dp213 Posted August 26, 2014 Share Posted August 26, 2014 My 98 gt seems like its running on 3 cylinders. No codes present, I checked the timing and its good. It had an o2 censor code so I replaced it but no change in his it runs. I'm wondering if a bad head gasket would not throw a code. Thanks Dp213 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 26, 2014 Share Posted August 26, 2014 how old are the plugs and plug wires? Is there any oil on the plug boots? Quote Link to comment Share on other sites More sharing options...
dp213 Posted August 26, 2014 Author Share Posted August 26, 2014 No oil on them but not sure how old they are Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 26, 2014 Share Posted August 26, 2014 (edited) move the wires around if they'll reach and see if the misfire follows the wire. Some folks have found arcing by water-misting the coil and wires of their idling engine at night. If the easy tests don't find anything, might need a compression/leakdown test or drop the exhaust manis and see if a valve guide has shifted? Edited August 26, 2014 by 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
lmdew Posted August 26, 2014 Share Posted August 26, 2014 (edited) MAF if it idles fine but has on power when you step on the gas Edited August 26, 2014 by lmdew Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted August 26, 2014 Share Posted August 26, 2014 Is it shaking/ shuddering like its misfiring? Quote Link to comment Share on other sites More sharing options...
dp213 Posted August 26, 2014 Author Share Posted August 26, 2014 Or not firing on all cylinders. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 26, 2014 Share Posted August 26, 2014 if you think it's a single dead cylinder, carefully pull the plug wires one-at-a-time. The wire that doesn't kill the motor/makes the least difference in idle = the bad cylinder. Quote Link to comment Share on other sites More sharing options...
dp213 Posted August 27, 2014 Author Share Posted August 27, 2014 Looks like #1 & #3 aren't firing. I changed the plugs, wires, and distributor. No change. Quote Link to comment Share on other sites More sharing options...
nipper Posted August 27, 2014 Share Posted August 27, 2014 The cylinders fire 1-2 and 3-4. If both are not firing on the same side, look at the timing belt, has it jumped? Quote Link to comment Share on other sites More sharing options...
dp213 Posted August 27, 2014 Author Share Posted August 27, 2014 Timing is good. I thought the firing order was 1,3,2,4. Quote Link to comment Share on other sites More sharing options...
nipper Posted August 27, 2014 Share Posted August 27, 2014 If it has no distrubutor (which it shouldnt) it has coil packs, which are waste spark systems. In a waste spark system the coils will fire in pairs, hence 1-2, 3-4. It gets a little confusing, ignition order (firing) is as you said. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted August 27, 2014 Share Posted August 27, 2014 Firing order is 1-3-2-4 Plugs are fired in pairs 1&2, 3&4. The coil fires both plugs at the same time. It's a waste spark system. One plug fires on tdc compression, the other on tdc exhaust stroke. Cylinders 1&3 are the right half of the block so if those are misfiring the problem could be jumped timing. Quote Link to comment Share on other sites More sharing options...
nipper Posted August 27, 2014 Share Posted August 27, 2014 Have you thrown a vac gauge, or done a compression test yet? What are you calling a distributor ? Quote Link to comment Share on other sites More sharing options...
dp213 Posted August 27, 2014 Author Share Posted August 27, 2014 My bad. Coil pack. Had the blazer on my brain for a second 1 Quote Link to comment Share on other sites More sharing options...
dp213 Posted August 27, 2014 Author Share Posted August 27, 2014 Doing a compression check after work tomorrow and going to see if I can find a vacuum gauge also Quote Link to comment Share on other sites More sharing options...
lmdew Posted August 27, 2014 Share Posted August 27, 2014 put a dollar bill very close to the exhaust. if it gets pulled back into the pipe while running you have a bennt valve or hg leak Quote Link to comment Share on other sites More sharing options...
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