What would cause a miss under load? 98 LS1 TA
08-29-2011, 06:32 AM
#21
only had time to pull 2 plugs tonight, both are destroyed, white and the electrode is gone...some sort of bosch platinum plug (too hot or improper gap???). Other thing I'm wondering about is this, I picked up some NGK platinum plugs and they gave me part #3186 which is "5" heat range plugs. I always thought TR55 was the stock heat range on LS1's as far as the copper anyways? Also as far as I know stock gap is .060 and according to the person at the parts store NGK calls for a .040 gap. I dont see why it would be that different so the 2 I put in already I gapped at .050, anyone else experienced this?
NGK #3186 is a platinum tiip. It is the right heat range (same as TR5s). The correct gap (according to GM and NGK) is 0.040 inch. A larger gap provides a stronger spark, but is also more likely to misfire later in its life.
08-29-2011, 09:14 AM
#22
only had time to pull 2 plugs tonight, both are destroyed, white and the electrode is gone...some sort of bosch platinum plug (too hot or improper gap???). Other thing I'm wondering about is this, I picked up some NGK platinum plugs and they gave me part #3186 which is "5" heat range plugs. I always thought TR55 was the stock heat range on LS1's as far as the copper anyways? Also as far as I know stock gap is .060 and according to the person at the parts store NGK calls for a .040 gap. I dont see why it would be that different so the 2 I put in already I gapped at .050, anyone else experienced this?
You'll should okay at .050, the new preferred gap is .040, but the original was .060 IIRC, if it wasn't .060 on our cars then it was on many other GM's. Mine are gapped at .040. I would just pull the 2 back out and gap them to .040.
Last edited by 00pooterSS; 08-29-2011 at 09:54 AM.
08-29-2011, 09:41 AM
#23
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only had time to pull 2 plugs tonight, both are destroyed, white and the electrode is gone...some sort of bosch platinum plug (too hot or improper gap???). Other thing I'm wondering about is this, I picked up some NGK platinum plugs and they gave me part #3186 which is "5" heat range plugs. I always thought TR55 was the stock heat range on LS1's as far as the copper anyways? Also as far as I know stock gap is .060 and according to the person at the parts store NGK calls for a .040 gap. I dont see why it would be that different so the 2 I put in already I gapped at .050, anyone else experienced this?
08-29-2011, 02:08 PM
#24
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Did some research and called ngk. GM changd suppliers in 03 and sent out a new bulliton the gap should be .040 from then on. Ngk 5 come gapped at .040 while 55 come pre gapped at .060 (no hange in heat range) the sticker under the hood states .060 as well for before the general changed suppliers. I'm putting the 5's in at .050 as ngk said either wil be fine. Call it a happy medium between the 2.
08-29-2011, 02:10 PM
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The electrodes of Bosch platinum plugs are surrounded by an extended insulator so the electode may appear "gone." even when new.
NGK #3186 is a platinum tiip. It is the right heat range (same as TR5s). The correct gap (according to GM and NGK) is 0.040 inch. A larger gap provides a stronger spark, but is also more likely to misfire later in its life.
NGK #3186 is a platinum tiip. It is the right heat range (same as TR5s). The correct gap (according to GM and NGK) is 0.040 inch. A larger gap provides a stronger spark, but is also more likely to misfire later in its life.
08-29-2011, 11:49 PM
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Problem Solved. plug wire for cylinder 6 was split in 2. 1 thread holding it together. Runs a lot better now. Still can hear an occasional stumble or half miss at idle once and a while but nothing consistant that warrents any concern I dont think. Now to figure out why I changed the oil and lost some oil pressure....never ends. Thanks to everyone for there imput.
02-05-2016, 07:35 PM
#28
I know im brining it from the dead but had a question about all this miss fire crap. Would a miss fire cause hp tuners to stop when logging. Been having this happen ever since I switch out injectors (127's). When I get under load in 1st, 2nd or third the car will miss/ lose power momentarily causing hp tuners to stop logging. Ive switched out plug wires and plugs but the damn car still does it. Cant even finish tuning it cause of this annoying reoccurrence. Any help.greatly appreciated.
AES 390
F1a
Bosch injectors 127
Alky control
AES 390
F1a
Bosch injectors 127
Alky control
02-05-2016, 08:29 PM
#29
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I haven't figured mine out yet, but in 1st gear only, at about 5600-5700 rpm, It feels like I get a miss or hit the rev limiter... I'm shifting not much longer ad I have gears(likely 4:30s) so I don't know if the tach just can't keep up, or if I actually have a miss.
02-05-2016, 10:33 PM
#30
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What would cause a miss under load? 98 LS1 TA
Originally Posted by Tirefire
...
Would a miss fire cause hp tuners to stop when logging.
Would a miss fire cause hp tuners to stop when logging.
Been having this happen ever since I switch out injectors (127's). When I get under load in 1st, 2nd or third the car will miss/ lose power momentarily causing hp tuners to stop logging. Ive switched out plug wires and plugs but the damn car still does it. Cant even finish tuning it cause of this annoying reoccurrence.
if this is an F-car, check if the battery is loose, if it is then it moves and shorts out on the AC accumulator.
02-05-2016, 11:22 PM
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02-06-2016, 04:58 PM
#33
I doubt that's the problem. I do remember the wires near the starter getting to close to the headers. I believe that one of the wires goes to the crank sensor. Its possible that I damaged those wires cuz my o2 sensors are also not working, and I believe o2 sensor wires are part of the wires that are routed through that area. Anyone know if I can buy those wires on the passenger side or do I need to buy all the harness? Thx
10-01-2016, 07:05 AM
#34
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Ok I am brand new on this site. I have 3 ls1 cars just bought procharged ls1 needed motor done took it out did motor same way was built wen I bout it now car back running but I have misfire all over the place.. mostly under load. No lights in dash. Only see it in scanner tool.. checked grounds new plugs wires. Fuel ... I'm way lost please can anyone help?? Thanks
10-02-2016, 08:19 AM
#35
Had the same issue on my old SS.. had new plugs NGK TR55 and msd wires.. no SES.. drove fine until I hit wOT.. found cracked porcelain on 1 plug that I must have cracked on install.. took looking at it with a GM tech 2 to determine the cylinder effected and once we pulled the plug and looked real close we found the crack.. replaced and ran like and champ
10-09-2016, 11:31 AM
#36
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I had the same issue a few years back. Problem was the metal clip inside the wire to the plug had broke. I was so upset because I had bought Taylor wires and they only had 200 miles on them... I have great success with MSD wires over the years and will continue using them.
10-09-2016, 09:11 PM
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