89 F150 302 A0D 2WD

KOEO:
81 Air Managmenr 2 Circuit Malfunction
82 Air Managmenr 1 Circuit Malfunction

KOER:
12 Cannot Control RPM During Self-Test High RPM Check
41 HO2S (sensor) System Lean Right Side
13 Cannot Control RPM During Self-Test Low RPM Check
25 Dyn Response Test Knock Sensor Not Detected

the truck does not stay running anymore. it starts right up after it's sat for a while. still idles high as hell and when the temp gauge gets to around 180 degrees (it has an aftermarket A-Pillar temp gauge) the motor starts to stumble and finally dies. then it's hard to start back up afterwards and even if it does start again it will die.

i flushed out the cooling system cuz the upper rad hose was really hot and stiff yet the bottom hose was only slightly warm. i thougth there might be a clog somewhere. but i blasted a hose through the system until it all came out clear. flow is verified through the radiator as i flushed it from both directions along with the block. i did not replace the t-stat.

after i did this the truck still died.

i checked all of the vacuum lines on the motor and there isn't anything that leaks; EXCEPT the EGR solenoid. i tested the whole EGR vac system plugging the vac pump at the vac source and pumped the air out. i heard hissing noises coming from the solenoid. this was with the motor off and everything off. i tested the line going to the solenoid and it's fine. i tested the line going from the solenoid to the EGR valve and it's fine. the egr valve also hold vac. do i need a new solenoid?

and what's up with those codes? what do i check for to fix them?

 

I'd suspect at least two faults (probably more):

1) IAC valve - it controls idle speed. Try cracking the throttle a bit to see if the engine starts/runs. They're notorious for getting sticky. You can try cleaning it by removing it and using some intake/ TB cleaner in it.

2) EVR solenoid - should not pass any vacuum at all except under PCM control. If it does, you'll get EGR flow at the wrong time which can mask IAC function, cause mixture problems, and more.

As for the coling system, a couple of ideas come to mind. Replace the thermostat, first off. I'd be worried about about the water pump and be on the lookout for a leaky head gasket.

Good luck.

Steve

 

ok, fixed the lean running condition. i have dual fuel tanks and the rear one was on empty. dropped 5 gallons of gas and it doesn't stall out or die anymore. we can call that operator error...:o but it still idles high.

replacing the IAC with a new one did not work. there goes 60 bucks. last ditch effort for me was to spray the TB and upper intake manifold mating flanges and the idle started to fluxuate. i sprayed a bunch more and the motor was about to die.

yippee, wish me luck on a new TB gasket. what's that around 5 bucks? this thing's been kicking my *** for the last couple months and it might only be a bad TB gasket.

 

ok, so replacing the TB gasket did nothing. the old one was pretty messed up. i'm gonna have to start tearing apart the intake manifold now. this is getting ridiculous.

plus it's extremely difficult to use brake cleaner when the truck has a solid mounted fan. all the brake cleaner i spray at the joints and connections BLOW AWAY or dry up before it even makes the motor stumble. even more so when the truck is up to temp and it blows HOT AIR IN MY FACE.

 

Take the accessory drive belt off while you look for the vacuum leak. It can run for a few minutes that way without any ill effects.

 

i'll try that. i'll probaly go through a couple batteries searching for the leak knowing my luck.

 

ok so i looked over the truck today and i still haven't found it.

i did notice that between the intake runners of 6 and 7 there is a tapped hole on the lower intake manifold (driver's side). there is nothing that is bolted into this hole. there are 2 floating connectors nearby that isn't plugged into anything also.

is this where the knock sensor is supposed to be hooked up at? would this explain the no knock sensor detected code? and does this hole lead all the way through into the air intake?

 

i notice a 1 inch spacer bolted in between the upper and lower intake manifold. the FSM does not show a spacer in between these manifolds. is this supposed to be there?

 

It's an aftermarket part. It's a phenolic riser which reduces the heat added to the incoming air charge and lowers the powerband by a few RPM. Check to make sure there are intact gaskets both above and below and that all your upper to lower manifild bolts are torqued to 12-18 ft-lbs.

 

would a loose valve cover contribute to a vacuum leak through the PCV valve? one or both of them have their bolts loose.

also the bolt closest to the TB housing that holds down the lower intake mani broke off. i tried extracting it but the stupid extractor broke off into it so now i can't drill into it. what to do?