Mcoffey24
TYF Newbie
Hi all, I'm new to this forum and want to share my recent problem with my 98 Tahoe. I have had the Tahoe for about 3 years now and it has been an awesome truck when it runs! I had # 7 injector quit on me about this time last year so I replaced it and have had no problems until this month. I started the truck so I could leave and I had a dead miss for about 30 seconds and it went away. I drove the truck for about 2 weeks and it started missing again but this time did not clean itself up. The SES light came on so I checked the code and it was a cylinder 2 misfire. After checking spark I knew it was a fuel issue so I stopped by the auto parts store and got a injector and a intake seal kit. After I got everything back together the truck was running worse then it ever has and the code I had now was p0300 random multiple cylinder misfire. I thought the problem was a vacuum leak on the intake where it seals around the injection unit so I pulled it apart and the o ring broke. I got a new o ring and put everything back together again and had the same problem! At that point I started checking everything that could have anything to do with a misfire and found that the cylinders that had a misfire were moving around so then I was really stumped. That had me thinking maybe the cap and rotor were weak or firing intermittently so I replaced the cap rotor plugs and wires fired it up and still had the same problem. Checked fuel pressure on the rail and everything was reading right where it should be. I started thinking back and I had just filled the gas tank a day before all this started so I wanted to see what the fuel filter looked like. I dumped a bunch of black crap out of the filter so I started looking into a fuel issue again. I pulled the TB off so I could get to # 3 injector (it was a cylinder with a misfire) without pulling the intake off again. With some 45 needle nose pliers I was able to pull the injector up to see if it would spray while cranking the engine. It did not so I pulled number 1 to see if it would and it was! So now I knew this is a fuel problem and after reading about many people having problems with the SFI fuel system I decided to replace all the injectors and pressure regulator to a MFI setup. Got everything back together and finally it was running better then it ever has! Looking back on this I blame this problem on bad maintenance on my part. I bought the truck with 70,000 miles on it and it now has 135,000 miles on it and I have only replaced the fuel filter once. From now on I will definitely be more concerned about changing the filter and using injector cleaner. I hope this can help someone avoid or identify this problem so you dont end up throwing parts at the problem like I did.
