maxinout93

I have an 02 I 35 gradually its been acting up the last 3 weeks at startup I get a good start but then it runs ruff as it idles down and the idle speed fluctuates. Sometimes it starts fine and doesn't miss at idle or go putt putt at idle or in park. Once I start driving the miss seems to disappear until I come to a stop. Ive changed the spark plug and coil and replaced the injector with a used one and it will run fine a little while then the miss comes back. Im stumped ive removed the intake manifold at least 4 times changing fuel injectors and o-rings. The car drives good for the most part. I did get a code for po301 but Changing the coil got rid of that.

Derrick2k2SE

iTrader: (3)

I would check all over for vacuum leaks. At least to rule that out. The rough idle but smooth running is one sign of a vacuum leak.

maxinout93

You may be right because I can drive up and down the interstate at 70 plus mph or any other speed and the car goes and drives like normal its only while stopped or idle it runs ruff. I do hear an ailing leak somewhere but I can't pinpoint it. Ive also never replaced intake manifold gasketeeither.

mclasser

Put some water in a spray bottle and spritz around the hoses and manifolds. If the idle changes, you found the leak.

maxinout93

thanks man sometimes this car drives me crazy when it does not run right. And to think i was gonna purchase another I-35 that had both p0420 and po430 plus 3 other codes with over 200K on the dash smh

Derrick2k2SE

iTrader: (3)

Good advice. I like to use brake parts cleaner in a spray can. The slightest bit of that in a vacuum leak will really make the revs jump. With the little stick you can get it anywhere.

maxinout93

I dont know what's going on here. I replacedd the spark plug in cylinder 3 and pulled it out again to check it. I replaced the coil twice. And the original coil barley fired on that cylinder, at times of the misfire it would not fire. But switching it to a different cylinder it fired/ while doing the coil test. Is there something that controls the ignition coil firing like a condenser like the 5 gen has? What would cause the coil to not fire in one cylinder and work in another? I changed the injector on that cylinder with another used one. Sometimes the car runs and starts fine then starting again it will misfire badly until given more gas. Took it by another shop today I turned it off and started it back up only for it to go putt putt and misfire while the guy was looking at it. He said if the fuel injector is not spraying enough fuel at times it may cause the misfire. Im confused as what to do next. I put in some Lucas fuel injector cleaner to see if it helps. Most times the problem is after the car has warmed up is when it occurs and mainly felt at idle or in park.

maxinout93

I dont know what's going on here. I replacedd the spark plug in cylinder 3 and pulled it out again to check it. I replaced the coil twice. And the original coil barley fired on that cylinder, at times of the misfire it would not fire. But switching it to a different cylinder it fired/ while doing the coil test. Is there something that controls the ignition coil firing like a condenser like the 5 gen has? What would cause the coil to not fire in one cylinder and work in another? I changed the injector on that cylinder with another used one. Sometimes the car runs and starts fine then starting again it will misfire badly until given more gas

TSelanne

iTrader: (2)

Not always a shared opinion around here......but now when I get any of the p300 codes and it's a coil problem, I replace all 6 coils and plugs. After 3 maximas I've learned that once the coils start going bad, IMHO replacing one of them is just a waiting game as the others go bad soon after the good one gets installed. Just much easier to do them all at once and problem solved. Only oem coils.

Bow Tie Guy

these cars are notorious for having corroded connectors in a wet winter envitonment, I use aerokroil, a tooth brush, and compressed air to clean the injector and coil connectors

maxinout93

Thanks for the replies guys I went to pull a part today to grab a spare coil harness for cylinder 1-3-5. since the misfire occurs on the same cylinder but not all the time. So I get back in my car I get a ruff start. So then po300 pops up as well as p010000216mo camshaft position timing over advanced bank 2. ? Which one is bank 2 these are 2 new codes I haven't seen until today

maxinout93

well the misfire occurs only when warmed up. I replaced the injector/coil and plug all on that cylinder that was misfiring. Still same thing no change. I only feel it at idle and park and its starting to drive me nuts! Even though all the part are used except the spark plug ive swapped injectors 3 times on the same cylinder so they all cant be bad. I did go by a shop that one mechanic said one of the rings or a valve could be bad ect ect but id have to leave it there for a day for them to diagnose smh. Im thinking most likely its gonna be an expensive fix as i still get air bubbles in my overflow tank and no heat at idle still, but the car still runs up and down the interstatate with no trouble. Im thinking how much longer will it run.

Bow Tie Guy

sounds like you've answered your own question

#3 may be getting wet is there combustion gas in the cooling system?
you can use test strips or a block and head gasket tester to find out
bubbles in the reservoir is a good tell tale

ps I've had stellar results with a product called "seal up" from motor purr

http://motorpurr.com/metallic-seal-up/

maxinout93

So have you experienced this before on this engine? Someone gave me a theory similar to what u just said that once car warms up coolant may be seeping into that cylinder. May be the reason why when I bought this car there was stop leak in the coolant lines? that seems like the only other solution at this point I dont want to have to install another motor if I can still save this one.

Bow Tie Guy

I've not used this "aerobic" head gasket sealer in a V6. I had my results on an L28E 280z. This product is basically a blob of colagulate that finds the leak do the presence of air or oxygen, when subjected to air the product hardens and fills the void in the headgasket

if you have coolant in the oil, this isn't the answer. look at the bottom of your oil cap do you see the milky way, no not the candy bar


ps a blown head gasket is a common repair. no need to replace the motor

maxinout93

No the head gasket isnt blown ive confirmed that with several shops, but what some have said it may have a small pinhole leak in the gasket that may seep coolant in once the car is warmed up. Most of the time the car runs fine I only feel the skip when i start the car back up once warmed up, give it some gas and it smooths out. They suggested i pour something in there to buy some time but i cant remember exactly what it was. I may just take it to a shop and let them do a diagnosis as ive done most of what i know to do as far as changiing the coil/ spark plug which the original spark plug that came out of that cylinder was cracked, and gap was large.

maxinout93

Well so far the code seems to be gone I reset the ecu yesterday. Starts up strong each time but now the idle speed is around 8-900 when coming to a stop.


Update: well so far so good and 1000 miles later fingers crossed the po303 has not come back on since.

PopularWithVertigo

I'm having a similar problem with my 2003. It cold starts fine, but idles very low, rough and weak. I can drive it fine to a destination, but after shutting it off and cranking it again a few minutes later, it will turn over and then quickly putter down to a stall. I recently did an alternator swap, and I don't know if that's involved here, because it was doing this occasionally but not often, before the alternator became a distinct issue and had to change. Battery voltage is normal and the electrical is fine so far as I can tell.

I've found though that if I lightly depress the accelerator immediately after cranking, and maintain a slightly higher RPM for about 20 seconds, the engine will eventually maintain idle. When I get the time I'm gonna look at the spark plugs/coils, but my first thought was injectors, which is something I've never dealt with before (total amateur here). It's approaching 200k but I really don't want to go through the process of getting a new car, and I've grown attached to this monster. Anyone have thoughts on this issue?