FIXED!!!!!-Smog failed due to EML light, did a drive cycle, now car is messing up! - Page 10

bcredliner · #91 07-13-2013, 06:29 PM

Your symptoms are also consistent with a bad DISA valve. I thought you already replaced it?
It could be leaking around the seal, that happens sometimes during replacement. Check the connector with engine running to see if it live. Bad DISA valve or a vacuum leak at that location can cause rough idle, hesitation and lean fault codes.

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upallnight · #92 07-13-2013, 06:33 PM

Quote:

Originally Posted by diddy0071

So I plugged in the OLD MAF, still the same issue. I decided to check the DISA valve. IT doesn't seem to be working with it plugged in or not.

http://i.imgur.com/06fAvic.jpg

http://i.imgur.com/cGVvtRQ.jpg

http://i.imgur.com/CqsxJVp.jpg

The DISA valve unplugged, doesn't do anything different. The DISA valve plugged in, same thing. I noticed the little cap to the plug for the DISA had a zip tie on it. I popped it off, and removed the cap. Maybe the connection just isn't working anymore.

Suggestions? FML.

Unless you have the truck on a dynamo you can't test the DISA valve by just plugging it and unplugging it.

The DISA (Dual Intake Resonace System) valve controls the variable length intake manifold giving better torque at low revs by closing keeping the intake runner long. After higher revs above 4k, it opens up by and makes the intake runners shorter for more horsepower.

bcredliner · #93 07-13-2013, 06:39 PM

start it up and test for vacuum leak at the DISA valve. Did you replace the valve or put the old one back in?

diddy0071 · #94 07-13-2013, 06:39 PM

Quote:

Originally Posted by upallnight

Unless you have the truck on a dynamo you can't test the DISA valve by just plugging it and unplugging it.

The DISA (Dual Intake Resonace System) valve controls the variable length intake manifold giving better torque at low revs by closing keeping the intake runner long. After higher revs above 4k, it opens up by and makes the intake runners shorter for more horsepower.

So if it is running the same, then how is the DISA the problem if we can't verify it is working correctly unless revving up higher than 4k? I unplugged it and revved it and still had an issue. I plugged it, revved it and it was the same.

I pushed it in all the way and tightened it all the way. I will take a picture to show how it is sitting against the manifold.

diddy0071 · #95 07-13-2013, 06:41 PM

Quote:

Originally Posted by bcredliner

start it up and test for vacuum leak at the DISA valve. Did you replace the valve or put the old one back in?

Replaced it with a DISA that was used, but appeared to be in working condition. The old DISA had a broken pin and the flap was loose. This DISA has the pin intact, and it also has the flap with a bit of tension, like a valve would be expected to have. The OLD DISA didn't feel like it had any tension. Upallnight sold it to me, he should know more about the condition than I.

bcredliner · #96 07-13-2013, 06:41 PM

It is not about a bad DISA valve it is about a vacuum leak at the valve or the DISA gasket. Start it up and check for vacuum leak at that location.

bcredliner · #97 07-13-2013, 06:42 PM

did you use a new gasket?

bcredliner · #98 07-13-2013, 07:00 PM

go to the last page of the thread---what did you do for you e53 today. There are pictures of a good and bad DISA valve.

diddy0071 · #99 07-13-2013, 07:05 PM

New Gasket?

upallnight · #**100** 07-13-2013, 07:06 PM

Quote:

Originally Posted by bcredliner

did you use a new gasket?

The DISA Valve does not have a gasket, the seal is built into the valve. If you look at the picture of the DISA in previous post you can see the seal. The DISA valve that I sold had the old seal material removed and a new o-ring install. The DISA Valve was working in my truck when I removed it. I removed it because I brought a new OEM DISA Valve with the factory seal insteal of the replacement o-ring.

The OP had the P0171 and P0174 code before he replace the DISA valve and still have the same code after he replaced the DISA Valve. Both of these code indicates a lean Condition in Bank 1 and Bank 2. A lean condition is either when there is too much air in the mixture (a vacuum leak) or not enough gasoline in the mixture (poor fuel pressure at the rail). He could have a vacuum leak at the CCV system such as at the return line from the dipstick to the oil pan a know vacuum leak item.

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