Which fuses to pull for compression test?

What does being manual have to do with a failed compression test?

 

I don’t think he stepped the clutch in.


It could be bad wire, bad injector, bad valve, or slightly leaking gasket. Leak down test is a way to check valves and it only a little different then compression test.

 

Timmy the Toolman did a good video on valve clearance checks. Look it up, it could actually help you out. I did it on mine and it improved my cylinder compression because they had worn far out of spec. I was getting intermittent misfires from low compression. If you aren't comfortable doing it yourself, I recommend taking it to the dealership to have it done. If it hasn't ever been checked and adjusted, this could be contributing to your problem. I ended up having to take my cams out to actually change the shims. You can read about that experience here: https://www.tacomaworld.com/threads...hooting-and-diagnostics-advice-needed.768000/

Also, you could check the spark plugs for oil buildup, which could prevent ignition and contribute to misfire.

 

So you're going with sheer coincidence re: the issue temporarily resolving itself? Sounds good to me. The light first went on as soon as I started it up after getting gas. I don't know whether that's a clue of any significance.

 

Being the issue is only on cylinder 3. No
I think everyone else might be right in jumping into the valves but I could see how it could be the injector too. I did miss the fact you didn’t change the wires do that 1st. Checking the valves isn’t as hard as you might think. Just shove a feeler gauge between the shim/bucket between the cam lobe. Hardest part is spinning the crank pulley around to the right spot for different cylinders. I said leak down because you will also see if it is a gasket but you stated you not losing coolant so you’ll get more information from checking valves.

 

Could also be an injector that's going bad.

 

The truck would jump the first time it was cranked if that was the case.

I assume both are smart enough to not do that again.

So I still don't understand why all the fuss over pulling fuses, relays and such, then blaming it on pops and a manual transmission.

What am I missing?

 

Idk about his truck mine has a safety feature where it won’t start without pushing the clutch in(I’m personally wanting to delete that system as I can see where it can become a problem). And if it’s in between gears or in N no won’t jump. He didnt want lose his liquid gold.

 

Makes sense. Thanks for the reminder. I had disabled that feature on my last vehicle that had that.

 

I should change all four fuel injector wires or just one?

https://www.youtube.com/watch?v=t9niwrmeFQE

 

Exactly right. I was doing everything right but that didn't matter because my assistant figured he could put the truck in neutral and it would crank, even after being told that you have to depress the clutch--the older some folks get, the more they think they know everything and don't listen. Issue was discovered when truck began rolling when I leaned against it. He hadn't put it back in gear.

I hope this clears things up for everyone.

 

Spark

I was referring to the injector it self but would make sense for You to check that too. I’d just throw a voltage meter on it see if the if the wires are good. Arizonabrain noticed when you were explaining the work you’ve done you didn’t mention spark plug wire. I’d check that. Could possibly move them around see if it changes where the misfire is happening.

 

I has coils, so like this? https://shop.advanceautoparts.com/p/denso-first-time-fit-ignition-wire-set-f1020332900nd/11732640-P

If so, I could check the existing wires with a multi meter, no?

Thanks.

 

I don’t remember how your engine is all laid out. Does your truck have those? But yes if it does the move a number 3 wire and another around see if the misfire moves. Ther is ways to find the issue rather buying and throwing a bunch parts at it unless you have the money to do so.

 

I see no spark plug wires:

 

You've got coil on plug, so you'd want to swap the coils between cylinders instead.

 

Also, it's officially become intermittent. Had a couldn't miss appointment. There now. Everything fine. So, engine light on for two months, misfiring develops, now off and on. Beginning to think maybe a loose wire leading to number three coil. Would that make sense?

 

Could be other things too. I've seen coils crack with heat and age, that can make them a little weird.

 

Replaced coils. Didn't help. Then to do compression check, took them off again and destroyed rubber plug boots, so put old ones back.

I think I can rule out coils.

 

*Cough cough* valve clearance check *cough*