Ghrrum

So I've got a bit of a mystery. It seems my truck decides to not fire for a moment or two, then will work fine for a short period, then do it again, and on and on. There is no hesitation or loss of power, it idles and starts fine, but when I put it in gear and start to let out the clutch, it will have 1-2 seconds where it seems the spark plugs aren't firing.
Since this decided to start happening when I was planning on doing some maintenance/upgrades on it. Here are the things I've replaced due to them being dead or my suspicions of them going dead soon. Unless otherwise noted I was the one doing the replacement.

Timing chain, guards, and valve adjustment (shop)
Fuel pump and strainer(shop)
Plugs
Rotor
Cap
Ignition coil
Cables


There is one other odd note regarding it doing this, and it points me towards it being a high voltage electrical issue, the radio gives me a nice burst of interference that sounds in tune with the engine RPM.
Right now my current suspect is the ignition control module. I'm looking for outside input as I'm not entirely sure I'm on the right track.

wyoming9

iTrader: (1)

Ok if your ignition is losing power your engine is in effect turned off. .
So if your still in gear it restarts from compression if your stopped you need to crank it to restart??

This is what is happening??

I would check and clean perhaps upgrade all my main grounds first thing paying close attention to the one for the ECU

Also possible you could have a poor connection in any of the ignition system since you changed the coil and wires.

Igniters when they fail most often don`t work at all but anything is possible

skypilot

iTrader: (1)

Also there is a chassis ground on the back of the cylinder head, make sure its good too! Also check that long wire to the ignitor for corrosion or metal fatigue.

MAINETOY

iTrader: (2)

TPS out of range or bad causing a dead spot?

Ghrrum

wyoming9,
I'm assuming that compression is what gets it going again, it has yet to have this occur when at idle or while stopped. You are in effect correct that my engine is turned off when this happens. As there is no other electrical symptom that I can see when it occurs, I doubt that it is a more significant electrical short farther up system. Double checking/cleaning/upgrading the ground connections seems like a good idea and something I should do anyway. I'm doubting that there is any NEW issue with the connections between components in the ignition system since the problem has at least remained the same.

MAINETOY,
TPS seems doubtful as the issue doesn't occur in tandem with any specific position on the gas pedal, racing the engine while not in gear does not cause the problem to occur either. I'd expect the symptom to be reproducible if it was a worn spot on the TPS.

skypilot
I will double check them, thanks for the heads up.

Odin

I believe I had a ground issue cause that when I was running full MSD ignition on my old 66 Nova. Even if it's not the problem cleaning all the ground wires sounds like a great idea to me. Given the age of these trucks if nobody has done any good maintenance on them they're probably due for a good cleanup or replacement.


Here's a link for ground wire locations on a 22re and some other testing stuff. https://www.yotatech.com/forums/f166.../#post52260297
I'm not done with it



Is this an FI engine or carbed, your title says 22R.
I didn't think carbs had TPS sensors but what do I know.

If it's an FI engine I'd for sure check the Trouble Codes. The CEL on the dash won't always light up when one is present. In fact mine had two active codes present but the light never came on. If any codes show up make sure you write them down before you disconnect the battery because that will clear them.
How to check them http://www.4crawler.com/4x4/CheapTri...odes/#Late22RE


.

Ghrrum

Odin,
Thanks for reminding me, this is not a carb engine, it is fuel injection. Sorry for the confusion on that bit.
I'll be fiddling with it a bit more today to see what else I can find.

Mr.Utah

Bad or cheap plug wires can cause radio interference, install OEM or better. Plus, the cheap wires pull apart easily.

Mr.Utah

I was also going to say that a bad distributor can cause engine stalling.

Ghrrum

Update time:
I checked all the ground connections I could find (Found all 4 in the article that Odin linked) and checked em out. They looked good and tested fine (continuity and voltage drop). I further checked ground connections on the ICM, from both the battery and a nearby point on the truck body, also tested fine.

Mr. Utah,
On a whim I decided to double check the plug cables, they are in good shape and tested fine for resistance. The interference that is occurring only happens when the engine quits getting spark, the rest of the time (like at idle) it is quiet and I can't hear any interference.
Further, I checked the distributor when I was replacing the cap. There were no signs of damage, significant corrosion, or wear. I appreciate the suggestion to put eyes on it again regardless.

Tomorrow I think I'll see about trying to pull codes from the ECU

Odin

The hardest thing about checking the codes is finding the correct diameter paper clip and not sticking it in the wrong hole.
I just carry the paper clip in my glove box.

I'm just wondering if you've got a code 42 fault along with something else going on. Maybe,... maybe not.
Code 42 is a Speed Sensor fault and when it trips it can cause the engine to lose power and almost die, then quickly recover.

Ghrrum

Update:
Just finished checking to see if it was throwing any codes. It's not, as far as I can tell. The check engine light just flashes at a nice steady rate. I counted it up to 60 twice just to make sure, so I've no idea if that is normal or not.

Odin

That would be normal, or no fault codes are being stored.
Dang IDK

You have put some miles on it since you last disconnected the battery haven't you? That should put a code back on it -IF- there was one to begin with.

bswarm

Are you talking about a shake while you let the clutch out? That would be called a chattering clutch and is not a misfire.

Ghrrum

bswarm,
It's not clutch chatter, it's the engine not firing. I've experienced the difference.

Odin,
It's got maybe 10 miles or so on it since I swapped out the parts. Symptom has occurred several times in that distance, so if there was a code, it should have shown.

Since those are ruled out I'm going to throw parts at it and hope for the best. First up will be locating an ICM to test/replace the existing one, a pickup coil, and god knows what else. If those two don't do it, I'll be handing it off to one of the professional wrenches I know and let them fight with it.

bswarm

It only does it as you let the clutch out? That's pretty specific. If it doesn't do it any other time, see if there's a wire shorting out on the clutch linkage. That is, if it isn't clutch chatter.

Ghrrum

bswarm,
It WILL do it when the clutch is fully engaged and my foot isn't on it. I'm pretty certain it's not related to clutch or drivetrain components. After all, that wouldn't explain the radio interference or apparent sudden loss of spark to the engine.

I do appreciate the alternate idea and suggestion though.

Odin

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bswarm

OK, that makes more sense then. Do a voltage drop test from Battery Neg to block, and chassis to block, maybe even do it while bumping the clutch to simulate motor vibration. Spark needs a good ground route, if it can't find one it'll do the radio interference thing.
Some basic voltage drop tips... http://www.fluke.com/fluke/uses/comu...seVoltDrop.htm

Odin

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