Hey everyone, my dads 1993 4.9 idles really high. You can put it in drive and it will go by itself. I ran KOER codes (KOEO test passed) and these were what they said:

SPOUT circuit open.
Cannot control RPM during KOER low RPM check.
Insufficient RPM change during KOER dynamic response test.

Can anyone please elaborate on what these mean? And what I can do to fix and troubleshoot?


Thanks.

 

Maybe throttle body blade needs cleaned along with IAC, purely a guess because I've never seen those codes.

 

It was sea foamed and I cleaned the IAC this time last year. Already thought about that lol.

 

Check or replace every single vaccuum line that you can find if you haven't already. A vaccuum leak can make all sorts of things happen. Like a bad ground does.

 

I know it's got a vacuum leak on the brake booster hose. Dad is going to pick a new hose up tomorrow though.

 

I would check every vaccuum and replace the lines. It's one of those things that's cheap enough to "throw money at" for peace of mind. My buddies truck had weird idle problems from a vaccuum leak. Fixed everything when we replaced the hoses.

 

I know it's got a vacuum leak on the brake booster hose. Dad is going to pick a new hose up tomorrow though.

 

There are more vaccuum lines than just to the brake booster. Did it always idle this high or is this something that happened all of a sudden?

 

siliconeintakes.com, engine dress up kit + 12ft of extra 4mm. This will get all of your vac lines in the engine bay. also need a 4-way barbed connector (or two 3-ways) for the 4mm, available almost anywhere.

I just ordered 22ft of 4mm and did all of the small lines, wish I would have sprung for the whole thing though, I got the red silicone and it really pops under the hood.

 

All of a sudden