Ol red is ashakin
Thread Starter
Junior Member
Joined: Aug 2017
Posts: 23
Likes: 3
Ol red is ashakin
Hey guys, new to forums and to Ford's. Well new to any trucks. I was a city boy (trains, buses, walking and skateboards, until the south called and i picked up this baby at the auction for 500$ about 3 weeks ago.
It was running awesome. Never been in a truck with so much down low.
Well anyway, troubles started earlier this week. I caught my wife running around on me and has been pretty hectic and fuzzy ever since.
1987 f150 standard.i6 All stock except smog pump deleted. 165k on sped
Here's a run down
Came home from work the other day and went to go to Walmart. Truck was shaking real bad. Tried to go. When I left driveway( 1/2 mile gravel road) tried to put it in 3rd(1200 Rpm) she started shaking really bad,, especially the shifter. Turned back and Popped hood and checked.
Engine visible shaking with a slight ticking that was most audible somewhere near injector 1 and 2(front).
Smelled/listened to exhaust. Smelt semi-rich but it always did
Engine on: Pulled plug wire 1 and 2. Less change When 1 was pulled.
Took off spark plug 1, looked decent no fouling. Put plug back but left wire off, wire sparked when started. Put plug on wire and started. Orange spark.
Tried to test with DMM. I forgot resistance reading.
Destroyed DMM in anger when it shocked me.
Checked compression 2 weeks ago, all good.
Pulled fuel filter, forgot to remove prime, sprayed gas in eyes, blindly stumbled around property and washed them off.
Backflowed fuel filter contents. Contents black. And grainy. Looked terrible.
Blew it out and and sprayed with carb cleaner.
Changed plugs and wires.
Pulled KOEO codes. Codes 87 and 41.
Now I'm here. Any help would be gladly appreciated. I need to get her moving so I can get away from this crazy situation and move on. I'm gonna run a can of seafoam in tank so try to clear out anything.
It was running awesome. Never been in a truck with so much down low.
Well anyway, troubles started earlier this week. I caught my wife running around on me and has been pretty hectic and fuzzy ever since.
1987 f150 standard.i6 All stock except smog pump deleted. 165k on sped
Here's a run down
Came home from work the other day and went to go to Walmart. Truck was shaking real bad. Tried to go. When I left driveway( 1/2 mile gravel road) tried to put it in 3rd(1200 Rpm) she started shaking really bad,, especially the shifter. Turned back and Popped hood and checked.
Engine visible shaking with a slight ticking that was most audible somewhere near injector 1 and 2(front).
Smelled/listened to exhaust. Smelt semi-rich but it always did
Engine on: Pulled plug wire 1 and 2. Less change When 1 was pulled.
Took off spark plug 1, looked decent no fouling. Put plug back but left wire off, wire sparked when started. Put plug on wire and started. Orange spark.
Tried to test with DMM. I forgot resistance reading.
Destroyed DMM in anger when it shocked me.
Checked compression 2 weeks ago, all good.
Pulled fuel filter, forgot to remove prime, sprayed gas in eyes, blindly stumbled around property and washed them off.
Backflowed fuel filter contents. Contents black. And grainy. Looked terrible.
Blew it out and and sprayed with carb cleaner.
Changed plugs and wires.
Pulled KOEO codes. Codes 87 and 41.
Now I'm here. Any help would be gladly appreciated. I need to get her moving so I can get away from this crazy situation and move on. I'm gonna run a can of seafoam in tank so try to clear out anything.
Last edited by Kentuckysix; Aug 11, 2017 at 08:00 AM. Reason: Forgot engine info
Senior Member
Joined: Jul 2007
Posts: 3,806
Likes: 480
From: Cape Girardeau MO
Welcome to the site! Sounds like you've had an interesting coupla weeks there.
Code 87 is a fuel pump circuit fault, with a recommendation to check the inertia switch. Code 41 is a system lean fault. Offhand, seems like the two could be related to the same problem, being a fuel starvation issue...?
The 87s came with a two fuel pump setup. One low pressure pump in the tank (each tank if a dual setup), and a high pressure pump along the driver side frame rail, about under where the brake pedal is. Might check to verify that you hear/feel both 'buzzing' during the two second charge when the ignition key is rolled to On. Not sure what exactly triggers the 87 fault - haven't run into an intermittent inertia switch, but fuel pump relays over by the brake master cylinder have been known to get flaky, as well as the unusual but not unheard of outright pump failure. As a note, some members have replaced this setup with a single high-pressure pump in the tank, as done on the newer model years of that generation - that may be what has happened if you don't see the pump along the frame rail. I think they went to the single fuel pump in the tank around 90 - I remember my 89 had the two pump arrangement.
If the fuel filter was as you described, probably a good idea to just replace. Additionally, there is a pickup screen at the pump in the tank that sometimes fouls - no easy way to get at this to check / clear. Suggest the priority thing is to check your fuel pressure at the fuel rail on the engine - should be keeping at least 35psi for the 5.0L, some members suggest the pressure should be a bit higher for your 4.9L...? For an additional degree of difficulty, there's a vacuum operated pressure regulating valve at the end of the fuel rail, these have been known to occasionally fail.
On the ignition side of things, concerned about the orange spark. Should be more towards bluish. Thinking it's not the TFI or the PIP modules, as these typically either work or don't without much in between, but wondering about the coil as you've already changed the other suspect - the wires. There are resistance specs to check before blindly dumping dollars on replacing, if you can lay your hands on another DMM. :-)
At any rate, hope this helps more than confuses. Good luck, and keep us posted.
