Re: 97 5.7 horror tech random misfire 12-18-04 07:13 AM - Post# 577461 In response to mikhalljr I have a 98 Tahoe, 5.7L. For a year and a half, I did the tune up & injector cleaning thingy to fix the "multiple misfire" or the "#6 misfire" code that would occur under load (steep grades-towing).
Dec 22, 2015 · Stall, Misfire case study: Pontiac Grand Prix 3.8 - Duration: 12:34. Pine Hollow Auto Diagnostics 47,758 views It'd only mis-fire while towing and going up hill, so under heavy load 40-50% throttle 3rd gear, other than that it ran great. What other mechanics have found is that the valve guides are a little too tight and that can cause the valve to hang open, causing the mis. 1999 Pontiac Grand Prix Misfire under load. This is a discussion on 1999 Pontiac Grand Prix Misfire under load within the Domestics and Foreigns forums, part of the Vehicle Specific category; I can't figure out what's causing a random misfire under load in my GP. Misfire under load,ils, - I give. My 1999 grand prix gtp hesitates on acceleration when boost guage kicks in i replaced plugs and plug wires and the mass air flow sensor also cleaned the throttle body out its throwing multiple misfire 4 Answers. my 1999 Pontiac grand prix gtp is running poorly when boost kicks in...it throws multiple misfire codes and nothing else..i replaced the plugs and ...
Typically an engine misfire under load, will be a problem with the ignition system, while low engine speed problems will be a vacuum, fuel management or compression issue. When retrieving trouble codes, only consider related codes to a specific misfire problem, like an ignition coil failure code. Feb 05, 2010 · I am logging intermittent misfires on the even-numbered cylinders, mainly #4 and #6. Not enough to turn on the Check Engine light, but I can see them logging in the computer by using my AutoTap and laptop. It doesn't seem to occur when driving down the road, only when testing with no load in the driveway for some reason.
I have a 99 grand prix it runs fine most of the time but when i give it lots of gas it does not wanna go it ... The fact that it misfires under severe load (i.e ... Typically an engine misfire under load, will be a problem with the ignition system, while low engine speed problems will be a vacuum, fuel management or compression issue. When retrieving trouble codes, only consider related codes to a specific misfire problem, like an ignition coil failure code. 2004 Pontiac Grand Prix Questions Get answers to your auto repair and car questions. Ask a mechanic for help and get back on the road. Mar 29, 2012 · 2002 pontiac grand prix hesitation/ stumble on moderate acceleration and/or up hill . wide open throttle it goes just fine. no codes. idles just fine. no other symptoms. just bought car a couple weeks ago seems to be increasing in frequency and intensity.