Guest DISCUS Posted August 3, 2004 Share Posted August 3, 2004 Recently had my engine heads ported and polished then re-installed. have some trouble with engine hesitating when rpm rise quickly, nothing noticeable when accelerating evenly. Rougher at higher RPM, I thought it was due to fuel starvation, still running stock lines but have an excellent high pressure fuel pump. ( no reservoir though) To-day pulled spark plugs and found one that does not appear to have been firing at all! Just a shiny tarnished brown look on the platinum tip. How much could the effect of one cylinder not firing create of the above problems noted? Also has anyone had experience with the platinum 4 spark plugs by bosch? Appreciate any input! Quote Link to comment Share on other sites More sharing options...
mas28O Posted August 3, 2004 Share Posted August 3, 2004 1st get rid of the platinum bosch? 4 spark plugs Put in some TR6 NGK plugs Also check your Optispark, what year do you have? Have you done any tunning on the ecm yet? Good luck Mike Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 3, 2004 Share Posted August 3, 2004 Yeah...get rid of the platinums. Regular cheap old Champions or NGKs will be better. The LT1 guys over at Z28.com have had fits with the 'pricey' plugs. That hesitation could be any of a number of things. Like Mike suggested, change the opti. 7 times out 10 it is the problem. Might as well replace the water pump while you're in there.... Best place to get suff is from Jason Cromer at Sam Taylor Buick in Florida. BEST PRICES ANYWHERE for LT1 stuff!! http://www.samtaylor.com/html/parts.html Also check your plug wires. Make sure that the routing isn't making them jump spark. If you need new ones, let me know and I will post the MSD part number for teh cut to fit set that has the opti side pre-assembled. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted August 3, 2004 Share Posted August 3, 2004 One dead cylinder will definetly cause a stumble under a fast load and high RPMS. Figure out why that plug isnt firing and fix it. More than likely the opticrap if the wires are new and the plugs are new. I also say get rid of those crappy bosch plugs, the LT1 does not like them. I tried to run the platium 2's in mine but it runs much better with the NGK TR55's. Guy Quote Link to comment Share on other sites More sharing options...
Guest DISCUS Posted August 3, 2004 Share Posted August 3, 2004 One dead cylinder will definetly cause a stumble under a fast load and high RPMS. Figure out why that plug isnt firing and fix it. More than likely the opticrap if the wires are new and the plugs are new. I also say get rid of those crappy bosch plugs' date=' the LT1 does not like them. I tried to run the platium 2's in mine but it runs much better with the NGK TR55's. Guy[/quote'] Thanks, I have isolated the problem I think, swapped plugs out and the evidence shows very differrent deposits on some and nothing on two. They were autolite platinum and will replace today. If that does not solve the problem will check the opti spark, wires have checked out! Quote Link to comment Share on other sites More sharing options...
Guest DISCUS Posted August 3, 2004 Share Posted August 3, 2004 1st get rid of the platinum bosch? 4 spark plugsPut in some TR6 NGK plugs Also check your Optispark' date=' what year do you have? Have you done any tunning on the ecm yet? Good luck Mike[/quote'] I have the 95 LT1, Pulled plugs last night and found that two did not appear to be firing at all! Uneven on the others, Wires have all checked out ok, will change to NGK today and see if that helps! Thanks for the input. Quote Link to comment Share on other sites More sharing options...
Guest DISCUS Posted August 3, 2004 Share Posted August 3, 2004 Pulled plugs last night, two show no evidence of proper firing the rest look inconsistent, suspect the plugs at this point. They were autolite double platinum, was considering the bosch but on the advie of others will go with the NGK. Thanks for your input , I did check wires and routing , that seems fine. Yeah...get rid of the platinums. Regular cheap old Champions or NGKs will be better. The LT1 guys over at Z28.com have had fits with the 'pricey' plugs. That hesitation could be any of a number of things. Like Mike suggested' date=' change the opti. 7 times out 10 it is the problem. Might as well replace the water pump while you're in there.... Best place to get suff is from Jason Cromer at Sam Taylor Buick in Florida. BEST PRICES ANYWHERE for LT1 stuff!! http://www.samtaylor.com/html/parts.html Also check your plug wires. Make sure that the routing isn't making them jump spark. If you need new ones, let me know and I will post the MSD part number for teh cut to fit set that has the opti side pre-assembled.[/quote'] Quote Link to comment Share on other sites More sharing options...
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