Codes - P0303 & P0304
03-20-2015, 10:47 AM
#21
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sorry, i dont know if you found your solution to the problem or not yet, but i had the same issue with these codes before. Turns out, i needed to do a valve adjustment and everything was fine after that. I bought new spark plugs, new injectors, new coils, clean everything and it was useless. Check and do valve adjustments, it's your best bet.
03-20-2015, 11:37 AM
#22
coils r ez 2 test get an adjustable spark tester for $8. then hook up a fuel pressure tester this will tell you if the fuel pump, regulator are working. also can test the injectors with this tool. I can explain latter. could also still be a base engine concern you will need to do a compression test for that. just take it on step at a time. injectors don't go bad often but could be missing power or ground you can use a test light to test for this or a gel194 bulb hooked into the connector.
03-21-2015, 02:08 PM
#23
Don't overlook the obvious.If new coils fixed the problem for 8 weeks, and the vehicle started acting up in the same manner again, I would have immediately gotten new coil packs. Overlooking the dependent variable can be expensive both monetarily and chronologically. I'm not testifying this will fix your vehicle, however I'm simply stating my opinion based on observation of information and experience.
Short story: Once got gas, while running (weak battery), as soon as I left the pump I noticed the vehicle bogged down. Got home, would start and bog and die. I started checking connectors, found screw came out of fuel pulsation, contemplating low power to ecu, maybe fuel pump getting weak, fpr, contemplating all these components from advice. I used battery to wire fuel pump up directly, pumped all gas out (full tank), went and got fresh gas and fired it up after about three cranks. For over a week I jumped through hoops overlooking what I knew was the dependent variable. If coils fixed it, get new coils. Maybe something is causing the coils to go bad.
Short story: Once got gas, while running (weak battery), as soon as I left the pump I noticed the vehicle bogged down. Got home, would start and bog and die. I started checking connectors, found screw came out of fuel pulsation, contemplating low power to ecu, maybe fuel pump getting weak, fpr, contemplating all these components from advice. I used battery to wire fuel pump up directly, pumped all gas out (full tank), went and got fresh gas and fired it up after about three cranks. For over a week I jumped through hoops overlooking what I knew was the dependent variable. If coils fixed it, get new coils. Maybe something is causing the coils to go bad.
For everyone else; after checking and making some small adjustments to some of the intake valves, the problem is still present. I also threw some new plugs in there to rule that out.
03-21-2015, 03:34 PM
#24
After doing an ohm test on the injectors, they all fall within range (14.0-14.2). I also did a 'high tech' screw driver test. All seem to be firing consistently. I've read this doesn't rule out a clogging or worn out injector but at least I know the electrical portion of everything is working as intended.
I snapped the bit off while tapping my fuel rail, which was discouraging... so it's almost sledge hammer time.
Does anyone know any other diagnostics I can do before purchasing a fuel pump, 4 injectors, or 4 new coil packs?
I snapped the bit off while tapping my fuel rail, which was discouraging... so it's almost sledge hammer time.
Does anyone know any other diagnostics I can do before purchasing a fuel pump, 4 injectors, or 4 new coil packs?
03-21-2015, 03:39 PM
#25
Find a buddy and borrow his coil packs for a test and see if that fixes it before ordering more. I am willing to bet those aftermarket coils are your culprit. Only go with OEM Denso coils. I had bought a set of cheaper aftermarket coils to keep on hand for testing purposes only and had one fail on its first drive out. Definitely wouldnt run them full time, that's for sure.
03-21-2015, 03:56 PM
#26
Find a buddy and borrow his coil packs for a test and see if that fixes it before ordering more. I am willing to bet those aftermarket coils are your culprit. Only go with OEM Denso coils. I had bought a set of cheaper aftermarket coils to keep on hand for testing purposes only and had one fail on its first drive out. Definitely wouldnt run them full time, that's for sure.
I just pulled the line off the fpr and nothing is coming out while the car's on. Couple this with the fact that, even while warm, the car is running (based on smell) extremely rich, I think the plugs aren't firing properly and since I just replace them with new ones, it only makes sense they are simply not firing/sparking on command.
Thanks for your help. Have a great weekend. I will re-attack this tomorrow.
Matt
03-22-2015, 01:41 PM
#27
Alright. I think I'm in the clear. No codes and it idles properly now.
After doing the valve adjustment yesterday I let it code and cleared it 3 times. Each time resulting in cyl1 misfires. This was a step in the right direction as I was getting 1, 3, and 4's prior. It seems as if the valve adjustment fixed 3 and 4 but not 1. Regardless I had something to work with now...
Luckily, and to the dismay of my wife, I rarely throw anything away. This time it paid off. I swapped cyl 1's coil pack with one of my known two original packs. Fired it up. No misfire. So it seems one of the four packs I bought as replacements is bad. To verify, I put the faulty (new) pack in cyl 2, with the known good pack in cyl1. Cleared the code. Let it code again. Now I had a cyl2 misfire.
So in closing, I think there were multiple things going on here. cyl3 and cyl4's intake valves were slightly out of spec (loose) as my .254mm feeler went easily in. I think this was causing the misfires on cyl3 and cly4. And obviously, the bad (new) coil pack was causing cyl1's misfire.
As of right now I have 3 working 04-05 model (30520-RRA-007) and 1 00-03 model (30520-PCX-007). I'm not a huge fan of this and with 1 of the ebay'd RRA's having already failed, I think I might just get 4 new RRA's from Majestic and be done with it.
Thoughts?
Thanks for all the help everyone,
Matt
After doing the valve adjustment yesterday I let it code and cleared it 3 times. Each time resulting in cyl1 misfires. This was a step in the right direction as I was getting 1, 3, and 4's prior. It seems as if the valve adjustment fixed 3 and 4 but not 1. Regardless I had something to work with now...
Luckily, and to the dismay of my wife, I rarely throw anything away. This time it paid off. I swapped cyl 1's coil pack with one of my known two original packs. Fired it up. No misfire. So it seems one of the four packs I bought as replacements is bad. To verify, I put the faulty (new) pack in cyl 2, with the known good pack in cyl1. Cleared the code. Let it code again. Now I had a cyl2 misfire.
So in closing, I think there were multiple things going on here. cyl3 and cyl4's intake valves were slightly out of spec (loose) as my .254mm feeler went easily in. I think this was causing the misfires on cyl3 and cly4. And obviously, the bad (new) coil pack was causing cyl1's misfire.
As of right now I have 3 working 04-05 model (30520-RRA-007) and 1 00-03 model (30520-PCX-007). I'm not a huge fan of this and with 1 of the ebay'd RRA's having already failed, I think I might just get 4 new RRA's from Majestic and be done with it.
Thoughts?
Thanks for all the help everyone,
Matt
04-06-2015, 03:34 AM
#28
This is becoming a bit ridiculous at this point.
Started the car up this morning and I immediately knew something was wrong. I turned it off right as the CEL came on so I don't have the actual codes but I'm fairly certain they're the same as before.
The seller sent me 4 new coils which I installed on Wednesday. They worked great. Drive the car Thursday and Friday. Monday, fire it up and this.
Started the car up this morning and I immediately knew something was wrong. I turned it off right as the CEL came on so I don't have the actual codes but I'm fairly certain they're the same as before.
The seller sent me 4 new coils which I installed on Wednesday. They worked great. Drive the car Thursday and Friday. Monday, fire it up and this.
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