compression test…um

[Lee Ann]

Hey college man,

I got all set up for my compression test and when to crank the engine and nothing. Is it possible that I don’t just pull the plug on my DIS?

Thanks

P.S. Re-reading Haynes now. Maybe battery is at the end of its life?

Topic

[college man]

[quote=”lar1969″ post=93693]Hey college man,

I got all set up for my compression test and when to crank the engine and nothing. Is it possible that I dont just pull the plug on my DIS?

Thanks[/quote]

The car did not crank?

[Lee Ann]

no, nothin.

[Lee Ann]

Maybe the battery is shot? I haven’t had starting problems.

[college man]

Did you pull the right fuse? fuel pump

[Lee Ann]

I pulled the fuel pump relay on the passenger side (cabin)kick plate.

[college man]

[quote=”lar1969″ post=93700]I pulled the fuel pump relay on the passenger side (cabin)kick plate.[/quote]

do you have jumper cables to jump the car?
sure it was the fuel pump relay and not the
starter relay?

[Lee Ann]

I do.

[college man]

[quote=”lar1969″ post=93702]I do.[/quote]

Pull the plug to the ignition module to disable spark.
remove all the plugs.

[Lee Ann]

I should have said that I have jumper cables available here at home. I also have a trickle charger available.

But yes, I did disable the ignition by pulling the connector (the same connector that I pulled to do the maintenance on the coils and module this past weekend).

Yes, I pulled all the plugs (and of course the plug boots but left the spark plug wire connectors at the towers, with the ignition connector removed).

[Lee Ann]

I have double checked the relay that I pulled. It is indeed the fuel pump relay.

[college man]

Keep us posted how it goes.

[Lee Ann]

I guess I’ll just button it up for today (and hope it starts) and try again tomorrow. It’s good to know when to quit…temporarily.

Thanks for your time, college man!

[Lee Ann]

Ok, so I was able to get it together.

The following are dry test data collected on a COLD (luke-warm) engine:

compression, cylinder 1: 180 199 psi, 2: 179 psi, 3: 200 197 psi, 4: 204 202 psi.
Compression spec (Haynes Manual): Standard 190 psi minimum, Service limit 180 psi minimum.

I realize these numbers are not accurate and will repeat at normal operating temperature tomorrow. It was a good exercise and it gives me an idea of what to expect tomorrow (between 11% to 13%). I should be able to get it done faster next time.

Thanks, again, college man.

[EricTheCarGuy]

Looks like you’re right on the border with one of those cylinders. Once you find a problem cylinder, the next step would be a leak down test.

You don’t need to buy a new tester. You can use the compression tester hose with the schrader valve removed as shown in the video.

Good luck and keep us posted.

[Lee Ann]

Thanks for your reply.

I am just now getting my second set of data together to post.

The values did increase as a result of having the engine at operating temp (and again during wet test).

I did the whole job (including prep, testing and reassembly) in 1 hour (don’t know if that is reasonably fast).
During wet testing I made sure that there was oil in the cylinder-three squirts, and I took pics of each result and made notes.
PS-Unfortunately, I don’t have shop air.

[Author]

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