Weak pulse to injectors?

1989 FORD E-SERIES VAN
265,000 MILES • 5.8L • AUTOMATIC
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JOE21972
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Van will start if slight push on accelerator petal. With noid tester installed after a few seconds it lights very dimly. When pushing accelerator petal it brightens and van starts. Runs very poorly. If I keep feathering pedal every push noid brightens then dims again. Will not idle. Slows down and dies.

Fuel pressure is constant around 41 lbs. all injectors pass ohm test. Around 14.7 ohms. Wiring good from plug at front of engine.
Engine was recently rebuilt. Ran for a few days then problems. The icm failed. Ended up installing a new distributor and icm. Tried two eec. Same deal on both. Checked grounds all seem good. I don’t have a wire diagram or know what the PIN numbers are in the eec to test there.

If I spray fuel into the intake it runs good.
Also when running on the injectors it will not rev past about 1200 when feathering throttle. Dies if I just push throttle down and hold. Any ideas or directions?

Don’t know what I’m missing. Can get video of what it’s doing tomorrow
Aug 4, 2026 at 8:46 PM
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STRAILER
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Yes, please upload a video that will help. The light injector is a concern for sure, when cranking the pulse would be bright until the engine starts then it will calm down when at idle. Here are the wiring diagrams for the ICM and fuel injectors so you can test and see how the system works, but I need to say the fuel injectors can test well but then under load fail, please watch this video to tell you why.

https://youtu.be/2dYGZNaHpUA?si=lcaCBpGBRl3OGC0k

Also, I would try unplugging the MAP sensor to see if that helps, please let me know.
Aug 5, 2026 at 12:21 PM
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JOE21972
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Sent two videos. First is no throttle. Second is when I step on throttle. Noid brightens momentarily then goes back to dim and won’t run
Videos (Click to enlarge)
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Aug 5, 2026 at 12:24 PM
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JOE21972
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Ok I’ll try tonight when I get back home
Aug 5, 2026 at 12:25 PM
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STRAILER
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Okay, the pulse looks okay on the injectors, I don't think hat is an issue, is there a chance the catalytic converter is clogged? Does this van have one?
Aug 5, 2026 at 12:27 PM
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JOE21972
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Cat is not there
Aug 5, 2026 at 12:54 PM
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STRAILER
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Okay, you say it runs better on starting fluid correct? Have you changed out the fuel filter? I know it has 44 PSI but the filter can restrict the volume. Also, I would unplug the EGR valve. I also have seen the EGR stick open and cause on internal vacuum leak, here is a video to help you test it.


https://www.youtube.com/watch?v=DqUCbbKdWf4&t

Let me know how it goes.


Aug 6, 2026 at 5:35 PM
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JOE21972
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Yes new fuel filter

Unplugged map sensor. Will run now if slightly on throttle. Will get another map sensor. Still will not idle. After getting new map sensor I will check the timing again.
Aug 6, 2026 at 5:49 PM
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STRAILER
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Okay, please check the EGR valve as well.
Aug 6, 2026 at 6:29 PM
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JOE21972
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By unplugging it as well?
Aug 6, 2026 at 6:33 PM
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STRAILER
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I would do both unplug it and try, then remove it for the physical test to eliminate the possibility of causing the issue.
Aug 6, 2026 at 6:58 PM
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JOE21972
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Ok will try and let you know what it’s doing.
Aug 6, 2026 at 7:18 PM
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STRAILER
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Sounds good.
Aug 7, 2026 at 10:25 AM
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JOE21972
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Unplugged egr valve no difference. Removed it as well no difference. Timing may be off. Cannot get it to idle on its own. Will run with slight throttle pressure. Knocks or pings under acceleration. No load
Aug 7, 2026 at 10:57 AM
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JOE21972
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Will try to get new map sensor as well today
Aug 7, 2026 at 10:58 AM
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STRAILER
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Yep, I would check the timing as well, like I say a video of the how the engine is running is helpful.
Aug 8, 2026 at 7:45 AM
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JOE21972
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I will get to it today. I have a new map sensor now as well. Will send video later
Aug 8, 2026 at 7:48 AM
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JOE21972
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Sometimes runs good. Got the timing set again. Pings under load like timing is to far advanced. I removed dongle by distributor and set 10 degrees advanced. Shut off plugged dongle back in. Advances about 10 degrees more under acceleration. Then after running ok it starts to surge and then dies. Cranks like timing is to far advanced. Battery is weak. Right at end of attached video engine starts to surge. Got worse and died
Video (Click to enlarge)
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Aug 8, 2026 at 2:28 PM
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JOE21972
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Now cranks hard. Waiting for engine to cool back down and try again
Aug 8, 2026 at 2:31 PM
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STRAILER
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Hmm, I am wondering if the timing marks are off, also I have seen a vacuum leak made he engine surge like that and then stall. Here is a video to help us check for one.

https://www.youtube.com/watch?v=LRKWV4Are5c&t=3s

I know this style engine has many timing mark configurations so it can easily be off FYI.
Aug 10, 2026 at 10:49 AM
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JOE21972
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Yes. I am going to go through the timing again today. I learned a bit more about the timing. I also got a new timing light that has the advance ability built in. Digital. I believe I am not doing it correctly. Will see if I can figure it out. Also will check for vacuum leaks as well. Thank you for all the help so far. With your help I’ll get it figured out
Aug 10, 2026 at 10:53 AM
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STRAILER
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Yep, that is what I like about car repair, not matter what we can fix it, unlike humans, lol
Aug 10, 2026 at 10:58 AM
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JOE21972
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Hahahaha. Yeah I don’t want to talk about repairing humans.
Aug 10, 2026 at 10:59 AM
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STRAILER
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yep, no fun, car are much better lol
Aug 11, 2026 at 7:01 AM
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JOE21972
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Could a weak battery cause surging at idle? Went through the timing and got it set. Ran good in shop. Put air cleaner on and charged air conditioning. Engine started surging at idle. Had no vacuum leaks when checked. Will check again. But van randomly turns hard when warm. Could be the battery.
Aug 13, 2026 at 3:41 PM
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JOE21972
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No vacuum leaks. Randomly won’t turn over. Like a vapour lock on a heavily advanced motor but is set at 10 degrees with spout out. With spout in Goes to about 15 degrees when idling and about 32 degrees under throttle. Sometimes idles good. Waiting for it to cool down now to see what happens when cold. I may retard the timing slightly as well to see if that changes things as well
Aug 13, 2026 at 6:27 PM
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STRAILER
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Yep, that is what I was going to advise, back the timing down to see if it does better, it could be the timing of the camshaft is off as well. To check that the valve cover must be removed on the passengers side. Also, are you able to drive it at all, and if so does it ping?
Aug 14, 2026 at 9:34 AM
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JOE21972
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I’m going away for two weeks. Will have to deal with it when I get back. New plugs wires cap rotor distributor coil. Seems a bit short on power as well but will drive down the road ok. Idles good most of the time. Randomly will surge like it has a huge cam in it. Which it does not. Good compression good oil pressure. All injectors test good. Spray test good ohm resistance at 14.5. May have a slight exhaust leak. Will look into it when I get back.
Aug 14, 2026 at 10:39 AM
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JOE21972
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Only way cam if off is if the timing marks are incorrect. Also has a new timing gears and chain.
Aug 14, 2026 at 10:40 AM
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STRAILER
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Yep, the exhaust leak can cause the oxygen sensor to get fooled which will cause the idle issue so that is something I would look into when you get back, have a nice time away, see you you get back.
Aug 14, 2026 at 6:14 PM
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