4JG2 auto trans problem

[batosai]

Hi every one im new member of this club and I'm from Philippines..
Can someone help me with my problem. The stories goes like this, I have a 1993 Bighorn 4x4 w/ auto trans. The problem is when running at high speed for example 90-100 kph when i press the pedal to go faster the trans suddenly shif gears causing the engine to rev higher rather than go faster the mechanic said the the throtle cable is to tight so he adjusted it but still the same problem presist. But when I press the gas pedal slowly the shiting gears does not occur and I can run up to 120 kph @ 2900 rpm. What seems to be the problem with my tranny is it also normal for a bighorn to run 120kph @ the said rpm or it should only be around 2500 rpm? Is there a problem with this speed?

Thanks

[Bruce]

Try sitting on 80 K in o/d and then putting the foot down see if it changes back to 3rd then. 120K @ 2900rpm is pretty right in 4th O/D gear.
The trans may need a full service to.

Cheers Bruce

[geeves]

Revs sound right for top gear. The function you describe for full throttle is known as kickdown and according to my manual is normal for up to 115kph at full throttle in power mode or 108kph in economy. Its controlled by a kickdown cable that only operates at near full throttle. Drive the car at about 100kph and press the accelerator to the floor (be aware of your speed limits while doing this) The change down should occur at very near full throttle and change back into 4th at 125 - 131kph if you allow it to go that fast. Dont get any speeding tickets

[batosai]

Thanks sir Bruce..

@ Sir Geeves it happens to me ones im running at speed of 110kph then I try to go faster by pressing the gas then it suddenly change gears again causing the engine to rev high. Is it normal for the bighorn to run @ 125-131kph in 3rd gear? the rpm could reach the redline in 3rd gear @ this speed or I just need to loosen a bit more my kickdown cable so it wont shift gear easily and it would only shift a near full thortle. Pls enlighten me on this one.

Thanks again,

Batosai

[geeves]

Sorry Thinking about my post last night (should of been in bed when I posted it) The speeds in the book probably relate to a petrol engine.
Watch the rev counter at full throttle with the auto set on power it should change up at the red line which is about 4000rpm With the setting in normal or economy this should be about 3500rpm. I dont know what speed this relates to.
Only thing realy to note is that you should be getting a surge of power under these conditions. If not something is wrong

[batosai]

Ah I see but still running 120 kph @2900rpm on Diesel 4JG2 is still normal? Would their be big diff in terms of torque if I would just convert my A/t to M/T? Please advise.

Thanks agian

[geeves]

120kph at 2900 sounds about correct. They dont let us do 120kph here without sending us big bills so cant confirm but it relates to 100kph at 2500 in my bighorn.
The 2.8 Mu got the lower ratio diff so if they have standard tyres they are doing 3000 at 100kph

[batosai]

That also my average RPM @ 100kph I think theres no problem with my trans, I just need a little more adjustment on my kickdown cable. Are your rig equip with the EFI Injection system?

[geeves]

93 is non efi. Mine is the even older 4jb1

[batosai]

But they said that 4JB1t is more durable than the 4JG2 because it has direc injction that cause less EGT than indirect one.

[geeves]

clubisuzu.proboards.com/index.cgi?action=display&board=Justabout&thread=3092&page=2
We have examples of both motors over 400000km so engine reliability is good in both cases. However the 4jg2 does blow turbos due to a bad turbo design and is more prone to crack heads. Not sure if this is directly due to indirect injection.