Vagelis

So i m having a very annoying problem the last few weeks.If i go for a ride and then turn off the car for half and hour for example and try to start it the car misfires for seconds and then goes back to normal.If i press the gas pedal while it misfires check engine light comes on.The scangauge II i have on the car it showed P0300 P0303 P0304 codes.I reseted them and it happened the same again when i pressed the pedal.Last night i left te car to cooldown for 2 hours and when i started the car,while i had my foot on the brake pedal it started misfiring again for seconds and the check engine light was flashing and then became solid.This time code was p0303.

So what we've got....
-Car runs fine except at startups.
-It misfires 90% at hot starts for seconds then it's all normal.
-If i press the gas pedal while it mifires check engine light comes on,if i don't no light will come on.

What i've done so far...
-changed the fuel filter
-cleaned the injectors in a honda dealership with a machine with ultrasounds(???),i doubt that this is the proper cleaning
-changed the coilpacks between them to see if it misfires in another cylinder
-cleaned the iac valve
-checked the spark plugs,they looked good except 3 and 4 which had a very very light white dust on them.

....nothing happened!

My car has a j's racing intake,the air filter looks kinda black but i cleaned it twice!
I also have a j's racing 70rs exhaust,with high flow cat.

Something else i saw on scangauge is that when i try to start the car the volts go down to about 9...with the car running it stays at 14.
Also i filled the tank with coolant to max level,i did 2000km in 10 days while on vacation(very hot weather)and now it's below minimum.No signs of coolant in the dipstick though and car runs staedy at 87-88c degrees.
My next plan is to inspect the valves and adjust them though i dont hear them at all.

What else could it be????

And just an hour ago after a hotstart this happened...

https://www.youtube.com/watch?v=VKD-...ature=youtu.be

PLEASE HELP!!!!!!

slalom44

Do you see any white smoke from your tailpipes on cold startups? Have you also noticed that your A/C isn't as cold?

I'd do a compression test to rule out a leaky head gasket.

Vagelis

No smoke...
I did a compression test while the car was not too hot and it showed 1st-220 2nd-210 3rd-215 and 4th-190.The test began with fourth cylinder and while the car was not too hot.This was the explanation the mechanic gave me about the somehow low commpression on 4th cylinder.He also told me that that it's difficult to be the head gasket because in 2008 (128.000 km) i replaced the complete engine block with a brand new along with the other stuff.Now i have 176.000 km on clock and the car is not driven that hard.

Could a low battery cause that problem?
Is there any possibility a sensor relating to air is reading wrong while it's hot enough in the j's intake chamber,causing that misfire?

Vagelis

Anyone???

AZ-S2000

Thats somewhat of a difference on 4. Valve-guides are pretty known to cause low compression as well. And YES a low battery can definitely cause issues. Replace that or get it charged than give it a try.

Vagelis

The problem still exists...
This time we re-tightened the engine head in case it became loose,but nothing happened.My mechanic said i should wait to see if there is a coolant loss again.If it has we re going to open the motor if not he pointed the alternator.Can ANYONE HELP ME PLEASE,BILLMAN MAYBE???

Vagelis

Also i have to mention sth else.When the problem happens if i shut off the car no matter how many times i ll try to start the car,it will start just fine.My only theory is that after a ride and when the car sits a small amount of pressurized coolant passes in 3rd and 4th cylinder and when i try to start the car it struggles to start and misfires until the coolant evaporates and then it's all fine.What do you think?

slalom44

That might be the problem but that's not how a leaky head gasket acts. And you'd likely see smut in your coolant reservoir as well.

Try swapping injectors to different cylinders.

Eluded

I had a whole bunch of valves bad and that was causing misfires. Hopefully that is not what you're experiencing as one of my cylindes failed the compression test.

Vagelis

i did that already,same thing happened 3rd and 4th.Sorry for my english but what is smut,and how a leaky gasket reacts?