'89 F150 idle problem
RSS | Subscribe | Contact Us | Advertise | About Us
Page 1 of 2 12 LastLast
Results 1 to 25 of 36
  1. #1
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    '89 F150 idle problem

    Same old beast as my thread from over a year ago or so.

    '89 with inline 6 and 4 speed. It's also red.

    The exhaust smell will peel paint, make eyes water and make a person puke or die.
    I can still taste it from plowing yesterday.

    Starts cold like a champ, barely even turns over and it's running at -10 F.

    It surges and works its way down to dying.

    Yesterday I cleaned the idle air control valve, but it wasn't really dirty. It also had correct ohm reading.
    Throttle position sensor - Correct ohm reading through full sweep.
    Replaced engine temp sensor

    I'm thinking EGR problem?

    Anyone have a thought on this wicked cool ride?
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  2. #2
    Join Date
    Nov 2005
    Location
    Nashville, TN
    Posts
    2,928

    Re: '89 F150 idle problem

    Fuel pump? How many does it have. But thanks, I don't feel so crazy. Just gave my 88 f150, 5.0l to my son. 300k. Very nice ride, he is not of the same opinion. So I suspect it will be gone when he can save some money.

  3. #3
    Join Date
    Dec 2016
    Location
    San Antonio Valley Peoples Republic of California
    Posts
    71

    Re: '89 F150 idle problem

    Sounds like it's going rich. Check the O2 sensor or that the fuel pressure regulator isn't stuck.
    So many projects, so little time,,,

  4. #4
    Join Date
    Mar 2016
    Location
    North Georgia
    Posts
    1,959

    Re: '89 F150 idle problem

    I've seen a few where in cold weather the oil thickens up and it'll overload the roll pin on the distributer and it'll shear the pin. Most the time they'll spin enough to make them not run though..I seen 1 that just sheared and twisted a few degrees.
    Sounds like timing or map sensor problem. I'd check the vacuum line to the map. Map sensor is on the heater box I think

  5. #5
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Quote Originally Posted by john chamorro View Post
    Sounds like it's going rich. Check the O2 sensor or that the fuel pressure regulator isn't stuck.
    It is rich for sure. After its warmed up and shut off for a few minutes, I have to hold the pedal on the floor to start it - and its fuel injected.

    Maybe I better put the pressure tester gauge on it tomorrow and see what it reads.

    Haven't looked in a long time, but that should be after the regulator right?
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  6. #6
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Quote Originally Posted by Michael ray View Post
    I've seen a few where in cold weather the oil thickens up and it'll overload the roll pin on the distributer and it'll shear the pin. Most the time they'll spin enough to make them not run though..I seen 1 that just sheared and twisted a few degrees.
    Sounds like timing or map sensor problem. I'd check the vacuum line to the map. Map sensor is on the heater box I think
    I don't have a meter with Hz reading capability. But if I unplug the MAP sensor vacuum line, and hook my vacuum pump to it, I should be able to verify operation by running through the vacuum range and seeing if the idle smooths out right?
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  7. #7
    Join Date
    Nov 2009
    Location
    Arizona
    Posts
    1,948

    Re: '89 F150 idle problem

    Quote Originally Posted by MinnesotaDave View Post

    It surges and works its way down to dying.

    :
    Wouldn't a serious vacuum leak cause this? 02 sensor sees lean and drives mixture rich (hence the stink) till it stalls. It's been some time since I worked on one that old and I don't remember exactly how but can't you read the codes with a paper clip? I remember doing that on an eighty something Oldsmobile. I'll bet the IAC is all the way rich. Curious to see how this turns out.
    Miller Challenger 172
    Miller Thunderbolt AC/DC 225/150
    Miller Maxstar 150 STL
    Victor 100C
    Victor Journeyman
    Oxweld OA
    Harris O/A
    Smith O/A little torch

    No, that's not my car.

  8. #8
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Quote Originally Posted by bigb View Post
    Wouldn't a serious vacuum leak cause this? 02 sensor sees lean and drives mixture rich (hence the stink) till it stalls. It's been some time since I worked on one that old and I don't remember exactly how but can't you read the codes with a paper clip? I remember doing that on an eighty something Oldsmobile. I'll bet the IAC is all the way rich. Curious to see how this turns out.
    Hmmm, could be right. While idling I unplugged the IAC and it instantly died.
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  9. #9
    Join Date
    Sep 2008
    Posts
    153

    Re: '89 F150 idle problem

    My bets are on a truck that old- as has been mentioned check the fuel pressure regulator, But I am betting a leaking pintle valve in an injector if it is direct injected or the injector on the TBI if it has throttle body. The surging is probably due to the O2 sensor trying to lean it out and it can't shut off the fuel completely. The fact you stated it is hard to start after shutting it off for a few minutes indicates fuel is leaking into the cylinders and flooding it. All the other causes wouldn't do that since with no power the injector(s) should be in default off position and some how you are getting fuel into cylinders after shutdown. Leaking injector will do that.

