Troubleshooting the 289!

289 - 351 cid Small Block Performance
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Tristan
Posts: 724
Joined: Sat Jan 31, 2009 10:58 pm
Location: Moncks Corner, SC

Troubleshooting the 289!

Post by Tristan »

Hey everyone, after a long hiatus, I bought a new battery and fired the ol' girl back up. It gave me no issues and idled and ran like she has since the build but I never felt it was quite right.

I picked up an infrared thermometer based on something that Kevin (mahorsc) told me a while back. I lasered the temps of the headers about 1" off of the flange. A majority where real close to each other but one stood out. I was getting dark and the skeeters were eating me alive so I didn't get to record the data, but will try tomorrow. Cylinder 7 was about ~125F cooler than the others. and that's the same side that has always had a different exhaust note (may or may not be related, exhuast bends etc.)
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ants875
Posts: 929
Joined: Wed Oct 03, 2012 12:08 am
Location: Chehalis, WA

Re: Troubleshooting the 289!

Post by ants875 »

Tristan,

Good to hear from you! At this point I'd wonder what the compression of that cylinder is. Seems I remember that you did all the tune up stuff but you might check and make sure the plugs and wires are good. Let us know what that all turns out to be then maybe we will have some other ideas.

Ant
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loman
Posts: 1287
Joined: Sat Dec 28, 2013 9:03 am
Location: Missouri

Re: Troubleshooting the 289!

Post by loman »

Tristan, I agree with Ant on the compression check. When you pull the plug out of number 7, look it over real good and pull another plug and compare the two. I would think if that cylinder is that much colder in temp than the others, that plug should be showing some tell tale signs such as a really wet looking plug or a really black plug.
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CALIFORNIA CALIENTE
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Joined: Mon Feb 20, 2006 12:57 am
Location: Camarillo,California

Re: Troubleshooting the 289!

Post by CALIFORNIA CALIENTE »

Tristan,check the plug wire for that cylinder.If it is bad that cylinder will not fire! Roy.
Real Racecars have 3 pedals
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Red Eagle
Posts: 14
Joined: Thu May 05, 2016 11:27 am

Re: Troubleshooting the 289!

Post by Red Eagle »

Hi, new here and just saying. After you check compression at that cylinder and plug and plug wire and if all of those three are good. Check distributor cap and rotor button on inside for corrosion/cracks. On a previous car and motor I had, the #4 and #8 cylinders were not firing. I had a vacuum leak. Found the leak and plugged an open port on the intake that I found. I was lucky and all was good. But you are saying #7 cylinder. Hopefully it will be an easy fix. Good luck and let us know what you find.

Red Eagle
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Don't mess with an old Marine. He'll just shot you.

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