P0300 GREAT! Random multi misfire

[chevy3504me]

I bought another Camaro,1998, last week with hopes to fix it. The guy seemed very honest but didnt know very much about cars. He said all it needed was a water pump...Why would you sell your "baby" if thats all it needs? Im guessing there is more. It sounded fine when he started it up.

I get it home, install the water pump, put clean water in (Flush it a few times before I add antifreeze) it runs like chit. Hook up the scanner, 6 codes come up. I erase them and do a few small things and now only one....the dreaded P0300.

It needs plugs and wires any way so my feelings wont be hurt if this doesnt fix it but it would really be nice if it did fix it. Nope! One of the coils has a crack, needs to be replaced too. Nope!

All of the coils spark but they can still be bad right? Today Im going to swap my ICM and other coils from another Camaro and see if that does anything.

It shakes a little, Feels fine when its on the road but idling it shakes, light flashes and it sound like its gargling listerine. The cat is rattleing too. Im propbably going to cut that off today as well.

Wish I had hp tuners

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

This is pretty cool, I may try to get in touch with him


http://www.fullthrottlev6.com/forums...-about-it-here!

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

New plugs and wires, tested the coils and ICM-both good. I sprayed wd 40 every where and cannot find any leaks.

The engine makes the gargling sound with the belt on or off so Its not a pulley

hmmmmm...what do do... it drives fine but at idle is sounds like ****. I didnt cut the cat off yet.

[thebeewantsboost]

Re: P0300 GREAT! Random multi misfire

was the gargling there before you did the waterpump job? gargling sounds like air in the coolant. how long has it been sitting it could be bad gas. have you made sure it doesn't have bad head gaskets? coolant in the oil or the opposite? is it overheating still?

[bigbrian442]

Re: P0300 GREAT! Random multi misfire

Might want to clean the MAF.

[Blizzard242]

Re: P0300 GREAT! Random multi misfire

What year is this car?

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

Might want to clean the MAF.

I sprayed it but it may be bad or dirty still. When I took the air intake off, the screen looked like it had been tampered with, cracked. Maybe an animal? Also looked like a puddle of oil at the bottom of the screen....on the inside. looked like blowby but since ive cleanded it nothing else has collected there.

I would test it but this car killed my meter. Guess Ill buy another.

What year is this car?

Sorry guys Its a 1998

[Blizzard242]

Re: P0300 GREAT! Random multi misfire

I sprayed it but it may be bad or dirty still. When I took the air intake off, the screen looked like it had been tampered with, cracked. Maybe an animal? Also looked like a puddle of oil at the bottom of the screen....on the inside. looked like blowby but since ive cleanded it nothing else has collected there.

I would test it but this car killed my meter. Guess Ill buy another.







Sorry guys Its a 1998

I'm guessing it has the angled TB. How bad is that screen? I know my 98 would absolutely not run without the screen in there to straighten the airflow so if yours is damaged it may be throwing off your MAF readings.

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

was the gargling there before you did the waterpump job? gargling sounds like air in the coolant. how long has it been sitting it could be bad gas. have you made sure it doesn't have bad head gaskets? coolant in the oil or the opposite? is it overheating still?

Sorry I didnt notice your post (same avatar)

The gargling was there before and after. I also removed the belt and the gargling stayed. Possibly air, thats what it sounds like to me but not sure. I havent changed the T-stat yet but I have a 160 for it. I dont know how long it sat the guy said 2 weeks before I bought it. I did put fresh gas in it and drove it down the street..only once. I also need to install a new rear brake hose. The one on it leaks so I cant realy drive it around yet.

There is no coolant in the oil or oil in the coolant. When I change the brake hose I can drive it up and down my street and get it warmed up

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

I'm guessing it has the angled TB. How bad is that screen? I know my 98 would absolutely not run without the screen in there to straighten the airflow so if yours is damaged it may be throwing off your MAF readings.

sum beach. Ye its the chit piece angled one. I have two 98s and a 2000. The 2000 is so much easier to work on and looks much better under the hood.

The screen looks cracked. Ill look at it again and try to get pics. May be 3 days from now but ill try. I wanted to take it off but I didnt want to be the a s s hole that broke the screen lol

When yours wouldnt run with out the screen, had it been tuned? I would think the MAF would throw another code? I know they arent perfect and anything is possible

[Blizzard242]

Re: P0300 GREAT! Random multi misfire

I was just done installing a turbo, trying to tune it, but I just couldn't get it to run decent at idle no matter what I did. Then it dawned on me, the MAF screen. I had removed it when I pulled apart my TB to block off the PCV and didn't remember putting it back in. I found it in my garage, so I put it back in and even without tuning it any further it ran exponentially better.

I use just 2 paper clips to remove that retainer spring, unless you have a proper tool for it. The screen should just come right out after you get that out.

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

lUCKY! I removed the retainer clip to get some of the trash out when cleaning. I could see the lower part of the screen was out of place (bent looking) and a piece of metal sticking out. I pushed it back in. It doesnt look like it would come out in one piece. Next time Ill do it out side in the daylight.

These things cant be purchased any where can they? I may be able to find one at the junk yard...hmmm

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

I need to check my injectors

[timthescarred]

Re: P0300 GREAT! Random multi misfire

Oil around the MAF screen usually means your PCV needs replaced. Also Check your Fuel Pressure. My 2000 had a p0300 that mostly showed up at idle and not so bad above, after going through coil packs, ICM, plugs, wires, and even replacing an injector, turned out to be that the FPR had gone bad, so the MAP was sucking gas into the vacuum line. You can start the car, then pull the vacuum line that goes from the FPR to the MAP off, if there is any gas there (i.e. if its wet) then you need a new FPR.

[chevy3504me]

Re: P0300 GREAT! Random multi misfire

AHH, Thanks. Ill have time to mess with it tomorrow. Im goint to test the FPR first, then CrankPS then CamPS

Then replace the rear brake line

Then Ill remove the cat