I am having no luck getting my speedo to work correctly with my 7730 ECM and the digital VSS from a Quad 4.
I have the RSC set at 24000 pulses per mile, and the IPD set at 6.
I have tried burning the chips with a Willem burner and had no success. I tossed the Willem and bought a Moates. Still no luck.
In 1st gear, at 2000 rpm the speedo registers 50mph.
I reburned chips with IPD = 1 and IPD = 24 to see what happened. No change! What gives?
Details of my wiring are:
VSS yellow to B10 on the 7730
VSS purple to B9 on the 7730
B11 output on 7730 to buffer circuit using 1K , 22 K resistors, 0,1 uF cap, and a diode as detailed on Darth Fiero's website.
1K resistor on buffer to C203-F switched ignition
0.1uF cap output of buffer to C203-G speedo cluster input
purple from the speedo not connected per a note on Darth's buffer circuit diagram. It is a second ground, and is apparently not required?

I have checked and double checked my wiring. All of my terminations are neatly soldered and heat shrinked.
I have used up about 12 of the 20 chips I bought since they only seem to program error free so many times, and spend much of last season fooling around with this too.

I just had a thought. I am also partway through the digital cruise installation detailed by Darth. I have the servo installed, and the wiring on the servo connector redone per Darth's info, but have not tied the cruise input to ECM B11. I also have not removed and jumpered the cruise module connector in the passenger compartment yet. This does not seem it should influence the speedo or will it?
Does anyone have any suggestions?

Edit: I found a "clamp circuit" diagram that Rockcrawl use to have posted that only uses a 0.1uF cap and a 1K and 22K resistors, no diode. The circuit I am using from Darth's website has a diode on the buffer input. Whats the difference here. Could this be my trouble?
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Daviero - 88 N* GT

[This message has been edited by Daviero (edited 05-21-2009).]

Is the vehicle speed correct in the ecm? I would get it correct first then work on dialing in the speedo to the proper speed.

Are you using new or used chips? how many times are you reprogramming chips? you should be able to reprogram each one at least 50 times before they start giving you errors due to wear. are you 100% sure your burner settings are correct? If so your burner could be defective. I also found that simplifying the computer used helps a lot. I was getting a ton of burning errors when I used XP, when I backed the computer back down to windows 2000 all the errors went away. Upgraded PC does not mean better when it comes to chip burning or ecm tuning.

If your burner is doing funky things, you'll never get a proper chip out of it, so it can cause issues in the car.

quote Originally posted by fieroguru: Is the vehicle speed correct in the ecm? I would get it correct first then work on dialing in the speedo to the proper speed.

Interesting thought...I think this is a value I can check real time using TunerPro

quote Originally posted by timgray: Are you using new or used chips? how many times are you reprogramming chips? you should be able to reprogram each one at least 50 times before they start giving you errors due to wear. are you 100% sure your burner settings are correct? If so your burner could be defective. I also found that simplifying the computer used helps a lot. I was getting a ton of burning errors when I used XP, when I backed the computer back down to windows 2000 all the errors went away. Upgraded PC does not mean better when it comes to chip burning or ecm tuning. If your burner is doing funky things, you'll never get a proper chip out of it, so it can cause issues in the car.

I am using new chips. Lucky I bought a pack of 24. I have tried so much and used most of them up already. I find about 10 to 20 burns is all they are good for. I have verified every burn with the bin, and just to be sure, I have even read a burn back, saved it as a new filename, loaded that back into Tunerpro to see that the "read" file was correct. It was, so the verify function was correct. But still no change on the speedo
I am using XP on my computer. I will try 2000. Thanks for the suggestion.

What about the diode and the incomplete cruise conversion. Are they valid factors?

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Daviero - 88 N* GT

Deleted, re-read post. My .02 was wrong.
Mike

[This message has been edited by mswenson289 (edited 05-21-2009).]

Dumb question most likely, but if you are using a stock trans/vss, then you should set the PPM in the file to 4000? At least that is the way it works in my obd2 stuff.

[This message has been edited by darkhorizon (edited 05-21-2009).]

I agree. My Fiero has a FWD Getrag with the magnetic VSS, and it operates at 4000 PPM.

The interesting thing is that if you take your previous reading (50 MPH @ 2000 RPM in first gear) and divide it by 6 (i.e. from 24000 PPM to 4000 PPM), the resulting number (about 8 MPH) is just about right.

But in any case, getting a VSS reading from the ECM would still be a good idea, just to cover all bases.

I run the 93 Getrag with the reluctor wheel VSS and the road speed constant needs to be 24000ish for the 7730 ecm to read out the proper vehicle speed (using the 8D mask).

quote Originally posted by Blacktree: I agree. My Fiero has a FWD Getrag with the magnetic VSS, and it operates at 4000 PPM. The interesting thing is that if you take your previous reading (50 MPH @ 2000 RPM in first gear) and divide it by 6 (i.e. from 24000 PPM to 4000 PPM), the resulting number (about 8 MPH) is just about right. But in any case, getting a VSS reading from the ECM would still be a good idea, just to cover all bases.

You guys are correct. The ECM registers 10 mph when the speedo says 60. Yet the IPD is set at 6. I have verified this by reading the chip and comparing to a known bin. I am stumped with this. I have also tried IPD of 1 and 24 with no change.

I also have a major stumble from idle with even a small bit of throttle. Enough of a stumble to kill the engine sometimes if you don't catch it. The engine is a stock VIN 9 N* running on Ryan's 7730 ECM. I struggled with both these issues all last season. Never found the reasons. This is a brand new engine, not the poorly rebuilt one I ran last year, but has the same ailments except this one doesn't burn tons of oil. It seems to be running way rich though. Black sooty smoke after a stumble, when it does rev up a bit.
Anybody? Like I said, I'm stumped.

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Daviero - 88 N* GT