Which fuses to pull for compression test?

I know nothing about mechanics but am learning, so forgive a stupid question.

Which fuses do I pull to disable fuel/spark in my 2002 Tacoma, 2.4? I think I have the fuel part figured out--it's the one in the cab for the fuel pump. What about spark? Thanks.

 

My bad. It's the EFI, I think, which for the life of me can't figure out how to pull. It doesn't just come unplugged, and no instructional video I can find anywhere.

Help, please.

 

If you have the fuel pump fuse unplugged that is good enough and don’t need to pull any other fuses.

 

Here is a video for the v6. I know you have the 2.4, but it may help you out.

https://youtu.be/ky7bndfFpO0

 

Thanks, but still no help. Video says I have to do spark, but can ignore fuel pump. Took out the IGN fuse from cab and the EFI 20A from the engine compartment fuse box. Won't crank.

 

https://www.tacomaworld.com/threads/compression-specs-for-all-1st-and-2nd-gen-tacomas.320905/

 

Try putting the IGN fuse back in. Then pulling the EFI relay.
Unplugging the coils should kill spark.

 

Doesn’t look like you have to do anything

 

Which ones? Thanks again.

 

Efi. Bottom center haha

 

You can either do it like the manual says, and press the gas ALL THE WAY DOWN, and then crank the truck.

Or pull the EFI Relay. Then let the truck run until it does. (If it even runs at all)
Then preform compression test.

 

Did you watch the video or read the links and FSM which have been posted? You don't have to remove any fuses. Just remove the spark plugs and coils, like the shared resources have all directed.

 

Mystery solved, and boy, is this embarrassing.

When performing a compression test, do not have your 88-year-old father turn the motor over. The elderly tend to forget how stick shifts work, no matter how much they insist otherwise.

All better now. And thanks for your help and patience.

 

And hooray. Compression is fine. Now I need to figure out what's up with 3 cylinder. Getting a 303 code, and it's misfiring. Three different places have come up with three different explanations. It's not plugs or coils. Replaced all four. Any opinions on whether to go with max air flow sensor or O2 sensor first?

 

Leak down test. Do you lose coolant?

 

I’d check valve clearances, or do the leak down test as suggested

 

You said it's not plugs or coils but you didn't mention wires.

 

ignore

 

Ignore

 

This started a couple months back when the check engine light came on. Auto parts store diagnosed O2 sensor, which could wait. Sporadic misfiring began about a month ago. Rushed to the shop a couple days ago when the light started blinking as misfiring increased. Shop said I needed a coil and plug on cylinder three. I replaced all four. Didn't help. A fellow on the internet said that if it's misfiring on cylinder three, don't assume coil and plug, do a compression test to rule out a burnt valve because that's a common issue on the 2.4 as miles pile up (I'm at 175K). So I did that before investing in a mass air flow sensor, as an auto parts store (not same as first) recommended after finding P0300, P0303 and P0136 (see below).

Pressure on three of four cylinders (I didn't do cylinder four, it's a long story) is 125 psi, which is low, but at least consistent. I did the test with the engine cold. Once i had it all back together, the check engine light went off and it was back to normal, even though I'd done nothing but a compression test. Didn't last five miles. The light is back on with misfiring aplenty. That was last night. This morning, light is off again, but I have no confidence. Did it get "fixed" because the engine was cold? Why is it different after a compression test than before? Sheer coincidence?

It leaks no coolant and uses virtually no oil--no smokes or drips of any kind. The K and N filter was dirty until a few days ago but now is clean. Thinking I'll go with max air flow sensor on theory that the dirty air filter might have done something, but that's a WAG/flat hope. Checking valve clearances is beyond my skill level, and I can't find a competent mechanic anywhere around here.