Never ending idling problems

[kxri318]

Not a very good way to set the timing. Harbor Freight has the timing light for $31.00. If everything is correct, you should have gotten some codes. Looks like your code reader is not working.

I guess I could pick that up just to fine tune it. Anyway, the code reader is basically brand new. Bought it just a couple months ago. I got a code out of it for a second a while back which was EGR Pressure Feedback, though all EGR stuff is brand new.

 

[kxri318]

Check fuel pressure and run a compression check

The fuel pressure testing kit I rented out from Autozone doesn't press the valve down far enough to release the pressure on the schrader valve so that didn't work. It did come with a fitting to test the pressure right in the line but I just haven't had time for that yet. But I did get a new timing light, set the timing to 12 degrees BTDC, took all the fuel injectors out and sprayed brake clean through them just to make sure they weren't clogged at all. It runs much smoother now, but still seems to miss/shake every so often. When taking out the plugs, I did notice that plugs on cylinders 4-6 were darker than on cylinders 1-3 (about 1 y/o plugs, 1500 miles w/ them) if that may point to anything. I also noticed that with the coil disconnected from the rest of the spark plug wires, it arc'd a bit on itself. The coil was replaced before I got the truck but was wondering if that was normal (see vid: https://www.youtube.com/shorts/SqinDjQFVws).

Compression Test Results:
Cyl 1: 135/140
Cyl 2: 140
Cyl 3: 145
Cyl 4: 135
Cyl 5: 145/150
Cyl 6: 145

 

[Josh B]

Looks like the left bank is running stronger than the right bank

 

[rusty ol ranger]

Sounds like maybe the coil has an issue.

 

[franklin2]

Since messing with the injectors helped it, why not run the fuel down low in the fuel tank and then put a can of sea foam in and run it through. If you want to try your fuel pressure again, you can take the guts out of the fuel test port like you would a tire, and then put the tester back in place.

 

[kxri318]

Since messing with the injectors helped it, why not run the fuel down low in the fuel tank and then put a can of sea foam in and run it through. If you want to try your fuel pressure again, you can take the guts out of the fuel test port like you would a tire, and then put the tester back in place.

Messing with the injectors didn't seem to do anything, but atleast now clogged injectors aren't a possibility. After I cleaned the injectors out and then started it up, it sounded just as bad as it did when I set the timing by ear. Getting the timing dialed in with a timing light was what made it run better. A can of Sea foam is probably a good idea still

 

[kxri318]

Looks like the left bank is running stronger than the right bank

But what does that mean as for problem solving?

 

[kxri318]

Sounds like maybe the coil has an issue.

Maybe there's something up with the plug wires arcing. I'm almost 100% sure they're the original wires. Is there a way to test that? Probably the best thing to do before just going ahead and replacing the coil which was replaced at some point.

 

[rusty ol ranger]

Maybe there's something up with the plug wires arcing. I'm almost 100% sure they're the original wires. Is there a way to test that? Probably the best thing to do before just going ahead and replacing the coil which was replaced at some point.

If they are original wires yes start there

 

[Josh B]

But what does that mean as for problem solving?

It just seemed to me it might have a kinda "limp" to it. Other than that speculation I really have no clue.
If I had 2 coil packs, which I do, I might try swapping one to see if it changes anything.
I am not sure tho if the sides operate individually or not, as I mentioned it was merely a speculation

 

[bobbywalter]

My truck has been idling really rough since I got it, I've replaced just about every single sensor there is on this truck except for the TPS. After replacing all that, I decided to test for vacuum leaks and I saw a leak from the lower intake manifold gasket and the pcv valve. Replaced both gaskets and the breather gasket on the right too, now it runs even worse. Both then and now, it runs so rough the engine shakes bad at random times. I'm not even 100% sure how to set the timing because there's a hole but also an almost arrow looking metal piece pointing on the markings on the harmonic balancer so I'm not sure if the timing is right. It idle surged rarely before, but now its an extremely bad idle surge to the point where I have to hold the brakes to stop myself from slamming into the back of the garage. It's also varying the RPMs all over the place as it feels like. It would idle high but then go down to the point where its struggling to stay running without me touching the gas pedal at all. I've been fighting this truck for the past year and I'm so sick of it. I can't figure out what's causing these things.

What was the result of the vacuum test?

If the map is reporting correctly...and tps. And you have proper fuel pressure...with no codes. Your injectors should be flow checked or replaced....otherwise it's a faulty ecm.

 

[kxri318]

What was the result of the vacuum test?

If the map is reporting correctly...and tps. And you have proper fuel pressure...with no codes. Your injectors should be flow checked or replaced....otherwise it's a faulty ecm.

The vacuum test was just some smoke and seeing where it leaked out, no actual gauge hooked up. The map is brand new, TPS is not new, but I feel like if its the TPS, it would be loping at all times. It only happens after warming up now and idle only. Still have to check fuel pressure, though the injectors seemed to be spraying fine when I sprayed brake clean through them. Not sure how I would flow check them for sure though. Is it better to scan for codes doing the engine running test or while doing the engine off test?

 

[kxri318]

Maybe this has to do with this, not sure but it's worth mentioning. My fuel vent system isn't working right. Vent is perfectly clear and filler neck is not kinked but it still kicks off every couple seconds when filling up on a low speed. I blew through the vent line to confirm there's no blockages too. I'm not sure what the issue is. My fuel gauge also doesn't go to completely full even when the tank is full enough to spit gas out the cap (I can't tell when its full by the pump turning off since it turns off on its own so much)

 

[franklin2]

The fuel tank does not vent through the small line leaving the top of the tank and going up front when filling at the station. You are pouring a lot of liquid into the tank, the same amount of air needs to come out. Problem is, this air needs to be diverted away from the fuel coming in or it will start splashing and gulping, causing the station filler gun to shut off.

I am not sure how they vented your particular tank. On the f150's, the earlier models they filled the fuel through the large filler hose, and they had a small corrugated plastic hose mounted at the top of the large hose inside to direct the air out and away from the fuel going in. This didn't work that great, and the smaller hose was famous for falling down inside the large hose causing filling problems on these trucks (1980-86).

Sometime around 1987 they changed things around and it worked much better. They mounted a smaller rubber hose to the fill spout, and this smaller rubber hose layed on the inside the larger rubber fill neck hose. The fuel from the station nozzle went down the smaller rubber hose, and the air came back up the large fill neck hose and vented through a slot in the fill neck. This system worked much better than the older style.

Not sure how they set up the rangers, but it's going to be along one of those themes above.

 

[Cees Klumper]

Long shot but check your spark plug wires are connected in the right sequence / firing order. Maybe try swapping out a new ignition module. And is the distributor working properly, i.e. is the spark timing nice and steady? And did you set timing with SPOUT connector removed?