QuestionQUESTION: Engine is hesitating or tranny not shifting smoothly before reaching operating temp. Virtually gone after warm-up. Issues when shifting 1>2 & 2>3. Noticed issue after adjusting idle speed, timing to 10 deg BTDC (was @ 20 deg BTDC @ smog check), the accel and throttle cables. No trouble codes even after disconnecting solenoid wires at the AT for manual drive. I tested cold start injector resistance, cold start time valve, eng temp sensor & air intake temp sensor. All OK.
I have official Toyota manuals (2 books + AT repair manual), but can’t figure it out. Did I OVER-tweak cables or could my ECM be going?
Thanks for all of your much help!
ANSWER: Recheck the throttle pressure cable again, make sure it's adjusted per the repair manual, there should a distance of about 1mm between that small metal sleeve and the end of the pressure cable housing with the throttle closed.
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QUESTION: Rechecked Throttle Cable per the repair manual, except with it closed (Not open as manual states). Cable stop sticks out of rubber boot only 1mm or slightly less. Can the cable become over-stretched? It's probably original. I still can't figure it out.
No noticeable issues after engine is warmed-up (5 minutes +/-). I've looked at the repair manuals over and over and I am getting no where. Any other thoughts?
Good news is that it passed smog w/ flying colors. Max HC @ idle in California is 100, previously tested @ 131 (failed). Changed timing as indicated previously, changed oil & filter, cleaned out air intake manifold @ throttle valve, and brought it in warm to smog check. HC @ idle were only @ 9. Amazing.
By the way, a few years back you talked me into swapping out a window regulator. You gave me great advice (and support) and it was a relatively easy job. Thanks
Curtis
AnswerThe throttle pressure cable only has an effect on shift quality, either too soft or too harsh, it does not determine upshift/downshift points, this is why I recommending checking the adjustment because you said that the shifting was not smooth when cold. If the cable was stretched the shiftpoints would be too soft, almost slipping between gears, this doesn't seem to be the case. What I would suggest doing at this time is to drain all of the transmission fluid out, preferably using a power flush machine to get all of the fluid and then refilling it with the correct fluid(DEXRON II or III(preferably)I base this on the fact that it seems to be temperature related and transmission fluid like any other liquid changes viscosity with temperatures and the fluid may be old or possibly the wrong type of fluid.