Code 87 is a fuel pump circuit fault, with a recommendation to check the inertia switch. Code 41 is a system lean fault. Offhand, seems like the two could be related to the same problem, being a fuel starvation issue...?
The 87s came with a two fuel pump setup. One low pressure pump in the tank (each tank if a dual setup), and a high pressure pump along the driver side frame rail, about under where the brake pedal is. Might check to verify that you hear/feel both 'buzzing' during the two second charge when the ignition key is rolled to On. Not sure what exactly triggers the 87 fault - haven't run into an intermittent inertia switch, but fuel pump relays over by the brake master cylinder have been known to get flaky, as well as the unusual but not unheard of outright pump failure. As a note, some members have replaced this setup with a single high-pressure pump in the tank, as done on the newer model years of that generation - that may be what has happened if you don't see the pump along the frame rail. I think they went to the single fuel pump in the tank around 90 - I remember my 89 had the two pump arrangement.
If the fuel filter was as you described, probably a good idea to just replace. Additionally, there is a pickup screen at the pump in the tank that sometimes fouls - no easy way to get at this to check / clear. Suggest the priority thing is to check your fuel pressure at the fuel rail on the engine - should be keeping at least 35psi for the 5.0L, some members suggest the pressure should be a bit higher for your 4.9L...? For an additional degree of difficulty, there's a vacuum operated pressure regulating valve at the end of the fuel rail, these have been known to occasionally fail.
On the ignition side of things, concerned about the orange spark. Should be more towards bluish. Thinking it's not the TFI or the PIP modules, as these typically either work or don't without much in between, but wondering about the coil as you've already changed the other suspect - the wires. There are resistance specs to check before blindly dumping dollars on replacing, if you can lay your hands on another DMM. :-)
At any rate, hope this helps more than confuses. Good luck, and keep us posted.
Last edited by wde3477; Aug 11, 2017 at 12:52 PM.
Thread Starter
Junior Member
Joined: Aug 2017
Posts: 23
Likes: 3
Thanks for the reply. Most other forums haven't come with an explanation. I'm going to do the fuel filter in 2 hours once it dries alittle(just had rain).
I have the 2 tank setup. I tried switching to other tank. Same thing happens except there is a low whining or moaning that's hard to locate. It seems like it's coming from either high pressure pump or fuel filter. I'm trying to find a friend who is a diesel mechanic to borrow his pressure gauge as I'm very limited on my movement. I'll change filter and let you know.
On the fuel side of things. Does this engine have a fuel pressure regulator? Could that be a culprit? I want to eliminate fuel problems while I can and then switch over to electrical.
The old plugs/wires had bad carbon tracking from a busted coolant line/age. I assumed that was the cause of the orange spark. But I'll start working on ignition components too. I can find a DMM later tonight and I have an analog readily available.
Thanks in Advance.
I have the 2 tank setup. I tried switching to other tank. Same thing happens except there is a low whining or moaning that's hard to locate. It seems like it's coming from either high pressure pump or fuel filter. I'm trying to find a friend who is a diesel mechanic to borrow his pressure gauge as I'm very limited on my movement. I'll change filter and let you know.
On the fuel side of things. Does this engine have a fuel pressure regulator? Could that be a culprit? I want to eliminate fuel problems while I can and then switch over to electrical.
The old plugs/wires had bad carbon tracking from a busted coolant line/age. I assumed that was the cause of the orange spark. But I'll start working on ignition components too. I can find a DMM later tonight and I have an analog readily available.
Thanks in Advance.
Thread Starter
Junior Member
Joined: Aug 2017
Posts: 23
Likes: 3
I checked fuel pressure. Was around 46 idle and went up to 55 at load.
DMM also ready.
I rechecked codes and now it's giving me nothing. Just code 67 for not holding down clutch and code 11 on continuous.
DMM also ready.
I rechecked codes and now it's giving me nothing. Just code 67 for not holding down clutch and code 11 on continuous.
Senior Member
Joined: Jul 2007
Posts: 3,806
Likes: 480
From: Cape Girardeau MO
The fuel pressure regulator is at the end of the fuel rail, mine was towards the firewall at the back of the engine, about the diameter of a quarter about an inch or so tall, with a flange thing. Should have a vacuum line going to it. Haven't really heard of them failing outright, more often just start to leak. Given your fuel pressure, suggest it looks to be OK.
Don't have my Chilton book anymore with the coil, TFI, and PIP resistance specs, but thinking the coil specs were something like 0.8-0.9 ohm across the primary, and 800-900 (???) ohms across the secondary, which is measured between the coil wire post and the primary (-) post. Recommend to validate these specs as correct - only thing worse than no info is the wrong info sending you down a path that may not need to be taken. :-)
Codes clearing up is a good sign, hopefully on the road to having the problem(s) fixed.
Don't have my Chilton book anymore with the coil, TFI, and PIP resistance specs, but thinking the coil specs were something like 0.8-0.9 ohm across the primary, and 800-900 (???) ohms across the secondary, which is measured between the coil wire post and the primary (-) post. Recommend to validate these specs as correct - only thing worse than no info is the wrong info sending you down a path that may not need to be taken. :-)
Codes clearing up is a good sign, hopefully on the road to having the problem(s) fixed.
Trending Topics
Senior Member
Joined: Jul 2007
Posts: 3,806
Likes: 480
From: Cape Girardeau MO
Checking the coil resistance? Eh, just lift the primary leads (+) and (-) off the coil, then remove the coil secondary wire going to the distributor in order to electrically isolate the coil from the rest of the truck, and ohm away. I typically removed the coil for convenience, not necessary - just didn't like trying to get a measurement looking off to the side at the DMM while stretched and strained across the motor - getting too old for that. :-)