When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The PIP wire should have 6 VAC on it.
The PIP either will work or not.
It can work then when the engine gets hot it shut you down like turning off the key.
When the engine cools back down it will restart most of the time.
maybe i didn't replace the pickup. i replaced the distributer cap. also, i did the computer test like 20 times over the last couple of weeks, i definately have the code 12 and 65.
12 says that you may have a bad IAC Valve.
65 says you did not press the OD Switch when you should have.
65 indicates that Overdrive Cancel Switch (OCS) is not cycled between the engine ID code and the "Goose Test" in Key One Engine Running Self-Test.
Sorry if I miss lead you I must not have read the text right before.
maybe i did do the test wrong. what your saying is when i goose it, i should also press the o/d switch. i didn't do this. i have cleaned and swapped out the IAB, but i am still getting this code 12
Service Code 12 indicates that during Engine Running Self-Test, engine rpm could not be controlled within the Self-Test upper limit band.
Possible causes:
Open or shorted circuit
Throttle linkage binding
Improper idle airflow set
Throttle body/ISC solenoid contamination
Items external to Idle Speed Control system that could affect engine rpm.
Damaged ISC solenoid
Damaged processor
ok, i checked the voltage at the iab wires, it measured good. i will check the idle air, isc solenoid and get back on here tommorow. by damaged processor, do you mean the computer?
thanks, maybe i am getting somewhere, i have been quite stalled.
ok, i checked the voltage at the iab wires, it measured good. i will check the idle air, isc solenoid and get back on here tommorow. by damaged processor, do you mean the computer?
thanks, maybe i am getting somewhere, i have been quite stalled.
Yes the computer is what it said and again that was from the Ford Shop Manual.
I would not change it until I had more proof of it being bad but it may be bad.
I am comfused by the ISC (Idle speed control), i'm not sure what it is. Is this the BYP valve on EFI, or is it something else? about where is it located and what does it look like, i'm not finding much about it in my book.
thank,
Brian
89 5.8
new today 91 straight 6 with 4 speed manual!
I am comfused by the ISC (Idle speed control), i'm not sure what it is. Is this the BYP valve on EFI, or is it something else? about where is it located and what does it look like, i'm not finding much about it in my book.
thank,
Brian
89 5.8
new today 91 straight 6 with 4 speed manual!
Yes it is the bypass valve (IAC valve) on the side of the throttle body.
ok, i've swapped this out with no change. this leads me to think maybe there is something wrong with the computer. the only other thing would be to adjust the idle speed, but i wasn't sure this affected how it would run when driving. am i wrong? it idle's fine. when you first start it, it idle's fast for just a few seconds, then drops down to a slow idle.
I really dough that there is anything wrong with the computer but it was just in the check list from shop manual for code #12.
When it did the KOER test did the engine got higher rpm and then back down while the test was running?
Did it sound OK?
It is possible that you may have a bad TPS, I think I would check it with a DVM to see if it has the right voltage output to the computer through its range.
I have an 89 5.0 with the same problem and I replaced the MAP sensor and a Ford tech told me to replace the fuel regulator...it seems mine back fires and pops when cold not as bad when hot...? not sure.. but I am replacing the regulator tomorrow will post up to see if that works...side note....my front fuel tanks reads past full even though empty and the rear reads empty when full???? I also wondered if this could be computer gone bad...or just crummy pump
moe you could possibly have a bad computer or more likely wiring or fuel pump sending unit. id wait for subfords response though. from what ive seen he knows just about everything about the electronics in these trucks, very well read