ok i have a 2.5L ecotec built to handle up to 20 psi. i ran last sunday and now have a constant misfire in cylinder #3 . i have spark, the injector is pulsing, what else could it be? it happened when i did a run at around 17 psi and now will not idle or drive right. it sounds nasty and has absolutely no acceleration. ive driven it a few time here and there during the week with the engine light flashing. any ideas? thanks for reading.
I could have sworn that I had seen someone post something about his on the JCo site and it had to do with a recall. <br>
JCO WEST - WINDSOR/ESSEX COUNTY REP
Only 3 things make any engine run,
Fuel, Spark and Compression.
If you know your getting air/fuel, and you know you got spark, then it has to be compression. Run a simple compression check on all cylinders and that will give you a heads up on whats going on in the motor. If that specific cylinder is alot lower in compression your rings may have failed due to detination or concievably even worse, you may have a hole in a piston.
I know this because me and a friend installed a turbo on a dodge neon. He ran at to high of a boost and his fuel mixtures were off, needless to say he blew the engine, the car had a rough idle, and exhaust fumes where coming from the dipstick hole when you went to check the oil. Fun stuff.
I'm going to have to agree with renegade. If you have spark and fuel, you probably lost compression. It doesn't matter how solid your engine was built, but if it detonates, from poor fueling or too advanced timing, your engine will be damaged. If the detonation continues, your engine will be destroyed, which is what it sounds like has happened.
Did you have an EGT gauge installed? I would recommend to anyone with an aftermarket turbo, supercharger, or nitrous to get one; it is a far more accurate indicator then a narrow band A/F gauge at detecting a potentially harmful lean condition.
same thing happened to me take off your valve cover and see if your cam follower or roller rocker has come off if so you can put it back on. see if it did the valve will close causing it to misfire and being it has 2 intake and 2 exhaust it will still run but misfire.
i had a problem with mine misfiring and had no acceleration. it ended up being the catalytic converter. i had to take it in and get it replaced.
How in the heck do you have a 2.5L?
I have a built Eco bored .020" which comes out to being 2.3L with stock crank and rod lengths.
In order to get 2.5L, you'd have to bore .040" over and get a longer stroke on the crank with stock length rods.
If you did bore it at all, I wouldn't have boost high on stock GM steel sleeves that have been bored over. The piston walls are way thin as they are and you probrably cracked one if you did bore it out and poured on the boost.
Even when I go boost I will not go over 9PSI because I bored my sleeves .020". On boost engines, the recommend piston wall thickness is .200", .180" is way pushing it and anything thinner than that is asking for trouble and guaranteed problems.
I work at a chevy dealership and had seen an ecotec sleeve get shoved down towards the oil pan. The piston rings caught the edge of the sleeve and shot up, getting stuck under the intake valve, causing a miss in that cylinder. Just someting I thought about when I read that.
I had misfire in 2nd cylinder caused by crappy intake manifold gasket. I guess, it won't hurt to check the gasket.
