: P0300 - Timing Off



RickyHenry
08-05-08, 05:59 PM
hey all,

I did the head gasket job a while back on my 99 cad sts. Car ran fine after I pulled the engine a 2nd time to get the timing right. Everything was perfect, havn't had a problem since, until last night.

I was driving up about a 1 mile hill and stupid me decided I wanted to test the performance of my sts... at WOT... She did Great!!!!

The problem is, when I got off the freeway a few miles later, I felt the shaking. Then my ses light started blinking frantically staring me in my eye. I turned the a/c vents off, radio off, rolled the windows down and sure enough, sounded like the car was misfiring. It actually sounds and feels similar to when I had to adjust the timing chain on the engine.

Is it possible that my timing was thrown off by my excessive acceleration? Would the chain actually dislocate itself?

All I'm getting is the p0300 code, misfire detected... please tell me I don't have to pull my engine for another go. :thepan:

Submariner409
08-05-08, 06:19 PM
There is no way on earth that a properly timed and tensioned chain drive can jump sprockets/links. The fact that the car ran normally before the WOT is testimony to that.......after the top overhaul did you ever have cause to suspect a misfire or mechanical noise ??

Now you're in the troubleshooting business again.......vacuum leaks, plugs/wires, EGR, fuel delivery systems.

It's going to be something easy........bet on it.

stoveguyy
08-05-08, 10:58 PM
can you explain a little more in detail how your timing was off before? was 1 or more sprockets off? i did my heads too but i really don't think my timing is off. it runs fine off idle.

RickyHenry
08-18-08, 04:19 PM
can you explain a little more in detail how your timing was off before? was 1 or more sprockets off? i did my heads too but i really don't think my timing is off. it runs fine off idle.

My timing was off on an exhaust and an intake, by 1 sprocket each. it was a rough idle and giving p0300 misfire code. I fixed it by pulling the engine again and finding out that I didn't have the sprockets lined up quite right.

My car has been sitting for about 2-3 weeks now as I havn't even had the time to start inspecting it for a fix... but i'll tell you, i'm beginning to miss the sedan. I'll start my diagnosis on Wednesday.

zonie77
08-18-08, 08:04 PM
I would check plugs, wires, and vacuum lines first.

Unless the chains were stretched past the adjuster limits they would not jump.

scl98sts
09-16-08, 08:46 PM
im having the same code i just changed wires and plugs, i was getting a pcm 420 code ,i changed the plugs bcause when i smash the gas it would back fire. can anybody help ?

Ranger
09-16-08, 09:24 PM
Check for a leaking FPR.

Submariner409
09-16-08, 09:36 PM
.....also look at your identical post under P0308 misfires in a thread very close to this one.

scl98sts
09-17-08, 08:25 PM
whats an fpr ?or the thing that might be leaking . today the car decided that it would it would list pcm 300 as history and turn of the ses light, what a nice car ...... but it runs like a big p.o.s. just idleing w/w-out the ac on. during driving not noticable, except smashing the gas from a stand still, it wont back fire all the time but it will hesitate and i notice shifting is a little delayed aswell any other help would be great.

Ranger
09-17-08, 09:15 PM
FPR = Fuel Pressure Regulator. Check the Tech Tips section for a tutorial on how to check it. It's easy and should take all of 5 minutes. Won't even get your hands dirty.

scl98sts
09-18-08, 08:57 PM
update i was driving and ran a scan and now pcm 1527 is in the history.along with his good friend pcm 300