  10. #10
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Ok, so then if I hook the gauge for fuel pressure - I should be able to turn off the key and see how long it holds pressure I'm guessing.

    Been many years since I did this as part of my jobs, so I'm going from dusty memory on some of it
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  11. #11
    Join Date
    Sep 2008
    Posts
    153

    Re: '89 F150 idle problem

    Does it have direct injection or TBI? If direct you can unplug each injector one at a time kind of like pulling a plug wire off- if you have a leaking injector when you disconnect it rpm shouldn't drop if it is leaking. If TBI- you have to take the injector out and check Youtube for how to clean injectors-you can use the same method to test to see if it is leaking.
    That is an OBD1 setup- you can 'read' the codes with a VOM after you jumper the appropriate pins in the test plug. Been too long to take it from memory but I can look in the AM for the pins. You count the swings of the needle for your codes and somewhere I should have the chart to decode or Google them. Yes on the gauge dropping.
    Last edited by 131re; 01-11-2017 at 11:59 PM.

  12. #12
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    I have the jumper instructions and chart for codes in my old book, so no need to dig for them

    Check engine light is not on - which is weird in my opinion.
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  13. #13
    Join Date
    Mar 2015
    Posts
    39

    Re: '89 F150 idle problem

    try taking vacum line off fuel pressure regulator.could have a bad diaphram leaking fuel into vacum line.

  14. #14
    Join Date
    Sep 2008
    Posts
    153

    Re: '89 F150 idle problem

    Not that weird-that is as I said OBD1 and the computers were not as sophisticated as OBD2 is. If the sensors are all giving good signals no MIL Lamp lit. Which then makes it all the more likely it is 'mechanical' is in leaking injector or leaky regulator. One would think that the O2 signal would be in error but I have seen engines really rich and the O2 sensor oblivious to the fact when it is a mechanical leak. Or maybe your check engine light is burned out and jumpering test port will show the code. Forgot if it never goes into closed loop mode- code will not be set. So if temp sensor was keeping it from going into closed loop or your 'balmy temps' In MN keep the engine cold enough-until it goes into closed loop no codes.
    Stupid question- dont' know how long this has been going on for you, but have you recently replaced the thermostat or if the problem goes back aways was the 'stat replaced any time prior to the issue?
    Last edited by 131re; 01-12-2017 at 12:58 AM.

  15. #15
    Join Date
    Nov 2015
    Location
    Beacon and Pawling, New York
    Posts
    1,014

    Re: '89 F150 idle problem

    See if you can view sensor data. My buddy had a Dakota that did something similar. Turned out to be a bad temperature sensor. The computer thought it was 150 degrees below zero! It was trying like hell to get it to warm up.
    Last edited by Sedanman; 01-12-2017 at 06:04 AM.
    Eventual master of the obvious, practitioner of "stream of consciousness fabrication". P.S. I edit almost every post because because I'm posting from my phone and my fingers sometimes move faster than my brain.

  16. #16
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Quote Originally Posted by ram69 View Post
    try taking vacum line off fuel pressure regulator.could have a bad diaphram leaking fuel into vacum line.
    Yep, going to do that one too - I had that happen on a car once.

    Quote Originally Posted by 131re View Post
    Not that weird-that is as I said OBD1 and the computers were not as sophisticated as OBD2 is. If the sensors are all giving good signals no MIL Lamp lit. Which then makes it all the more likely it is 'mechanical' is in leaking injector or leaky regulator. One would think that the O2 signal would be in error but I have seen engines really rich and the O2 sensor oblivious to the fact when it is a mechanical leak. Or maybe your check engine light is burned out and jumpering test port will show the code. Forgot if it never goes into closed loop mode- code will not be set. So if temp sensor was keeping it from going into closed loop or your 'balmy temps' In MN keep the engine cold enough-until it goes into closed loop no codes.
    Stupid question- dont' know how long this has been going on for you, but have you recently replaced the thermostat or if the problem goes back aways was the 'stat replaced any time prior to the issue?
    This has been an ongoing problem. But since I only plow with it, and almost never drive it otherwise, it's been ignored since it was still running good enough to plow. But now it's gotten worse and dying too much - have to keep my foot on the throttle while working brake and clutch with left foot.

    Quote Originally Posted by Sedanman View Post
    See if you can view sensor data. My buddy had a Dakota that did something similar. Turned out to be a bad temperature sensor. The computer thought it was 150 degrees below zero! It was trying like hell to get it to warm up.
    Too old to view sensor data a but I did replace temp sensor since it was easy and cheap - no fix unfortunately.

    I'm really thinking the guys are right about injector leak or bad regulator. Starts perfect and super quick even below zero - then goes downhill pretty quickly.

    Supposed to be -30 degF tonight, so I may not get to work on it until Friday night.
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  17. #17
    Join Date
    Dec 2008
    Location
    Lockhart,Tx (BBQ capitol of the world)
    Posts
    431

    Re: '89 F150 idle problem

    Quote Originally Posted by ram69 View Post
    try taking vacum line off fuel pressure regulator.could have a bad diaphram leaking fuel into vacum line.
    This is my bet also!
    I had a '94 ford Tempo that did the same thing. It would start great but if left to idle for more than a minute the idle speed would slowly drop and then die.
    If you shut off the engine and pull the vacuum line going to the fuel pressure regulator you will see fuel start to drip out of the regulator fitting after a few minutes. The vacuum line going to the fuel pressure regulator will need to be replaced also.
    Last edited by rexcormack; 01-12-2017 at 09:35 AM.

