H2obio

Ok, I'm at wits end. I've replace the IOC and the TBI gasket and she's still throwing a 35 code..................suggestions?

Gumby22

What do you mean by “IOC”? I can guess but clarity is important.

Code 35 sets when the idle speed is higher or lower than the calculated idle speed by more than 150 RPM for greater than 20 seconds.

1) Have you cleared the codes since the repairs you made?

2) Can you tell if the idle speed is actually high or low? Spec is 550 RPM at hot idle.

3) Are there any other noticeable issues such as extended cranking, stumbling/stalling, hesitation during acceleration, etc?

H2obio

Sorry, Typo. I meant IAC.

I have cleared the codes since the repairs and rescanned to confirm. The code seems to return only when I'm idling while opening ranch gate, weird.

The idle speed appears high at hot idle, around 750. I was going to try and adjust that down.

The truck was owned by a mechanic with his own shop and was well cared for. She doesn't have any other issues, with the exception of a hard shift from first to second only. Idles pretty sweet, starts immediately.

Thanks for your respnse. Ron

Gumby22

I figured it was a typo but there’s a lot of terms/acronym’s out there and I didn’t want to assume anything.

It makes sense that the code is setting when you’re opening a gate - that’s enough time for the ECM to monitor the idle speed and set the code.

First verify the throttle plates and pedal cable are moving freely and not binding or catching. With the cable disconnected, the pedal should fall freely to the floor. If equipped with cruise control, disconnect the cable for that from the TB and recheck idle speed.

If no problems, Warm the engine to temp and shut it off. Then disconnect and plug every vacuum port you can find - brake booster, MAP sensor, purge valve, transmission modulator, etc. Recheck idle speed - if it seems normal, rev the engine a couple of times and see if it returns to the same speed.

If it remains normal, reconnect the vacuum accessories one at a time - if the speed increases for one particular component (brake booster, for example) that’s a vacuum leak. Repair as necessary and recheck.

H2obio

Thanks Gumby, does it make sense to pull the plug and adjust the idle down?

Gumby22

First I would verify there’s no other cause of the high idle. Adjusting the idle stop screw would only mask any problems that currently exist.

H2obio

Thanks, I'll give that a try later today or tomorrow.

H2obio

Ok, following up. I couldn't identify any obvios vacuum leaks so I went ahead and pulled the throttle adjustment plug out (that was less than fun.... ....)..........I adjusted the throttle down and it appears that the error code has disappeared.............Am I missing something?

Thanks for the help!!