scca28
October 27th, 2006, 15:27
My '88 Laredo 4.0 Auto with 115k had been giving intermittant problems since I purchased it a couple of years ago. All the usuals, bucking,stalling,wierd shifting etc., mixed with some good performance days. Also checked, replaced,adjusted all the usuals, so I won't bore with all the details. About a month ago I hit a low point when she just shut off while sitting at a red light, cranked and cranked with no hint of restarting, in front of a lot of traffic, and I had to endure the wrath of the angry mob and their horns while I pushed the Jeep off to the side. I popped the hood,pushed/pulled on some of the sensor connectors and relays, and she fired right up and was fine the rest of the day. The next day I finally took the time to do something I've been wanting to do for a long time.
First, I pulled every relay and cleaned, scotchbrited all the contacts, then coated them with Deoxit. Next,I disconnected each sensor plug and using tiny needle nose pliers,I crimped down on all the female halfs of the connectors to give a better mechanical connection. I also gave these plugs a shot of the Deoxit.
Now,knowing the nature of these beasts,I am typing this with one hand and knocking wood with the other the whole time, but it has been a month and this is the smoothest this Jeep has ever run. None of the above symptoms so far. I have no idea which connection was giving a problem, could have been more than one. My point to all this is sometimes you may replace a sensor to fix a symtom, and it might seem like that was it for a short time, then it acts up again. This could be due to the fact that the action of unplugging and plugging in a new part gives a slightly better mechanical connection, but if there is not a good solid contact between the two halves, you can still have a build up of oxidation that will mess with your sensor signals. Using a meter probe to check the TPS may also give this effect. You might get a good reading while the probe is jammed in there, but the sensor or computer may not see the same thing later. I know it's a long winded suggestion, but check/tighten up those connections before throwing lots of costly parts at your vehicles.
First, I pulled every relay and cleaned, scotchbrited all the contacts, then coated them with Deoxit. Next,I disconnected each sensor plug and using tiny needle nose pliers,I crimped down on all the female halfs of the connectors to give a better mechanical connection. I also gave these plugs a shot of the Deoxit.
Now,knowing the nature of these beasts,I am typing this with one hand and knocking wood with the other the whole time, but it has been a month and this is the smoothest this Jeep has ever run. None of the above symptoms so far. I have no idea which connection was giving a problem, could have been more than one. My point to all this is sometimes you may replace a sensor to fix a symtom, and it might seem like that was it for a short time, then it acts up again. This could be due to the fact that the action of unplugging and plugging in a new part gives a slightly better mechanical connection, but if there is not a good solid contact between the two halves, you can still have a build up of oxidation that will mess with your sensor signals. Using a meter probe to check the TPS may also give this effect. You might get a good reading while the probe is jammed in there, but the sensor or computer may not see the same thing later. I know it's a long winded suggestion, but check/tighten up those connections before throwing lots of costly parts at your vehicles.