1990 4.9 run ability issue
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4wd Low
Joined: Dec 2021
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1990 4.9 run ability issue
Hello, I been trying to figure out my 1990 e 150 with 4.9. This is what is going on. It will start rite up but runs as its running rich and rough, after awhile idle jumps high but still running rough. then decides to drop idle after awhile. I pulled all plugs that I installed few months back and all the plugs were carboned up. This this what I have done since. Clean Plugs
replaced, TPS, Idle control valve, EGR valve as old one was leaking, Temp sensor, fuel filter, new distributor since it came with Ignition control module, cap and rotor, New Coil .Pulled and cleaned Throttle body.
Fuel pressure first cycle 0 psi 2nd about 10 psi 3rd bout 30 psi up to 40 psi. With engine running its at 50 psi, when I unplug the FPR idle jumps up to 55 psi. I've searched for vacuum leaks but none found that would make a difference..
Any ideas where or what to look at next? Any help would be greatly appreciated
replaced, TPS, Idle control valve, EGR valve as old one was leaking, Temp sensor, fuel filter, new distributor since it came with Ignition control module, cap and rotor, New Coil .Pulled and cleaned Throttle body.
Fuel pressure first cycle 0 psi 2nd about 10 psi 3rd bout 30 psi up to 40 psi. With engine running its at 50 psi, when I unplug the FPR idle jumps up to 55 psi. I've searched for vacuum leaks but none found that would make a difference..
Any ideas where or what to look at next? Any help would be greatly appreciated
Fleet Mechanic
Joined: Nov 2002
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Mountain Pass
Joined: Nov 2021
Posts: 179
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From: South MS
Merry Christmas!
I’d recommend trying to see codes your computer is showing first. And with some of what you’re describing, also checking your ignition timing …
there are a number of posts on here and other Ford forum sites on how to pull/read codes.
There should be good instructions on your under hood label (the same one that shows your vacuum hose routing) on how to check timing. Do you have a timing light?
I’d recommend trying to see codes your computer is showing first. And with some of what you’re describing, also checking your ignition timing …
there are a number of posts on here and other Ford forum sites on how to pull/read codes.
There should be good instructions on your under hood label (the same one that shows your vacuum hose routing) on how to check timing. Do you have a timing light?
Hotshot
Joined: Jul 2020
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From: Near Salt Lake City
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4wd Low
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Hi Sorry for just getting back, I was in the hospital since Christmas and just got home. I Order an OBD1 reading since it would not allow me to read the codes by blinks, I just got it in but won' t be able to touch it for couple weeks. had surgery and pretty much laid up. I'm hoping to get codes when I get out to the shop. Thanks for replies
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4wd Low
Joined: Dec 2021
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I couldn't wait and had my grandson help me hook up OBD1 scanner. I get no codes what so ever. So I'm back to suggestions. I won't be able to work on it for at least 3 weeks when I heal up. I'll keep reading and researching
Hotshot
Joined: Jul 2020
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From: Near Salt Lake City
Fuel pressure problems seldom set codes
Same with the ignition system on that old 1990 (no IDM monitor or related codes for that)
You really getting 11-10-11 or just no codes outputted?
You need to run the key on engine off test and key on engine running test where you activate the boo switch and TCS or clutch etc.(KOEO and KOER)
You did all that?
Same with the ignition system on that old 1990 (no IDM monitor or related codes for that)
You really getting 11-10-11 or just no codes outputted?
You need to run the key on engine off test and key on engine running test where you activate the boo switch and TCS or clutch etc.(KOEO and KOER)
You did all that?
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4wd Low
Joined: Dec 2021
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I've done the test yesterday but got no codes what so ever. I hooked up tester ,turned key on and no codes. did it twice.. I bought the Ford OBD1 tester but not getting anything. I did not try starting it up with tester hooked up. but will try that today. I will try dryer in tank when I can. just moving slow till I heel up.
Thanks for input.
Thanks for input.
Hotshot
Joined: Jul 2020
Posts: 10,377
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From: Near Salt Lake City
The scan tool needs to display 11-10-11 for you, in order for you to know you have no codes
Otherwise you have a no codes outputted condition
And that sends you down a different sub routine for the diagnostics
I am only used to the Ford scan tools Star tester and NGS new generation star, those are the ones I have
Those tools both prompt you to initiate the test sequence by seeing the BOO switch operate and the TCS solenoid or clutch. a brief WOT
Yours should do the same? Maybe
Otherwise you have a no codes outputted condition
And that sends you down a different sub routine for the diagnostics
I am only used to the Ford scan tools Star tester and NGS new generation star, those are the ones I have
Those tools both prompt you to initiate the test sequence by seeing the BOO switch operate and the TCS solenoid or clutch. a brief WOT
Yours should do the same? Maybe