Dinosauro
Member
Following Rangerj's checklist for DIS trouble-shooting, I found the following:
1. DIS module ground appears to be OK.
2. When cranking, tach does deflect slightly, hard to say how much, probably 100 rpm, but not 300 rpm.
3. PIP to EEC voltage is almost 13 volts static, 10.75 when cranking (not 3 - 7 Volts as Ranger specified.
Does this mean that my new (+- 2 hours old !) crank sensor has failed, or slipped out of adjustment ? Hate to pull the whole front end apart again and put the old (200K plus) sensor back in to find out !
All words of wisdom appreciated !
Dinosauro
OK, my apologies to everyone who responded ! My error in thinking that I could pick up this thread where I dropped it 1 1/2 years ago ! So, let me give you the whole story:
I bought my hi-mileage (212K) but very well maintained and near-mint 92 MTX about 2 1/2 years ago from my ex-wife's new husband, who had used it exclusively as a tow-car for his Porsche GT3 race-car. Poor old Bill couldn't remember if he had ever replaced the timing-belt, so after a couple of months of lining up parts and manuals, etc. I did the whole front end of the engine. Car had been running fine, only throwing one code, (Driver's air-bag faulty), so my efforts were totally preventative in nature. I replaced CPS, front crank seal, water-pump, all belts including timing belt while I had the front end opened up. Car fired immediately, and ran beautifully for about two months, until one day on the freeway, it dropped a couple of cylinders ! Code reader at that time showed it as a four-cylinder with no error Codes ! I determined that that it was dropping 2-cylinders which were paired on the Coil-pack. Easy diagnosis and repair ! I replaced the coil-pack and car immediately fired up and ran great on all six cylinders. (For 2 1/2 days!) Original symptoms returned, and I got home on four cylinders, when engine died, and would not restart. Could not pull Codes, so I started with the basics: plenty of fuel pressure, but no spark to the front 3 cylinders, and presumably to the back 3 which I didn't bother to check. I tried 2 other coil-packs - no change. I tried swapping the DIS module - no change. Cleaned up all DIS and coil-pack connections - no change. Swapped computers with two others - no change. Running out of components to replace (without tearing apart the front end to test/swap the CPS) I started testing circuits for continuity and proper voltage. I found, BTW, that the wire color-Codes did not correspond to Rangerj's listed colors, I presume, because of old-age fading, so I tested circuits at the listed pin-positions, and disregarded wire colors. For example, Ranger's listed Dark Blue was a faded gray at fourth-pin down on left side of DIS module. My colors, from top-to-bottom were R/lg, lb, blank, Gray, Y/lg and R/lb. While my memory has faded a bit from 1 1/2 years ago, my recollection is that I had gotten as far as checking the voltage at the IRCM (Integrated Control Module) where (I think) I found a lack of 12 Volts, and was toying with the idea of running a jumper with 12-Volts from the fuse block.
This is where I dropped it a year and a half ago, needing to get out and make some money, instead of "fooling around with my cars".
This week, I decided to start from scratch again, plugged everything back in, and started back through Ranger's DIS check-list.
Thus, my question above: Instead of the 3-7 Volts on the PIP circuit specified by Ranger, I got 12.9 Volts static, and 10.75 volts cranking between the 4th pin down on the left-side of the DIS module (Ranger's Dark blue, my faded Gray) and the negative pole of the battery.
Does this mean that my new (2 hours old !) CPS has failed or slipped out-of-adjustment ?
Thanks, guys !
1. DIS module ground appears to be OK.
2. When cranking, tach does deflect slightly, hard to say how much, probably 100 rpm, but not 300 rpm.
3. PIP to EEC voltage is almost 13 volts static, 10.75 when cranking (not 3 - 7 Volts as Ranger specified.
Does this mean that my new (+- 2 hours old !) crank sensor has failed, or slipped out of adjustment ? Hate to pull the whole front end apart again and put the old (200K plus) sensor back in to find out !
All words of wisdom appreciated !
Dinosauro
OK, my apologies to everyone who responded ! My error in thinking that I could pick up this thread where I dropped it 1 1/2 years ago ! So, let me give you the whole story:
I bought my hi-mileage (212K) but very well maintained and near-mint 92 MTX about 2 1/2 years ago from my ex-wife's new husband, who had used it exclusively as a tow-car for his Porsche GT3 race-car. Poor old Bill couldn't remember if he had ever replaced the timing-belt, so after a couple of months of lining up parts and manuals, etc. I did the whole front end of the engine. Car had been running fine, only throwing one code, (Driver's air-bag faulty), so my efforts were totally preventative in nature. I replaced CPS, front crank seal, water-pump, all belts including timing belt while I had the front end opened up. Car fired immediately, and ran beautifully for about two months, until one day on the freeway, it dropped a couple of cylinders ! Code reader at that time showed it as a four-cylinder with no error Codes ! I determined that that it was dropping 2-cylinders which were paired on the Coil-pack. Easy diagnosis and repair ! I replaced the coil-pack and car immediately fired up and ran great on all six cylinders. (For 2 1/2 days!) Original symptoms returned, and I got home on four cylinders, when engine died, and would not restart. Could not pull Codes, so I started with the basics: plenty of fuel pressure, but no spark to the front 3 cylinders, and presumably to the back 3 which I didn't bother to check. I tried 2 other coil-packs - no change. I tried swapping the DIS module - no change. Cleaned up all DIS and coil-pack connections - no change. Swapped computers with two others - no change. Running out of components to replace (without tearing apart the front end to test/swap the CPS) I started testing circuits for continuity and proper voltage. I found, BTW, that the wire color-Codes did not correspond to Rangerj's listed colors, I presume, because of old-age fading, so I tested circuits at the listed pin-positions, and disregarded wire colors. For example, Ranger's listed Dark Blue was a faded gray at fourth-pin down on left side of DIS module. My colors, from top-to-bottom were R/lg, lb, blank, Gray, Y/lg and R/lb. While my memory has faded a bit from 1 1/2 years ago, my recollection is that I had gotten as far as checking the voltage at the IRCM (Integrated Control Module) where (I think) I found a lack of 12 Volts, and was toying with the idea of running a jumper with 12-Volts from the fuse block.
This is where I dropped it a year and a half ago, needing to get out and make some money, instead of "fooling around with my cars".
This week, I decided to start from scratch again, plugged everything back in, and started back through Ranger's DIS check-list.
Thus, my question above: Instead of the 3-7 Volts on the PIP circuit specified by Ranger, I got 12.9 Volts static, and 10.75 volts cranking between the 4th pin down on the left-side of the DIS module (Ranger's Dark blue, my faded Gray) and the negative pole of the battery.
Does this mean that my new (2 hours old !) CPS has failed or slipped out-of-adjustment ?
Thanks, guys !
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