Engine Light and Hold light flashing

[zero_cool09]

So I have read another post on this before and see that there is probably a misfire, either from a bad coil pack, wire or spark plug.

But the engine doesn't seem to be having a misfire (or it doesn't happen when idle).

Some background on this car, its a 2005 and the guy I bought it from had the car sitting for about one year. He had replaced the timing belt, head gasket and a couple of other things.

I have cleared the codes by unplugging the battery for 15 minutes and this car does throw the lights up again right away. I've also noticed that 3 of the 4 plug wires have been replaced with blue ngk wires, while the 4th looks original.

I just went out on my lunch hour and bought an obd2 reader, going to see what specific codes are coming up.

Was wondering if there is anything I am missing from this troubleshooting list. Thanks!

[avguy]

Compression and/or leak down test. With the history you posted, IMO you should do one or both of those first, in order to confirm what shape the engine is internally.

[zero_cool09]

Compression and/or leak down test. With the history you posted, IMO you should do one or both of those first, in order to confirm what shape the engine is internally.

I guess I should go out and buy a compression tester. I will wait to see what the codes are first, but I imagine its going to be p03xx

[zero_cool09]

So I got an OBD2 reader. Code is p0300 just like I thought. Going to be replacing the first cyclinder spark plug as when I pulled all the plugs out that seemed to be the one that looked worse for wear, there was build up of oil I'm guessing because it wasn't firing.

I did the misting of the coil and wires trick, and didn't get any arcing just to check that they were not the issue. Although I know thats not a for sure way of knowing. I just didn't feel comfortable with pulling the spark plug wires off the coil while it was running.

[zero_cool09]

The spark plug wires have been replaced. I talked to the guy I bought it off who is a mechanic and he believes there is a vacuum leak. But the only code I ever got was p0300 and my engine light and hold light still are flashing.

Any ideas?

[zero_cool09]

So I have done everything, compression tests, looked for vacuum leaks and replaced coil pack, sparks plugs and spark plug wires. Still have this problem and I am stuck. Currently just tricking the computer so it will shift into 4th when I need it. (I have a obd2 reader to clear the p0300 code plugged in as I drive)

[petrified.rabbit]

the p0300 code is just a general misfire code. you do not have a p0301, p0302, p0303 or p0304 too, do you?
That would help narrow it down if you did.

Just a few possibilities...

Are the plug wires on the correct way? i know that sounds stupid but it is a "traditional" waste spark and can run backwards..
but also be considered a misfire. Also if you have the wrong plugs in, it could also trigger this issue. any power loss issues?

A big indicator that it might still the coil pack is the hold light.. But it could be a ground issue as well. Check your transmission/engine ground strap to make sure they were hooked up with the head gasket change. If bought a coil pack, its hard to say try another. But the signal for the hold light I think you would get a code for too do you have one?

Another way to for the engine to miss is no fuel, if the car sat a while like you said you might need to clean out the injectors.
have you done your other maintenance like air filter, oil, etc on time? Fuel filter?

[zero_cool09]

Just the p0300 code, which is stored and pending when I check the codes, so its on going as the car runs.

I'm pretty sure the wires are on correctly, considering the lengths. I didn't reference a diagram or anything though.

Which are the correct plugs, I didn't replace the plugs myself, they were done at the time of purchase from the guy who sold me the car.

I don't have any power loss, it accelerates in the lower gears fairly easy.

With checking the ground, how should I go about that? Im not sure where its located to be honest.

I haven't changed air filter, oil, or a fuel filter. But looking at the air filter it is a little dirty. I should do these things then too.

I appreciate your detailed response!

[zero_cool09]

So interesting development! I have had the lights not flashing for about a day. But they came back on when my girlfriend filled the car with gas. I made sure the cap was back on properly. But it seems this issue is arising when the car is refilled with gas.

[zero_cool09]

The lights consistently do not come on when the car is around 1/8 of a tank of gas or less. So I going to try and clean out the fuel pump and filter and see what that does.