leon phelps

Hello,

Put the engine in the car. been starting it every few months. put a top on it then drove it 10 miles to and 10 miles home from the alignment place.

started it several times and let it warm up.

have not gotten the engine over 200 degrees, so the fans have not come on.

Left the car at a place to get an exhaust put on it. four days later exhaust almost completed.

Picked it up and check engine light was on. drove it home and put the cheapie code reader on it. first error code was n/a, second was p0300.

drove it about another 10 miles to a friends garage. put his snap on code reader on the car. P0300 still coming up with check engine light on. Ran the engine on the diagnostics mode of his scanner and it tells me that #6 misfire, most of the time, with other cylinders reading intermittently (mostly on same side as 6 but with slight variation).

for now, I plan on checking fuel pressure then waiting til dark to make sure no spark jumping from plug wires.

there were some other things the snap on tester told me like, fuel level (not hooked up) etc. I know read o2 sensor was programmed out (I had sent it out to get that done.).

any other suggestions?

ROCNDAV

iTrader: (100)

If it is always #6, then try swapping some stuff. Put the injector on 2, the coil pack on 4, the wire on 8. Does the error change?

leon phelps

thanks. will try that tonight.

had 60 psi at rails, all injectors ohm'd out at 14 or 15.

ls1nova71

iTrader: (4)

Make sure you didn't crack a spark plug or something simple like that. Or it could just be a sticking/clogged fuel injector.

leon phelps

took the injectors off and did a reverse flush to them. two were clogged, all flowing nice now.

guess Ill yank the plugs later today.

is there any way to test coils or plug wires? my wires are new custom Scott ones.

ls1nova71

iTrader: (4)

You can ohm the plug wires, but it's easier to just move the coils and wires and see if the problem follows them.

leon phelps

OK, so I took the wires off. I put my ohmmeter on 2k scale. 5 checked out at .030. Three other ones were at .100, .305, and .223.

I am guessing I have three bad wires. This sound correct?

leon phelps

got my plug wires back from the guy who made them. all ohmed out the same, so we are past that.

while waiting for the plug wires, I ran a compression test on the engine. 185 on all 8. Plugs are bosch iridium ones, gapped at .040.

I still have a noticeable backfire in the exhaust, like the gas is exploding when it leaves the cylinder. I smell nothing out of the ordinary with the exhaust.

I will run the engine tonight in the dark to see if I can see something arcing.

any thoughts what to chase next?

leon phelps

put the new delco iridium plugs in, same result.

drove the car to east coast superchargers. they did an in car tune. popping is gone, check engine light is gone and no codes.

great service. a little pricey $400.

cheaper than replacing the rest of the coils though.

problem was with the fuel trim. seems it was too rich. dialed it back by %25 and it seems fine now. I drove it 50 miles home with no knocks.

OutlawDrifter

iTrader: (9)

headers on a stock engine will make it run rich more often than not. glad you found the issue! i've found that a ground can be your worst enemy in these situations as well.

G-BODY-JAMES

iTrader: (1)

how do you do a reverse flush on injectors?? i just built my complete fuel system from scratch i did flush hoses prior to running car, but i figure i may have a plugged injector from hose cuttings, never had the p0300 code until today when i actually drove the car down the road, prior to today i had only run the car in the garage idled it lots and revved it up etc got a too lean bank 1-2 codes but open headers likely caused em, so ya what is my best way to clean out the injectors? just did an ls3 supercharged swap from camaro to regal i have not changed anything from the way it was other than the cold air intake. i can physically hear the thing miss firing and on the test drive it stumbled hard after 3500 rpm

leon phelps

look on youtube. lots of videos on how its done.

G-BODY-JAMES

iTrader: (1)

thanks and yess lots of vids haha is it common to get this code due to injectors??