I have had a "service engine soon" problem for two years now. I had a new motor put in 2 years ago once the used motor was put in the light came on the day I picked it up. Chevy checked the code and it came up with no senser codes just a "missfire" the code changes the cylinders that missfire. They said b.c it was a used motor unless I pay them more money its not their problem. Also the other thing boggling the guys is that the light comes and goes. Last year in PA I had to get the blazer inspected. The guy passed it saying it was only a missfire with no sensers that are bad. However this year the same guy is saying NOPE not this year. He wants a $1000 to start TROUBLESHOOTING. I told him no thanks. So right now I have a few questions. #1 In the state of PA can the truck be passed with a missfire code because there are no sensor id's. #2 Has anyone experienced this problem? #3 Could it be a sensor even though three different computers have checked the code and none came up with a sensor?
Any ideas would help
thanks
mandi

 

First off if Chevy put that motor in then YES they are responsible for codes. it's not legal for them to let a vehicle go that cannot pass emissions. also if they put a motor in it, then it should be in good working order. I can't seem to figure out why Chevy would put in a used motor that they cannot warranty, doesnt sound like a dealership thing to do... something there just doesnt sound right.

as for the code, can you go to an autozone or pep boys and have them read it out to you and then post it here? so we know what the code number is and exact code? also if you can tell me what year, make and model your truck is?

 

It is the truck in my signiature area: 98 Chevy Blazer. The code that comes up is Multiple cylender missfires. I believe it is code 300 or 1300. I fought with Chevy about the issue when it first happened then I dropped the issue b.c it passed inspection last year. Chevy said not their problem because they let me buy a junk yard motor and have it dropped off and installed. Their comeback for me fighting them was ITS A JUNK YARD MOTOR YOU NEVER KNOW WHAT YOUR GOING TO END UP WITH! So here I am today 2 years later. Also the spark plugs and wires and distributor cap and I believe rotor were all replaced AFTER this light issue started and it still comes on. So right now I have a few questions. #1 In the state of PA can the truck be passed with a missfire code because there are no sensor id's. #2 Has anyone experienced this problem? #3 Could it be a sensor even though three different computers have checked the code and none came up with a sensor?
Thanks for the help
Mandi

 

As for the state of PA, different areas of PA have different rules, your best bet is to call a place or two that does inspections and ask them about it. Also Chevy is right on that, I thought the motor came from them but if its a junk yard motor that wasn't rebuilt before it was put in there, its pretty much you take a gamble on what is going on inside that thing. what was the motor out of?

 

Sounds like stuck poppet injectors... And GM has a TSB on this very problem.

Run a search for poppet and sift through the results. You should find a few posts on the issue as well as one or two that have a PN for a new MFI spyder to replace the SCFI spyder (direct replacement). If I had more time now, I would dig up the posts for you.

If you or someone else has the search results and finds the posts that I am referring to, please post a link in here to make it easier for people in the future to find the answers to this same question.