Ok i have a 4 cylinder 1991 TR, done just over 270000 kms. Ok heres the problem, when accelerating with OD on and power mode OFF, i can rev up to just over 4000 revs without hassle. If i plant the foot it will go to rev over 4000 then the engine will struggle VERY badly, it will shudder and the car will seem like its trying to rev but cant, making a wierd sound. Now if i take OD OFF and power ON, it will do this problem at 3500 revs and over!. Any ideas on what this could be?
I had the car serviced awhile ago and it seemed to stop the problem for about a week :(.
If i cant get this prob fixed i might have to sell my car :(.

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Greetings All.

Maybe an engine rebuild is in order?

Cheers,
--Tonba
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I feel that it's a transmission issue; the fact that it revs past 3500 fine with OD off, and PWR on rules out the engine as being the cause.

PWR off - Transmission upchanges earlier, downchanges later
PWR on - Transmission upchanges later, downchanges earlier
OD on - Enables 4th gear, provides torque convertor lockup whilst cruising constant speed
OD off - Disables 4th gear, prevents torque convertor lockup which = more slip/heat/wear


This should answer your question; you may need a transmission service or rebuild.

nooo it DOESNT rev fine after 3500 with OD off and power ON. It does the problem sooner, cuz with the od and pwr reversed it wont do it until over 4000 revs.

ok i've just went out driving and tested it again, it seems to only do it when the accelerator is near/on the floor, it almost sounds like the sound you hear when your car runs outer petrol (like a putt putt sound).

does your car have a rough or fast idle? if it does then i would suspect your fuel pressure regulator isn't holding enough pressure, this would explain the leaning out at high rpm. it could also be a spark misfire issue like worn leads or distributor cap or the elec plug into the top of the distributor is corroded. search this site to find out more about the plug it's a common fault in magnas and 6cyl VL commodores which both had the plug facing up to collect water. :nuts:

can you red line it in nutral? or does it missfire then too? (dont be to affraid to rev it around 6000rpm for short time)

tho only do it when the car is warm, just slam the accelerator to the floor for a second and watch the revs fly ;)

if it revs fines in 'N' then i's look into tranny problems , or ecu

ok had a look at it with TEK at the cruise, it will rev fine to 6000 in neutral, and in drive he said it wasn't transmission it almost sounds like a rattle :confused: .but i wouldn't care about a rattle if it didn't effect the car but it struggles to rev.

rattle like detonation?? (pinging)
can you manually adjust the timming on those things?

HAHA GUESS WHAT, the $9 spark plugs completely fixed the problem! i can now rev well over 5000 in D without any shudder or hesitation, ahhh i'm so relieved :D