idle weird in reverse (1 Viewer)

[SS80]

i took my girl friends 80 up to the snow this weekend and while i was in 4 low reverse the rpms would bounce from 200 up too around 800 and the thing would jerk backwards...she then told me it had been doing that lately. anyone have any idea what it could be? i just did a trans flush and it is still doing it. any help would be appreciated

 

[jamisobe]

When she says its been doing it lately does that mean in high range as well?

Could be cap & rotor, spark plugs.

 

[SS80]

ya it does it in high as well but only sometimes. but it does it everytime in low. and from what i understand it has had a full tune up less then 2k ago.

 

[jamisobe]

ya it does it in high as well but only sometimes. but it does it everytime in low. and from what i understand it has had a full tune up less then 2k ago.

Was it doing it before the tune up?

 

[SS80]

i want to say yes, because she took it in when it was idling ruff. but im not 100%just wish she would have had me do it instead of a stupid shop that over charges

 

[jamisobe]

i want to say yes, because she took it in when it was idling ruff. but im not 100%just wish she would have had me do it instead of a stupid shop that over charges

I would say if it was doing it before they "tuned it up" you could take it back and ask them why it is still running rough.

If it started doing it afterward than you could take it back to them and tell them that immediately after their "tune up" your truck began to idle rough.

Sounds like ignition to me, but it could be bad fuel.

How many miles? Plug wires are much less likely but maybe...

 

[SS80]

i hope it isnt anything to crazy... thanks for the help tho ill have to take it down there and see whats up

 

[jonheld]

If it's only doing it in reverse around idle then have a look at the flexible tube between the air cleaner and throttle body. I had the EXACT same symptoms only in reverse low range. In high range there is less motor to body movement so it may not happen.

On mine there was a tear in the ribbed section just before the throttle body letting unmetered air in. Have a look at my website below for details.

 

[IdahoDoug]

Would be good to know what vehicle we're talking about here.

DougM

 

[SS80]

92 toyota land cruiser

 

[80jay]

check your intake for cracks mine did the same thing in 4 low revese, because the torque of the motor it would just move it enough to make the crack in the intake larger, and cause it to act funny.

 

[SS80]

how much was the intake?

 

[Dibbs21]

I had the same issue with my 91 in low gear reverse. There was a rip in the ribbed part of the cold air intake. I Accedently tore the whole thing in half trying to get it off to fix it. I went down to the local auto parts shop and bought 3" tubing and it fixed the problem. No more rought idling or stalling.