aaronrodgers38

Driving along in 89 f150 5.8lw today on the highway at about 65mph I have no cat, basically straightpipe. heard 3 LOUD backfires as all my lights came on in my dash. coasted truck to the shoulder. truck is now safe at home after a AAA tow. Engine will idle but when I press gas pedal, absolutely no needle movement on RPM gauge. if I hold pedal down, truck dies. checked to make sure linkages and cables were still attached, they were. on my distributor there was one spark plug wire that wasn't fully seated onto the cap lobe. Thought maybe timing was shifted. removed spout after engine was warm, and the engine wont stay running long enough with the spout connector disconnected for me to check the timing. Gas is below 1/4 of a tank but I do not suspect it to be fuel related? I changed fuel filter/pump under 2 months ago. Please Help. Havent read anything that sounds similar to my problem so im unsure of where to start. I pulled codes and got 33 for KOEO and 12,22,13,72 for KOER test. which translates 13: Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high) 12: Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) – ISC 22:MAP (vacuum) or BARO signal out of range – MAP 72: No MAP or MAF change in “goose” test – retest, check for frequency or voltage change – MAP MAF. Going to get fuel pressure tester tomorrow but if anyone has any other insight would be greatly appreciated. thank you.

aaronrodgers38

replaced IAC and MAP still pulling 12/13/22 codes after replacement. engine runs the same

Bigmule

My 93 5.0 did the same thing and it wound up being the tps !

aaronrodgers38

i was going to go after that tomorrow, some others have told me the tps but i was chasing what i had in the codes first. havent seen a code for the tps but i guess ill throw one in to see if that can be the fix. if its not i really have no idea whats going on under the hood. Thanks for the reply. ill let you know the outcome tomorrow.

aaronrodgers38

Tested fuel pressure. Reading 38 psi during cranking.

Chris_1

iTrader: (1)

You measure it Key On Engine Off, then idle then slight acceleration.

aaronrodgers38

cant get it to idle when tester is installed. so all i got is cranking pressure. KOER codes are 12/22. already changed map sensor.

aaronrodgers38

checked to see what timing was at. couldnt get it to idle with spout disconnected. so while it was cranking i checked timing and it was firing at about 0 degrees. i had previously had it set at 12 degrees. and on initial inspection i tried moving my dizzy by hand and wouldnt move what so ever. unsure as to what would cause my timing to jump 12 degrees while the distributor was securely tightened down. thanks for feedback and responses i appreciate it.

Chris_1

iTrader: (1)

Wonder if maybe your timing chain jumped a tooth ?

aaronrodgers38

yeah either harmonic balancer may have slipped in the key way. or the timing chain guides broke, tooth broke. has 110k on it . still haven't totally ruled out fuel issue with tank pump cause I read 40-45 psi for 351's but again the 38 psi I got was only when cranking. couldn't get it to idle with tester installed for some reason. but if I am able to reset my timing today and it gets fixed, then that's what im going to assume it is. if I get it set and still no throttle. im thinking its going to be fuel.