Low idle/Code 71 (1 Viewer)

[ryanrtxtx]

94 Land Cruiser had no air filter in it and I was getting a check engine light.

Bought a new K&N put it in. If I have the A/C on, it will drive. The second I turn the A/C off the engine stalls out. The check engine code of 71 - EGR System Malfunction. Where do I begin? I'm not a mechanic but trying to work on this thing myself. So any videos or detailed instructions would be much appreciated!

 

[jbatx]

The FSM has a thorough testing procedure for each part of the egr. I would send it to you but I don't know where my copy is at the moment. I am sure it's on mud

 

[Landseer]

The EGR code is very common and generally doesn't impact anything, its probably completely unrelated to the stalling issue. First place to look for the stalling issue is the intake tube, its known to develop cracks in the flex joint that let unmetered air into the system, try wrapping the flex joint in duck tape to seal it and see if that makes a difference.

 

[jbatx]

Actually a failure or leak in any part of the egr system will cause changes to idle and timing. If you know there's a problem (because there's a code), fix it first.

 

[ryanrtxtx]

Actually a failure or leak in any part of the egr system will cause changes to idle and timing. If you know there's a problem (because there's a code), fix it first.

Is the intake tube considered part of the EGR system? From what I can find the EGR system has quite a few parts. Just looking for the best place to start. For what it's worth the idle/stalling out issue only started when I put an air filter in. Clearly the previous owner didn't know what he was doing so he just took out the air filter to make it run. The EGR system code was on before the stalling issue. I figure I should start with the idle issue first and then see what it does to EGR. Right? Wrong? Thanks for the tips so far guys...

 

[ryanrtxtx]

The EGR code is very common and generally doesn't impact anything, its probably completely unrelated to the stalling issue. First place to look for the stalling issue is the intake tube, its known to develop cracks in the flex joint that let unmetered air into the system, try wrapping the flex joint in duck tape to seal it and see if that makes a difference.

I think you are right because the check engine light was on before I put the air filter in. Now adding the air filter has caused the low idle/stall out. I will check the intake tube.

 

[Landseer]

To put in the air filter you have to move the intake tube (big black rubber tube from filter to throttle body), moving it can definitely cause it to fail. This happened to me recently and wrapping the flex joint in duck tape solved the problem until a new tube arrived.

The EGR can cause problems beyond the check engine light if it sticks open but thats a very rare occurrence while the 71 code is extremely common and seldom causes any issue beyond the CEL.

 

[jbatx]

hmmm... Removing the filter would allow more air flow. If adding the filter caused stumbling and stalling I would start with..

1. Ensuring all intake tube connections are sealed and tight. I'd pay attention to anything on the manifold side of the MAF.

2. Cleaning the T body and MAF and then testing.

3. Maybe a bad injector or wiring...

...make sure all those hoses and gaskets are in good shape.

I suspect a rich condition, hence the reason you're seeing the issue by adding the filter.

So, really I don't think it's actually a vac leak... I just like to make sure to eliminate all variables like loose and leaky stuff.

..Or the filter is a red herring and I'm over thinking it. Maybe you knocked something when install it as previously mentioned

 

[ryanrtxtx]

hmmm... Removing the filter would allow more air flow. If adding the filter caused stumbling and stalling I would start with..

1. Ensuring all intake tube connections are sealed and tight. I'd pay attention to anything on the manifold side of the MAF.

2. Cleaning the T body and MAF and then testing.

3. Maybe a bad injector or wiring...

...make sure all those hoses and gaskets are in good shape.

I suspect a rich condition, hence the reason you're seeing the issue by adding the filter.

So, really I don't think it's actually a vac leak... I just like to make sure to eliminate all variables like loose and leaky stuff.

..Or the filter is a red herring and I'm over thinking it. Maybe you knocked something when install it as previously mentioned

Thanks for the detailed info... I did find a crack in the intake tube. Got the part ordered and will install it tomorrow. Hoping that's the only issue. Appreciate all the help guys!

 

[jbatx]

Thanks for the detailed info... I did find a crack in the intake tube. Got the part ordered and will install it tomorrow. Hoping that's the only issue. Appreciate all the help guys!

Was the crack before or after the MAF?

 

[ryanrtxtx]

After MAF