Hard shift into D and R and high revs when in P and N?

[Overlord475]

Hey guys,

I just bought my first KJ (3.7L 4x4).

I've been driving a manual for years, so perhaps I'm just not used to the tendencies of automatics, but...

The trans seems to hesitate to shift into R and D, and then shifts hard into gear. Perhaps the pump is weak?

The idle also increases from 1000 to around 1750 when the trans in disengaged into P or N. Perhaps a MAF issue or IAC Valve?

Also, the OD button doesn't seem to be working either. I don't know if this is connected to the trans hard shift issue.

Thoughts?

 

[NJallDAY]

How many miles are on it? Do you have any service history? Perhaps a shift solenoid issue

 

[Overlord475]

How many miles are on it? Do you have any service history? Perhaps a shift solenoid issue

Apart from the carfax I have no service history, and there's not much on there.

The truck has aroud 129k on it.

It also seems to have an issue down shifting, while driving to work this morning I noticed that if I let off the gas the rev's stay were they are and very slowley fall. And in some cases will even increase until it get's high enough to shift into the next gear.

Thoughts? I think there's a pressure issue in the trans.

 

[Overlord475]

Checked the trans fluid level and it's an 1/2" above the "Hot Max" dot when the engine has been sitting and is cold.

I think there's a bit too much fluid in the trans, perhaps building up too much pressure?

I'll recheck this afternoon after the trans is up to operating temps and is running.

 

[rockymountain]

Checked the trans fluid level and it's an 1/2" above the "Hot Max" dot when the engine has been sitting and is cold.

I think there's a bit too much fluid in the trans, perhaps building up too much pressure?

I'll recheck this afternoon after the trans is up to operating temps and is running.

You need to check it while its warmed up completely and running in neutral.

 

[mikeandamy]

I've had similar issues with '02with118k. had the "drop" into gear but seemed more because the idle is high. shifting into p or n rpms go from like 800 to like 1600. i replaced the tps but still have the same issue. going to replace the iac next. if i find anything out i'll let you know

 

[Overlord475]

You need to check it while its warmed up completely and running in neutral.

That's what I meant I'd do this afternoon. Thanks for the info though!

I've had similar issues with '02with118k. had the "drop" into gear but seemed more because the idle is high. shifting into p or n rpms go from like 800 to like 1600. i replaced the tps but still have the same issue. going to replace the iac next. if i find anything out i'll let you know

Please do! I know when I bought the truck the guy said he had recently replaced the IAC valve.

Will update this thread as I find out things as well.

 

[Overlord475]

It was the IAC valve!

Remember to unplug the positive lead to the battery for at least a minute.This gives the comp a chance to relearn correct idle speed.

EDIT: Also the trans fluid is very high. At operating temps with the engine on, the stick read an inch above the "Hot Max" dot. It was on the wavy part of the dip stick.

 

[mikeandamy]

finally had the chance to replace my iac and now the jeep runs smooth as can be.