster, and I was staying in the same few cells.

I'm not sure what to do regarding this situation -- the car seems to drive OK, but I have noticed that it is beginning to hesitate when i step on the gas now (since the PCM reset.)

If anyone has a chance to take a look, give me a suggestion on what could be wrong. The Datamaster readout can be found here:

http://dl.dropbox.com/u/24984984/Apr...12_Freeway.uni

It is very strange that the LTerm counts are consistently running lean (they were "pig rich" at 108 before the reset) and now the car fluctuates between a good AFR & a very lean one (up to 140 at times!). I'm pretty puzzled.

 

Do you have your egr system hooked up and working?
And also your charcoal canister system hooked up and working?

Generally your fuel trims should respond to the canister purging. Purging adds fuel vapors stored there from your gas tank when it purges. Usually at part throttle on a warm engine. It is duty cycle controlled so as not to get a surge of extra fuel when purged.

I'm seeing fuel added by the PCM looking at the fuel trims, not removed during the canister purge. Seemingly no stored vapors (not likely) or one of the lines is not hooked up.

The recording with the maf that has no screen, I would put no faith in that being accurate. The screen needs to be there for accurate air flow measurement, imho.

Also as Fred mentioned about direction of the air flow in the maf, also clocking position of the sensor may skew the readings.

Keith

 

The EGR system is hooked up and working, although it was an original part that came with the engine, perhaps it is wearing out. As for the Charcoal Canister system -- I had asked on a different forum if I needed to have the system hooked up to the canister itself. Right now, the system is just venting to the atmosphere -- the line going from the solenoid to the canister is not there. There is a vent line from my gas tanks going to the canister, and a fresh air inlet... but nothing going to the actual solenoid.


That would be correct... do'h! I'll hook the lines up to the canister and see how that changes the readings.

Yeah, I'm using a *new* MAF now, RichPorter is the brand. It got OK to good reviews online.


The MAF is set up correctly... On the note of the CCP system -- if I were to just delete this in TunerCats, do I need to adjust any other settings, or can I remove it and it will work okay?

 

I hooked up the canister purge system with the Camaro charcoal tank. I'll see if this makes any difference in my readouts. I'm guessing that is where the intake leak was coming from, but I'll see soon enough. Thanks so much for the continued help guys!

Does anyone have any idea why the Datamaster read out for the speedo is so low? I'll test it with FreeScan to see if DataMaster is just having trouble reading the VSS signal... but it's odd that it never gets above 16mph...