Ok, checked my timing and it was about 10-12 degrees retarded. Put it back to 10* BTDC and i now have my power back. She feels like she's running just as good and she was B4.

Did the KOER test again and got 2 codes, only one new. 44 again, but as i previously stated thats cause i bypassed the smog pump with my new exhaust.

13: Cannot control RPM during ER Self-Test low RPM check.
I read a little bit and have learned that this could mean a bad IAC or perhaps a vacuum leak, any other suggestions or maybe ways to narrow it down.

 

I bet I'd pull my codes more often if I had a reader. I'll have to put that on my list of stuff to buy.

 

andy, when i first got my innova 3145 i was asking anyone with a ford if i could check the codes for them.

very addictive.

you should have one.

QL2

 

Sold!!!!

 

Me too! I do the same thing, offer to read everyone codes!

I've had the OBD2 system for my laptop long before I got the 3145, was always looking for someone with a 96 or newer with a CEL on so I could use it!

We only have the one car that is OBD2, it rarely if ever has a problem. (knock on wood)

I aways hit up my tenants when I see em with a hood up, great time to offer to help! (show it off hehehehe)

 

I know what you mean.
I got mine at Amazon.
Did anybody buy the extension cable with it?

 

Did you pull the SPOUT jumper (shorting bar) out when you set the timing?

Pull the IAC valves plug off with it idling, the rpm should drop and the may die, if it does this the valve is working.

If no change you will have to do more tests if the valve, wiring and so on. You may be able to take it off and clean it.

 

Yes, and i checked it again afterward to make sure the EEC was controling the timing. It was advancing the timing anywhere between 1*-5* extra.

I'll get to that soon, but there's a rainstorm tonight, and my shop is full.

 

Well i pulled the IAC off while idling and nothing happening. I cleaned it and tried again, still nothing happened while unplugged. So i went out and bought a new one, installed it with a new gasket. Same old story, idles the same and when unplugged no change in rpm or idle. Don't think i would've gotten a bad one do ya?

Did another code check, got 13 again on KOER so i could still have a vacuum leak, did a vac pressure check and was getting 19-20. Also sprayed carb cleaner around gasket edges and received no increase in idle.

KOEO is 11 all good.

New code on CM now is 63: TPS circuit has intermittently failed below minimum 0.6 volts.
My TPS is but about 4 months old, the one before it was only a couple years old. And when i unplug my TPS the idle goes ape**** and heads on up to 2k+ rpms. Maybe it got uncalibrated, but it still functions.

 

If your throttle plates are closed and there is no change when you pull the plug off the you will have to check the voltage at the plug of the IAC.
At Hot-Idle you should get 7.5-10.5 DCV on the white wire with a blue stripe.
The red wire should always be 12 VDC with the key on.
You may also have bad wiring from the IAC to pin#21 on the PCM Computer.

 

Well the red wire read 14.5 vdc, which is normal, that's what my alternator puts out. The white wire read 11.55 vdc at around 8500rpms. When you increase the throttle the voltage drops. So my connection is good, still no change in idle when you unplug the IAC. I'm really starting to think that the parts store sold me a bad IAC.

Did an error check, got the same codes 33 & 63 on CM. 13 on KOER. I checked my tps while the engine was off and while the engine was running. Same results on both, the TPS is @ .8vdc at closed throttle and increases smoothly upto 4.5vdc WOT. My tps is good.

Is there any way to test the IAC itself that will totally confirm it is bad, or is knowing that there is a good harness connection and unplugging it w/o a change in throttle the best way to determine it's bad.

 

This the way most check to see if it is working but that does not mean it is bad either.
If it does do that then it is good and if does not you need to check it with an ohm meter.

1. Key off
2. IAC (ISC) solenoid disconnected
3. DVOM on 200 ohm scale
4. Measure solenoid resistance
5. The resistance should be between 7.0 and 13.0 ohms
If it is the coil is good and if not it is bad.
NOTE: Due to diode in the solenoid, place DVOM + lead on VPWR pin and - lead on IAC (ISC) pin.

DO NOT HOOK 12VDC to it or it will be bad as soon as you do!

 

Ok, 10.5vdc, it's good. I confirmed my connector off my wiring harness is good, my tps is good. The only question left is WTF?

Actually i left out something, when i did some tests earlier i had the connector disconnected with a string of connecting only the white wire to the iac. I started my truck and it idled at 600rpms. Don't ask.

Then when i pulled that wire off idle went up to about 850rpms. I reattached the connector, nothing happend, then pulled it back off and idle shot up a lil bit then dropped back to 850rpms. Connected the iac back up nothing happened. I did this twice, after that no results. Any ideas now.

 

Ok so since I determined that my IAC, TPS, and vacuum are all good i decided to check out the ECT

KOEO with the ECT disconnected the SIG RTN line puts out 4.6 vdc, which is strange since the TPS, IAC, and EGR all get exactly 5.0vDC. The ECT line read .15vDC just like the TPS, IAC, and EGR wires.

Next I back probed the harness connector with it still disconnected from the ECT and got the same readings. Strangely though when I back probe the connector with it attached to the ECT I get .77vdc on the SIG RTN and 0.0vdc on the ECT wire, same results when the engine hasn't been started all night, and when it's warm. I'm lost here.

I checked the resistance on the ECT with the engine cold-29K ohms. Which would imply 75*F coolant after it had been sitting all night. After the engine had warmed up plenty, temp gauge sitting at "O" in normal, I received a reading of 4.5k ohms ~ 167*. Of course those reading are implied with a VREF/SIG RTN of 5.0vdc.

During this however I was trying to bleed the coolant system in case there was an air pocket around the ECT. So I had the radiator cap off, and could see that there was coolant level changes. If i can see changes in coolant level then the thermostat would have to be open right? So i could have a bad thermostat that is screwing with my ECT provided it is supposed to be set to 192*F.

Even though I had proven to my self that the IAC was good in the ohm check and was getting and putting out the proper voltage, it still made no change in idle if it was plugged in or not. So I decided to try to get some results out of it. With everything connected KOER I disconnected the ECT and idle shot up to ~1700rpms. Then I disconnected the IAC idle dropped back down to 1k rpms, reconnected it & idle shot back up. Then reconnected the ECT and idle went back down. I did this several times with the same results.

I'm guessing that when the ECT is disconnected the ecu reads as the engine is cold and dumps more fuel which requires more area. So the ecu opens up the IAC. At least i'm Completely positive that the IAC is working now.

 

Do you still have the KOER code #13?