3.2 missing badly - out of town.....help requested

[198491132]

New SW Chip installed 250 miles ago. As I was just leaving Watkins Glenn a huge misfire started above 1500 rpms. Was able to get to my destination but can not move on until this is fixed. Called Steve W, he suggests a bad/cold solder joint on the jumper I added on the DME board, to allow for his chip to go to 4K Memory.

Why would the car run great for 4 hours, if this was the cause.

Do not have equipment to re-solder, but will get some later today.

I changed the DME relay, no good. Checked all the plug wires, injectore feeds, saw nothing that fell off.

Would a messurement of 461 ohms across pins 1 and 2 on the DG speed sensor be an issue? It is out of tolerence according to the manual...(960 +-). I did have to replace the ref sensor about 1500 miles ago. I could not remove the speed sensor, so it remained.

Would the car react the way it is if this is the problem? Terrible miss fire, back fire and wanting to shut down after 1500 rpms.....

I did replace the DME relay....and DO have a speed sensor in the car, issue there is I have to get it to a shop, as I tried for days yo get it out myself last Summer.

Stranded , out of town.....

Dave

[ccm911]

Dave:

Did the box under your seat come lose by any chance?  When you put in the new chip were you sure to tighten everything back up?  The box MUST be grounded, and the grounding is achieved by the bolts that hold it to the floor.  I have seen this happen in the past.  A friend of mine installed the chip, and then didn't bolt the box back in.  Same result as yours.

Best of luck.

[198491132]

Interesting.....I will go back and re-install..but yes, the four bolts where tight. And, it run good for 250 miles prior to this happening.

[Larry Herman]

I would go with the cold solder joint, or possibly a poorly seated prom.  You may want to remove the chip, inspect the pins and the socket and then re-insert it.  I have seen chips that are improperly seated cause all kinds of havoc.  All it takes is a little vibration (like 250 mikes worth) to loosen one pin.

[198491132]

I just walked in......speed sensor was bad. It measured bad via ohm meter with 461 ohms. Replaced it, (4 hours) and the trouble seems to be better. I have not test drove it yet, just finished minutes ago, but the revs go straight up in the garage. Assumng fixed unless tomorrow brings another issue.

Along the way....cleaned out the fuel filter, tested flow meter, and air gate. Oh, and found a squirel nut in the engine tray.

Interesting.......thank you for the quick responses. Many of us count on them!!!!!!!

 

Dave