I have been getting a P0304 Cylinder 4 Misfire for the last few weeks. It was first taking a few weeks before it would come back, then a few days, now a few hours after I clear the code. I have changed out spark plugs and swapped the coil packs around and still getting this error. I am a little stumped....Anyone have any suggestions on what I could look at next?
clean maf, do a compression, if that does not fix the problem and compression checks out to be good, then it could be your injectors. what injectors are you running currently?
I am running PE 850cc The plugs that came out looked all fine and they all looked the same as far as the color. I have been through multiple tanks of gas so I dont think it is the gas. I might swap out injectors next week to see if that changes the cylinder of the misfire.
Car does stumble a little and sometimes when it is cold and I dont let it warm up, it stumbles really badly for a few seconds. The misfire code almost always comes on during light throttle or when I am at a light. The car seems to be running perfect when it comes on.
I think Ming **blindfold** was having this exact issue. It ended up being his injectors (PE850's too). Try swapping them around and see what happens.
consensus on nasioc build motor forum is that PE makes junk injectors a lot of people on there are having good success with bosch
I believe so, I'd have to double check though. drop in, correct impedance edit: they are top feed, high impedance. can handle 100# static pressure, and flow 1500-1600cc/min at that pressure http://forums.nasioc.com/forums/showthread.php?t=1702099
Thanks for the info Nicad...too bad they are top feeds...I have no desire to switch over to Top Feeds until the new motor gets in.
The MAF sensor will effect ALL cylinders, You need to look at things that are specific to that cylinder. As many have already mentioned, it is probably an issue with that injector. If you feel like troubleshooting it, first check for injector pulse (using a noid light), this will tell you wether or not it is getting a good signal from the controller. If the pulse signal is good, then move on to checking continuity and resistance across the leads on the injector. If both check out, then it is a spray issue...like it is clogged up and the spray pattern is bad. However, seeing as how the frequency of the problem has been getting shorter and shorter between failures...I would lean more towards an electrical issue.
I hate to say it but if it was any other cylinder than 4 or even several cylinders that were experiencing a misfire I would venture that it was the injectors, but since its always #4 I fear the worst. I would certainly do a compression check. If you need a gauge I have one you can use or you can swing by next week and I'll help you run the test.
If you are going to switch later then you might as well switch now the Bosch 1000cc injectors are really nice.
Ok, so I have swaped injectors around. The injector on #4 was really dirty on top and around the injector. Sprayed it with carb cleaner and put it into #1. Reset ecu and I should know sometime today if the CEL comes back on and if it moved with the injector. If it is the injector, I think I might want to go with Top feeds. DOes anyone know exactly what all I would need to convert to Top Feeds? Would it just be the rails, TGVs, and injectors?
Well you would need fuel rails for sure since they feed from the top of the injector and not the side of the injoector.
Why do you want to do all of that extra work? Or are you getting fueling out of the way while you are at it for the bigger billet turbo you are talking about?
Well if it is indeed an injector issue, I would rather just switch over to topfeed and be done with it. I do not want to buy another set of sidefeed injectors.
So far no misfire. It has been 3 days and it usually misfires after the 2nd day after an ecu reset. If I get another misfire, I will go ahead and move to a topfeed setup with the 1000CC Bosch injectors.
Maybe it was that dirty injector after all! Woot for not having to spend more money! Btw I usually throw in a bottle of injector cleaner every 5 gas tanks or so. I noticed in the past the car wouldn't run as smooth after 10 gas tanks or so and doing the cleaner solved that issue! I guess my modded stockers are easy to get dirty thanks to gas stations not being that clean to begin with.
I personally use Gumout regane or Amsoil PI (nothing else) as an injector cleaner Once a year i do an injector clean and intake manifold clean
Oh it is every BIT as stable. You just have to make sure you know when they are switching blends and have the appropriate map ready. IE winter tune, summer, spring. The nice part is it is so resistant to detonation that even if you run a bit lean, your chances of messing something up are WAY down compared to gasoline. Same thing would apply to meth injection or water injection...you better be watching to make sure that thing does not fail or you could fubar a motor quick!! Pump failure, nozzle blockage, leak...all kinds of possibilities. At least E85 still has the detonation resistance no matter if it is summer, winter or spring fuel!
Meh 4 tunes? Expensive. And on my meth failing I'm covered. I have fail safe. My WG pressure is below where I even start spraying meth full blast. Priming at 12 full blast at 17. Fail safe monitors pressure and flow. If it exceeds 135 psi or falls under 90 psi it triggers. If it doesn't detect 100 psi in milliseconds it triggers. As with everything I try to do it right. But I'm toying with e85. 3 more stations have it here since Jan 2009 so maybe next year I'll try it out.
It depends how close to the edge you have it tuned. A motor tuned on the edge with E85 is just as likely to detonate as 93 octane. Also as far as Methanol being stable I'm not sure but I would imagine that it absorbs water at about the same rate as Methanol and if thats the case its not really what I would call a stable fuel.
Oh, it is pretty darn stable. It does absorb water, but then again so does the 93 you get at the pump. I have not seen any real variance from day to day, tank to tank, even letting it sit for a week. The only changes I see are when they switch blends. This is after around 15k miles on the stuff now! And the fact is even if it is tuned pretty close, it is HARD to make a motor knock on E85. You can actually advance past MBT without knocking. And again...no matter which blend out are on it is still around 100 octance and has some serious knock resistance from the fuel itself and the cooling abilities of alcohol! As for the various tunes, it is just minor adjustments...not a big deal. It's not like you are changing everything unless you are tuned to the ragged edge. I try to keep things safe and reasonable. But this is about the misfire, not a E85 debate I was merely pointing out the cleaning abilities of alcohol on the engine!
You can get a good look at a steak by shoving your head up a bulls ass.... I wouldn't say there is anything hard about making a car knock despite what fuel is in it.
CEL came back on Friday....Good news is that it is misfiring with the same injector so now it is being dtected in Cylinder 1. Now that I know it is an oinjector problem, should I just buy some DW 850 Sidefeeds and get Doug to touch up the tune or go with the TOpfeed setup that would cost me an ass load of money? Will the 150CC really benefit me in the future going to 1000CC Top Feeds? I dont even know if my Walbro will keep up witht hem and dont really want to try and get a bigger pump in my car.
my 255 seems to be keeping up alright so far with 930's in. I think 1100+ and turning up your Fuel pressure wil require new pump set up, so 1k should be okay for 93 and race. My 2cents, i am sure Mike or Matt will chime in.
Go topfeed..those bosch injectors keep getting good reviews! Or just replace the one injector and call it a day.
I can't replace just one injector. I would have to buy at least two injectors and I do not want to buy more PE stuff. So I have a line on a set of used DW850 for around $350....Another $80 for cleaning and 1/2 hour tuning brings the total to about $550 or so..... The top feed setup would cost $450 for the injectors, $150 for TGV, $350 for fuel rails, At least 2 hours for tuning, plus labor to install everything. That is looking closer to $1500 after all said and done. Do you guys REALLY think it is worth the extra $1k for a top feed setup? I would love to hear from Doug and Matt on this.