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. Thank you.

 

How many miles on engine? Does the CEL come on when trying to start or idling.
You can still pull the KOEO test and get codes if any. Maybe she jumped time has happened not often but it does. Fuel pressure test can borrow the gauge from Autozone or the like.

 

If your tach isn't registering anything, your pip inside the distributor is likely bad.

Pull codes.

 

Will pull codes and CEL light is off. about 150k miles I believe Thanks for response.

 

Ok, so i pulled some codes. KOEO codes came back as 11, 21, 22, 33. When i did the running test. engine ran like it did before it broke down. made me miss it a whole lot. pulled codes 12,21,22,23 as long as i read and understood it right. as soon as i pulled out my jumper wire for the self test. truck returned to its post broken down state of dismay.

 

ran test again with engine on got code 82/83

 

Code 11 (assume this was from KOEO tests): System Pass

Code 21 (assume from CM): ECT out of self test range 0.3 to 3.7 volts.
Code 22 (assume from CM): MAP sensor out of self test range.
Code 23 (assume from CM): Closed throttle TPS voltage higher or lower than expected.

Code 21 from CM indicates the ECT sensor has been out of range during operation.

Code 22 from CM indicates the MAP sensor has been out of range during operation.

Code 23 from CM indicates the TPS has been out of range during operation.

This is why it's important to know when the codes were displayed. If those codes were from the KOEO tests that means those sensors are currently out of range.

Based on your symptoms I would suspect the MAP sensor may be bad. Same for the TPS. It would be beneficial to know when those codes were displayed to determine if the codes are intermittent or failing the KOEO tests real time.

 

KOEO codes came back as 11, 21, 22, 33
KOER codes 12,21,22,23, 72


also CEL light no illuminated when engine idling while im trying to troubleshoot. can pull throttle lever on throttle body slowly to make engine rev. if I hold it WOT it dies just like it would if I was on the gas pedal.

 

There are two parts to the KOEO tests and stored code (CM) display. The first set of flashes/codes are the results from the KOEO tests. If there are no test failures you will get Code 11 System Pass.

Then there is a separator flash to indicate any stored codes will be displayed next. If there are no stored codes you will get Code 11 System Pass again. It's imperative to know when the flashes/codes were displayed. They can and frequently do have different definitions based on when the flashes/codes were displayed.



There is no reason to try to make the CEL come on, if there are any failures during operation the code(s) will be stored in memory, aka CM (Continuous Memory).



If the engine is not fully warmed up before running the KOEO or KOER tests you can falsely trigger Code 21.

Since you have Codes 22 and 23 in KOEO/CM and KOER it's safe to assume both could be faulty.

Verify there is a vacuum hose attached to the MAP sensor. Also verify it's connected. If you have a meter than can measure frequency, verify the output.

Verify the TPS output with a voltmeter. If it is higher or lower than 0.6-10VDC, replace it.

 

so i disconnected my battery for the night. cleared all memory. let truck warm this morning. KOEO got two 11's. KOER i got code 12,13,21,22. while i was warming engine up. made sure vacuum hoses i could see were intact and connected where need be. checked fuel pressure regulator for fuel and suction. no fuel smell and great suction from vacuum. as expected. MAP sensor is connected and vacuum is connected. terminals for connector look clean aswell. So problems i have recurring according to codes per KOER are 12/13/21/22. could all three sensors be causing my problem, as in should i go buy all three sensors or one at a time? also i was able to inch it forward when put in drive via gas pedal. something i was unable to do yesterdday. but when i say inch. i litterally mean inch. bearly gave me anything with WOT. I appreciate you keeping up and helping me out with this.

 

so i replaced IAC and MAP sensors. both seperatly and checked KOER each time. code 12/13/22 are still reading. runs the same.

 

Very odd Code 22 does not show up in the KOEO tests. Verify the electrical connections are tight and clean.. If the vacuum hose is original/suspect..replace it.

Code 12 & 13 indicate the computer cannot sense/control the idle RPM. Could be a vacuum leak.

If the truck is still not able to move under it's own power check the fuel pressure.

Given your symptoms it's highly advised to pull out the computer (PCM) then inspect it for signs of leaking capacitors and/or burned components.

 

Tested fuel pressure today, read at 38 psi while engine cranking. although could only crank today no idle. little cooler today due to rain but i live in hawaii so only about 5 degrees below 70. PCM checked out no burn capacitors and solders look good. checked fuses for the hell of it and all good. KOEO fuel pressure read at a little over 8 psi.

 

So it looks like the fuel pressure is dropping pretty quickly. 38 PSI while cranking is reasonably good. The fact you still have Code 22 is problematic. That means the computer is still not getting a good MAP signal. Tracing the wires may be in order.

Hawaii, eh? I recall a thread a few years ago from someone who lived in Hawaii. Their truck would not run even though they had good fuel pressure, injector pulses and good spark (after some repair work). After weeks of troubleshooting and some prodding, they siphoned the fuel tank then poured in 5 gallons of fresh fuel. The problem was resolved by doing just that.

Perhaps lightning strikes twice

 

So why did you replace the IAC? You have a code for the TPS. Have you picked up a multimeter and checked sensor? If the computer doesn't know the throttle position how is expected to properly operate the IAC?