2.6L Misc tech info
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Misc technical info found on planetisuzoo forums:
2.6L Cylinder Head related info:
When removing the head, the intake needs to come off with the head because the battery table is in the way - the intake won't clear the studs before it hits the battery table.
Head Bolts: 12mm 1.5 tap size needed to clean out bolt holes in block. Squatch says: The only bolts that I am aware of on the 1st gen Troopers that Isuzu says to replace are the bolts holding the flywheel to the crank. Head bolts are fine to reuse. Ed Mc. says: Neither 2.3 or 2.6 head bolts are Torque-to-Yield. Period. If the head bolt threads are in good condition, and the allen socket heads are not stripped out, you can clean the bolts and re-use.
Head castings: Casting number is cast on the back side of the head - very large size number. Heads with a casting of 1 or 2 (mid 80's vintage) were prone to cracking whereas castings with 3 or 4 were much more reliable.
Jerry says: 97 WAS THE LAST YEAR FOR THE 2.6, IN THE RODEO AND THE PASSPORT, NOW A LITTLE CAUTION , THERE ARE 2 DIFF 2.6 CYL HEADS IN USE, AND YOURS HAS WHAT IS COMMONLY CALLED THE HI COMPRESSION HEAD WHEN INSTALLED ON THE 92 AND EARLIER 2.6 ENGS, BE sure OF THE CYL HEAD YOU GET AND MAKE ABSOLUTLY CERTAIN THAT IT IS THE CORRECT HEAD ANY 94 AND LATER 2.6 HEAD WOULD BE THE CORRECT ONE AND SOME OF THE LATE 93 EVEN HAD THEM, NO 92 ENG HAD THIS HEAD, IF YOU USE THE OLDER HEAD ON YOUR (newer)ENG YOU WILL HAVE ABOUT 7.0 TO ONE COMP , JERRY
oldestisuzuist says: Sometime around '92 the 2.6 pistons were changed from the older shallow circular dished top to a deeper pie-shaped dish. To bring the compression back up the head chamber volume was decreased. Using this later head with earlier style pistons gives a compression boost similar to using a 2.3 head, & it's EFI with the larger valves. Seems like I read that they did away with the air pump with this mod- can anyone confirm- if so it might not be an option for you if it doesn't have air pump ports.
2.6L Balancer: Squatch said: You probably didn't cross thread that (balancer) bolt. Some of the 2.6s had a damper that had a funky groove for the key. The woodruff key engages both the damper and the lower timing pulley. If the damper doesn't seat correctly you have almost no engagent of the key with the damper. This can also happen if that key is not perfectly flat. The damper will start to wobble and move back and forth (side to side rotationally) on the crank. It may actually sound like a rod getting ready to go. I'd make sure that you have a perfect slot that is only wide enough for that key in the damper. If it is distorted at all or has the 1/2 length double wide groove replace it with a NEW ISUZU damper. I found this out many years ago AFTER I bought a remanufactured 2.6 for my 1st Trooper. I went to pull the engine and the damper was flopping around. Also sometimes the crank will leave an indent in the inside of the damper that leeps it from seating properly. Again replace it.
2.6L Coolant Temp Sensor:
Under side of intake manifold, showing Thermo sensors and Auxiliary Air Valve. (1 == some other temp sensor?) (2 == temp sensor for dash guage) (3 == temp sensor f0r ECU / ECM) (4 == auxiliary air valve -provides fast idle when cold)
dlutt said: I just finished changing the temperature sensor. The only thing that was moved was the charcoal canister (easy, it's clipped in). The method was inspired by ajm291's approach. This was done on an '89 Trooper with power steering and air conditioning. The whole process took about twenty minutes.
The sensor was directly accessible from beneath the vehicle using a 3/8 socket set with multiple extensions. No universal joint was needed. The extensions had to be angled just a bit to get the socket through a tight spot. Also, because of the angle, the extensions needed to be attached in in two phases. In other words, get it started upwards with about 8" of extension and once past the tight spot add the additional extensions to get to the sensor.
Here's a major trick to this job. Use a 13/16" sparkplug socket instead of a 19mm socket. There's two reasons for this. First, a 19mm socket probably will NOT clear the wiring plug. A wrench will fit the sensor but, a deep 19mm socket will not slide past the wiring plug while a 13/16 deep socket will. Second. a 13/16" socket gives just enough wobble to negate the need for a universal on the extensions. The access to the temperature sensor is slightly angled and the wobble factor is needed. This method had the sensor removed in about three minutes.
Threading the new sensor in took a bit longer. After moving the charcoal canister I was able to snake my arm under the the manifold and start the threads of the sensor. This was done from the top, over the fender. It took a few tries and I dropped the sensor a couple of times but finally success was achieved. Incidentally, the sensor is close to being under one of the thermostat housing's bolts.
After the threads were started the socket was once again employed from beneath the vehicle and the sensor was easily and quickly tightened.
