IAS Failure, what's it mean?

[Gez89SHO]

I was checking codes and it gives (among others)
Code 551 - IAS failure.
Anybody know what this means? What's IAS?

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Gezim
1989 Currant Red
coneless, painted SHO lettering
Subframe Connectors, 16x7 Team Loco 143's

gzim.freeservers.com
LSHOC member

[email protected] IM: gzimi

 

[bigdoggee]

How is your car acting and do you have oil in the spark plug wells? I had the same code... it turned out that a couple of my spark plug wires had shorted out from having oil in the plug wells!!

 

[RStalveyARFF]

Gezim, is this being pulled on your 89? If so, you are reading the codes wrong unless you have a Gen II computer... 89-91's spit out 2 digit codes.

 

[Gez89SHO]

Thanks for the replies guys.
The code is actually from my friend's 92. He was complaining of nonlinear throttle response (bad throttle linkage maybe), lots of oil use, and loss of low rpm torque. I'll ask him for other symptoms.
We ran the codes then we went to remove/reseal his intake and valve covers.
We found that his secondary vacuum solenoid wasn't plugged in-that explains the low end loss.
There was also a oil trail pretty much all around the front valve cover, also there was a little oil in 3 ignition wires-2 front and 1 in the back. Not too drastic though, and the rear valve cover was pretty much dry.
We RTV'd the front valve cover in place and put it back together. (No time to do the rear one, it was getting dark and cold)
The oil in the wires explains the IAS code, I guess. But does any one know the definition? I'm curious now.

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Gezim
1989 Currant Red
coneless, painted SHO lettering
Subframe Connectors, 16x7 Team Loco 143's

gzim.freeservers.com
LSHOC member

[email protected] IM: gzimi

 

[luigisho]

I think you should get a fel-pro gasket kit and replace those upper gaskets. I'm not sure how long I'd trust rtv on leaky gaskets. The oil in the plug wells could have fouled the plug wires. I think most people replace the wires when they reseal. If you think seals are expensive (and they are) try multiple spark plug wire sets. In my opinion, if your're gonna open it up, you might as well put new stuff in and hope you don't have to do it again for a long time. Just my $.02.

 

[bensho92]

the IAS is the thingy on the throtle body that controls the idle, if you can take it of and clean it up it will make big diference in performance, it did in my sho,