Another compression question

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May 1, 2016 | 10:59 PM

SeaCarr

Thread Starter

Tuned

Joined: Oct 2012

Posts: 371

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From: Slocum, TX

Another compression question

This will be odd but I want to run a compression test. I did not think of this until I had the truck torn down to the frame. Engine is still in with the starter.
What could I use to connect a battery to the starter to crank the engine?

May 1, 2016 | 11:14 PM

twigsV10

Cargo Master

Joined: Jun 2010

Posts: 2,113

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From: Iowa

A good set of heavy duty jumper cables on good connections will work, don't use cheap lightweight cables or anything less than shiny connections.

May 2, 2016 | 10:54 AM

hiball3985

Logistics Pro

Joined: Mar 2005

Posts: 3,771

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From: tujunga, calif

You can get a remote starter switch at any auto parts store, not expensive..

May 2, 2016 | 11:28 AM

SeaCarr

Thread Starter

Tuned

Joined: Oct 2012

Posts: 371

Likes: 6

From: Slocum, TX

How would the connections be made with jumper cables? There is no solenoid between the battery and starter. Bat positive to starter, bat neg to ground?

May 2, 2016 | 02:56 PM

Martin Torres

Tuned

Joined: Feb 2016

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Negative batt to ground. Positive batt to post on starter that normally runs to solenoid.

May 5, 2016 | 05:30 PM

Textile302

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Joined: Sep 2014

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Correct me if I am wrong, but get get good readings don't you want the engine to be warm?

May 5, 2016 | 09:15 PM

hiball3985

Logistics Pro

Joined: Mar 2005

Posts: 3,771

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From: tujunga, calif

Quote:

Originally Posted by Textile302

Correct me if I am wrong, but get get good readings don't you want the engine to be warm?

Yes, that would be the best way if you had a running engine, also WOT...

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May 7, 2016 | 12:45 AM

Tedster9

Post Fiend

Joined: Apr 2002

Posts: 19,311

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From: Waterloo, Iowa

Good numbers from a cold engine while not accurate would be OK since they would only get better, as the engine warms. Maybe there's some other factors, but believe this to be the case.

Bad or failing numbers measured cold on the other hand wouldn't necessarily mean as much and would have to retest later before condemning the motor. Although a dead cylinder would be useful to know no matter what?