UA-65274002-1 Jump to content


  • Content Count

  • Donations

  • Joined

  • Last visited

About Geologist

  • Rank
  • Birthday 12/13/1972


  • Biography
    I have workerd too many jobs to list here, it is probably a boring read anyways.
  • Interests
    Earth Science, Cars (old and new)
  • Occupation
    I am not really a Geologist, well not YET anyways.
  1. Thanks for the info. I realize most people are these days, yet I have no facebook account.
  2. Update It may be a moot point now. I got impatient and went ahead and deleted the resistor I thought it was and replaced it with the potentiometer. I set it to 20k Ohms higher than the original and now the speedometer just stays at zero. Guess it was not the right resistor to replace. Please advise if you know where I went wrong. Thanks again.
  3. Geologist

    Scanner Help

    If I had the money, I would buy a Tech 2. From what I understand that is the best scan tool for GM vehicles.
  4. Got my 92 about 7 years ago. Had some under the hood wiring problems: 1) Wiring from Crank Position Senor to ICM got oily and melted the plastic causing a short that killed the car very unpredictably (easy fix but tough to troubleshoot). 2) A bad primary radiator fan kept blowing a fuse that would kill the engine when it kicked on (easy fix once you figure out whats causing it). The speedometer has been 20% off since I bought it (common from what I have heard) so I just use a Garmin usually. So far have put about 70k on it since then with nothing more than the typical electrical engine control goodies that die now and then. It sails on the freeway and gets high 20's for mileage (exhaust is not stock though). Sure it isn't as fast as my son's 2002 Regal with a 3800, but he still says it feels pretty strong in comparison. Overall I typically pick this car when going for a road trip, it just feels like it was made for it. What everyone else has said also seems valid.
  5. Hello everyone, I removed the instrument cluster from my 1992 GP and would like to bypass the calibration resistor for the speedometer. I have read a few posts by RobertISaar where he describes the resistor in question and states, "focus on the white blocks. you'll notice a large section and a small section on them. the large section on the 89-93 UB3 controls the gain for the speedo/tach needle. i remove the connections the PCB has to the resistor on those two pins and calibrate it using a 25-turn 500K potentiometer" OK, I have located the DIPP for the speedometer (see pic below) and have the appropriate potentiometer. I also posses more than adequate soldering skills (was my bread and butter for a few years). So my question is, am I reading which two pins to cut and solder the pot in place of. The blue arrows in the picture below is my best guess. Seems like Saar may be busy, so if anyone can affirm this is the right place to do the surgery it would be much appreciated before I do the cutting. Thanks for your help.
  6. Problem solved, kudos to Schurkey. The problem was the CPK wiring that runs under the engine. It was twisted (not sure if that is factory) and something had leaked into the loom and melted the coating on the wires causing them to short together. If you pulled the wire from the ICM it would back the tension off of the twist, opening the short, so testing it made it appear to be OK. After having been parked for several months (bought a different car) I decided to replace the ICM yet again with new coil packs. It ran for ~2 minutes then died. I noticed that it would fire briefly again only after pulling the CPK wire and plugging it back in, which is what inspired me to remove the wiring. I felt like a complete moron when I pulled the wires from the loom and saw the melted coating (the ONLY wires under the hood I had not completely removed from the loom). Replaced the wires and have put ~1000 miles on it, runs strong and never misses a beat! Thanks again to Schurkey.
  7. Thanks for the info Turbocharged. So do you really believe a brand new Echlin CKP with less than 2 hours on it failed to the point that it won't produce a clean enough waveform to trigger the ICM? Also this does not explain crank-no start for 5 days, replace ICM and it fires right up. Literally tried to start it, no spark, put my OLD ICM in and it started up and ran perfect for over an hour. On this ocassion it gave almost no warning that it was gonna croak, maybe a few minutes.
  8. Thanks for your reply. If I could afford a Tech2 I would be using one. Given the limited budget of a 40 yr old student who is also a father, that may not be for some time. I also suspected the new CKP sensor so I tested it several times. As a result I do know that the Crank Position Sensor is putting out 0.7V AC (at the ICM end of the wiring) during the crank - no start episodes (specs are between 0.3 and 1.7V AC I believe).
  9. After doing all of this to my 92 Grand Prix I am stumped and need help. Symptoms: After removing/replacing the negative battery terminal the car drives great till it reaches operating temp, then cuts out randomly during cruise, acceleration and deceleration (complete engine shut off, not just one cylinder) and will die as you begin to stop the car. The furthest it has ever gone is 60 miles or so before it just dies completely (crank – no start). At this point we checked it for spark and no spark at any of the coil packs. We tested the pink wire feeding the IC circuit and it has 12V (but oddly it has 0.14V less than the rest of the car at all times). Already Replaced with NAPA Echlin brand: ICM (3 different ones), Crank Position Sensor, O2 Sensor, Fuel Pump Relay. I also fixed all broken vacuum lines and several half-broken wires and cleaned up the grounds. History: 1992 Pontiac Grand Prix SE 3.1 4T60 trans, at around 169k miles the car just started to cut out randomly during cruise, acceleration and deceleration (complete engine shut off, not just one cylinder) and die as you begin to stop the car (sometimes it will drive perfectly for miles in between these little fits). At this point I repaired a few vacuum lines and put in an O2 Sensor. Ran better for a couple of days then cut-out and died completely (crank– no start) with code 42 (IC Circuit). At this point there is no spark. Replaced the ICM and the same thing happened: 2 days and dead with code 42. Replaced the Crank Position Sensor and same thing (this time no code 42). Put in my OLD ICM - fired right up, 2 days later dead again. Bought ANOTHER new ICM and it almost didn’t even make it home (8 miles), cutting out (AFTER it warmed up) almost the whole way like someone were just turning the engine off-and-on repeatedly. The car has good exhaust flow so I don’t believe the CATS are plugged, it also runs very strong. I use this car mostly to run to town (~20 miles) to take my son to school and pick him up. It has left me stranded twice now (luckily never with my son there) so I need to figure out where this ghost in my system lies. Does anyone have any ideas why it loses spark after warm-up on all 3 coil packs at the same time?
  • Create New...