  18. #18
    Join Date
    Nov 2015
    Location
    Beacon and Pawling, New York
    Posts
    1,014

    Re: '89 F150 idle problem

    Is there an air temperature sensor?
    Eventual master of the obvious, practitioner of "stream of consciousness fabrication". P.S. I edit almost every post because because I'm posting from my phone and my fingers sometimes move faster than my brain.

  19. #19
    Join Date
    Nov 2009
    Location
    Arizona
    Posts
    1,948

    Re: '89 F150 idle problem

    Actually a leaking diaphragm makes a lot of sense, more so than a vacuum leak. Pull the vacuum line just after shutdown to see if it's wet.
    Miller Challenger 172
    Miller Thunderbolt AC/DC 225/150
    Miller Maxstar 150 STL
    Victor 100C
    Victor Journeyman
    Oxweld OA
    Harris O/A
    Smith O/A little torch

    No, that's not my car.

  20. #20
    Join Date
    Nov 2005
    Location
    Nashville, TN
    Posts
    2,928

    Re: '89 F150 idle problem

    Got a tfi module? Test that. It has been a while, however it recall a symptom similar to yours . Though I suspect mine died after warming up and overheating the module, not much warming up where you are?

  21. #21
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Quote Originally Posted by Sedanman View Post
    Is there an air temperature sensor?
    I do not recall if the 89 inline 6 has one or not. I'll be sure to check.

    Quote Originally Posted by tapwelder View Post
    Got a tfi module? Test that. It has been a while, however it recall a symptom similar to yours . Though I suspect mine died after warming up and overheating the module, not much warming up where you are?
    The ignition module and coil had to be replaced last time when it stopped running.

    That was also a thread on here

    It's looking like fuel regulator or injectors is winning the theories so far - I'll be sure to have an answer by Friday or Sunday.
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

  22. #22
    Join Date
    Nov 2012
    Posts
    564

    Re: '89 F150 idle problem

    Quote Originally Posted by MinnesotaDave View Post
    Same old beast as my thread from over a year ago or so.

    '89 with inline 6 and 4 speed. It's also red.

    The exhaust smell will peel paint, make eyes water and make a person puke or die.
    I can still taste it from plowing yesterday.

    Starts cold like a champ, barely even turns over and it's running at -10 F.

    It surges and works its way down to dying.

    Yesterday I cleaned the idle air control valve, but it wasn't really dirty. It also had correct ohm reading.
    Throttle position sensor - Correct ohm reading through full sweep.
    Replaced engine temp sensor

    I'm thinking EGR problem?

    Anyone have a thought on this wicked cool ride?

    Does that one use a timing belt or chain or gears? My experience with a lot of OLD cars is that the timing chain stretches and the valve opening is delayed and that causes that really ACRID exhaust that will bring tears to your eyes. How many miles since that timing ????? was replaced?

  23. #23
    Join Date
    Mar 2016
    Location
    North Georgia
    Posts
    1,959

    Re: '89 F150 idle problem

    Had a 90 model that was towed in today.
    It wasn't firing the injectors. Turned out to be the map sensor

  24. #24
    Join Date
    Nov 2009
    Location
    Arizona
    Posts
    1,948

    Re: '89 F150 idle problem

    Quote Originally Posted by MinnesotaDave View Post

    Supposed to be -30 degF tonight, so I may not get to work on it until Friday night.
    Hard to imagine, I don't think I could take that. Been near 70 every day here and only getting down in the 40's at night. I forget how it is in other places and how lucky we are, the weather rarely affects what we plan to do from day to day.
    Miller Challenger 172
    Miller Thunderbolt AC/DC 225/150
    Miller Maxstar 150 STL
    Victor 100C
    Victor Journeyman
    Oxweld OA
    Harris O/A
    Smith O/A little torch

    No, that's not my car.

  25. #25
    Join Date
    Jun 2012
    Location
    Bemidji MN
    Posts
    12,724

    Re: '89 F150 idle problem

    Quote Originally Posted by Sedanman View Post
    Is there an air temperature sensor?
    It does have an intake air temp sensor.

    Quote Originally Posted by FlaJoe View Post
    Does that one use a timing belt or chain or gears? My experience with a lot of OLD cars is that the timing chain stretches and the valve opening is delayed and that causes that really ACRID exhaust that will bring tears to your eyes. How many miles since that timing ????? was replaced?
    Timing gears on this 4.9 inline 6.
    Dave J.

    Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

    Airco 300 - Syncro 350
    Invertec v250-s
    Thermal Arc 161 and 300
    MM210
    Dialarc
    Tried being normal once, didn't take....I think it was a Tuesday.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement