s2000maniac

This is my buddy's s2k, 2001 with 187,000 miles. We sent in the injectors to get them cleaned, we put brand new OEM spark plugs, and brand new 04 s2k coil packs, and yet the misfire still continues. This is getting really frustrating, compression test came out fine at 180-190 psi all 4 cylinders. The car runs fine with no power loss, and it seems to mis fire at idle. As soon we drive the misfire seems to go away, and as soon we come to a stop the engine start shaking and the CEL starts flashing. Codes shows cylinder 4 misfire and p1399 Random multiple misfire. Erased the codes and moved the cylinder 4 coil pack to cylinder 1 and drove it again. Check engine light came on after 20 miles and now shows cylinder 4 and cylinder 1 followed by random multiple misfire detected. We also put an OHM resistor on the injectors and they all showed 0.14 ohms. We removed the spark plugs and put brand new ones and the cylinder 4 spark plug seemed to be wet with fuel. Also when we put the injectors back in after they were cleaned, the car would crank 4-5 times before it would start, and it still continues to do that every time we start it. Also we noticed the passenger side motor mount is broken in half, could that somehow cause a misfire? Don't know what else to do....

ronnuke

If the problem moved with the coil pack from cylinder 4 to cylinder 1 I would first suspect that coil pack. Also just cleaning a bad or failing injector will not fix the issue if it is that the injector was not acting up due to being dirty, but instead is going bad, (as I believe is the case in my own car, I have new OEM injectors on the way to arrive Monday) You can determine which injector is bad by moving injectors around, but in my case they have over 200,000 miles on them so I am just replacing them all.

s2000maniac

Well if the coil pack was bad then why cylinder 4 continued to have misfire when I swapped it with cylinder 1 coil pack? Like I said the coil packs are brand new OEM 2004 s2000 coil packs.

Murphg05

have you checked to see if there is spark at the plug? Wet spark plug sounds like it's not firing. Maybe try swapping the injectors from 1 and 4 with 2 and 3. See if that bring the code with it.

ronnuke

Or for that matter why did cylinder 1 now misfire when it did not before moving the coil pack?
It probably is not the coil pack being that it is brand new, that is why I posted what I did about fuel injectors.

s2000maniac

I'm thinking about buying some used fuel injectors off eBay. One other thing I'm thinking the fuel regulator might be playing a role here.

franky

so compression checks out fine and new spark plugs and coil pack, then do a valve adjustment.

s2000maniac

Valve adjustment was the first thing that was done.

realblag

Is the vacuum line to the fpr still hooked up? You might have excessive fuel pressure at idle.

s2000maniac

Yes I even zip tied both ends just make sure that there aren't any leaks.