2 Issues, hopefully connected

I bought an 89 Trooper 2.6 automatic for my kids to use hunting/mudding/whatever so they would stay out of my truck! Engine supposedely rebuilt last November. It does have a leak around a fuel injector (no issue, ordered fuel injector seal kit for all). Here's my problem(s): when cold, it cranks and idles fine. Drive down the road when still cold, it shifts fine (except for not wanting to go into overdive, but it hasn't warmed-up yet so that's normal) After it warms-up, the idle starts fluctuating from 800 RPM's to about 1800 RPM's and the transmission can't seem to make up it's mind on shifting from 2nd to 3rd. It wants to go back and forth a couple times on the shift. I'm thinking leaking intake gasket since it obviously was put back together in a hurry (hence the punched injector o-ring). WOULD/COULD A LEAKING INTAKE CAUSE BOTH PROBLEMS? The lady I bought it from was the original owner and said neither problem existed until the engine was rebuilt. ANY OTHER THOUGHTS???

more info..............
drove it around town this afternoon. The A/T Oil Temp light came on. NOT BLINKING, just came on. Drove it home and let it sit for a while, cranked it back up and it was off. Fluid level fine, not burnt or scorched. Radiator coolant level fine also. No CEL. Haven't driven it again to check. I drove this vehicle 80 miles home when I bought it with no issues, other than the ones in my first post. Now drive it around town 8 miles and the lights come on!!!

Any help appreciated.

Hi, I don't have any personal experience with your model, but you do have a transmission control computer that will store codes that you can check. I don't know if the trans temp light would be stored, but if something is wrong it may store a code. The manual says you have an overdrive button on the shifter, are you aware of that on yours? http://library.alldatapro.com/alldata/LIB~C23944~R0~OB0~P3R0H~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/56221351/14617480/81310176/85953391/58876513

1.TURN IGNITION SWITCH (http://library.alldatapro.com/alldata/LIB~C23944~R0~OD~N/0/34870075/56622299/56623602/56623603/34853741/34857029/34859584/83370611) AND OD SWITCH TO ON</B>
Do not start the engine.
NOTE: Warning and diagnostic code can be read only when the overdrive switch (http://library.alldatapro.com/alldata/LIB~C23944~R0~OD~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/83370664) is ON. If Off the overdrive light will light continuously and will not blink.

http://library.alldatapro.com/alldata/LIB~C23944~R0~OB0~P3R0H~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/56221351/14617480/81310176/85953391/58876514


2.SHORT ECT Computer (http://library.alldatapro.com/alldata/LIB~C23944~R0~OD~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/83370650) DG TERMINAL CIRCUIT Black and Yellow/Black wire</B>
Using a service wire, short the DG terminal [Electronic Controlled Transmission computer (ECT Computer (http://library.alldatapro.com/alldata/LIB~C23944~R0~OD~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/83370650) ) terminal No. 24] and body ground.
http://library.alldatapro.com/alldata/LIB~C23944~R0~OB0~P3R0H~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/56221351/14617480/81310176/85953391/58876515


3.READ DIAGNOSTIC CODE</B>
Read the diagnostic code as indicated by the number of times the OD "OFF" light flashes.
http://library.alldatapro.com/alldata/LIB~C23944~R0~OB0~P3R0H~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/56221351/14617480/81310176/85953391/58876516


4.DIAGNOSTIC CODE</B> 1)If the system is operating normally, the light will blink 2 times per second.
http://library.alldatapro.com/alldata/LIB~C23944~R0~OB0~P3R0H~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/56221351/14617480/81310176/85953391/58876518


2)In the event of a malfunction, the light will blink once a second. The number of blinks will equal the first number and, after 1.5 second pause, the second number of the two digit diagnostic code. If there are two or more codes, there will be a 2.5 second pause between each.
NOTE: In the event of several trouble codes occuring simultaneously, indication will begin from the smaller value and continue to the larger.


3)Remove the service wire from the DG terminal.
DIAGNOSTIC CODES

http://library.alldatapro.com/alldata/LIB~C23944~R0~OB0~P4R0H~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/56221351/14617480/81310176/85953391/58876519

NOTE:


If codes 31, 32, 33 or 34 appear, there is an electrical malfunction in the solenoid. Causes due to mechanical failure, such as a stuck switch, will not appear.
If diagnostic code Nos. 21, 22, 23, 31, 32, 33 or 34 occur, the overdrive off indicator light will begin to blink immediately to warn the driver. However, an impact or shock may cause the blinking to stop; but the code will still be retained in the ECT computer (http://library.alldatapro.com/alldata/LIB~C23944~R0~OD~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/83370650) memory until canceled out.
In the event of a simultaneous malfunction of both No. 1 and No. 2 speed sensors (http://library.alldatapro.com/alldata/LIB~C23944~R0~OD~N/0/34870075/56622299/56623602/56623603/34853741/34857029/56218937/83370667), no diagnostic code will appear and the fail-safe system will not function. However, when driving in the "D" range, the transmission will not upshift from first gear, regardless of the vehicle speed.I think you are on the right track with the RPM situation. Some tricks can be found with a forum search to try and determine if it is a leaking gasket. Otherwise, check all vacuum hoses and fitting to be sure that they are in good condition and not kinked or cracking.

Thanks for the info! I'll check when I get home.

Where do find this stuff at??? The info is great!

Ernie

UPDATE.............

Had to replace seals on fuel injectores so I did that Saturday. LOTS of vacuum lines either rotted, missing or routed wrong so replaced all of those and corrected the routing according to diagram. Idle problem appears to be handled. Did not get a chance to drive to check on erratic tranny shift.

NEW PROBLEM............

Cranks when it wants to. It did this when I first got it. Thought it was the switch in the shift console so I cleaned it and it cranked fine until now. Turn the key and nothing! Does not turn, click or anything. I'm thinking starter but how many other systems are involved that are easy checks before I do that??????