misfire in #4 cylinder.
Posted 13 July 2002 - 09:47 AM
I have changed my plugs and my wires are still good.I have Vi Teck wires in!!
Random i think your experiencing the same Misfires as i am and was wondering if your problem has been rectified!! :confused: :confused:
Any help would be appreciated!!
Posted 13 July 2002 - 07:00 PM
The tuning is the problem. The ECU *guesses* which cylinder is mis-firing based off the crank and cam sensor, and when the knock sensor goes off. It could be a late, post combustion event in #1 caused by running rich and the waste spark, or it could be pre-ignition in #3, but the ECU blames #4.
I get misfires on all 4 cylinders, and also a *random misfire*. No it's not *mine*, it means the ECU can't tell which cylinder is phucked up, so it just gives a *random misfire* error.
Tuning is the only fix (short of ripping the turbo off). If you drive hard, often, you'll aquire misfires on all the cylinders. Mine usually happens on #1, but the other 3 cylinders get their share, with the occasional *random* misfire.
The Supercharged engine gets them too. I blame it on overfueling, and the waste spark igition system. (I may be 100% wrong, but that's my semi-educated guess).
Posted 13 July 2002 - 09:57 PM
just a thought i might be wronge :confused:
One question whats the colour of the carbon on #4
reason i ask is if you have to keep replacing #4 plug maybe the fuel from the 5th injector isnt mixing properly and making it to the furthest cylinder causing it to run lean and eat the plug due to heat.
Posted 14 July 2002 - 04:47 AM
Jon- I know you said money was tight right now, but if/when you get a chance, consider removing the 5th injector, going to a set of 4 350cc or 440cc injectors, and then having the uni-chip retuned to accomodate the injector size change. It is capable of doing that.
Posted 14 July 2002 - 05:08 AM
I pulled my plugs to see how they all were and i was well surprised they were all exactly as they should be dark brown ring of carbon on the rim and going lighter to the very clean tip. Only an indication i know but it says to me that the regulator is set about right. I just need to get the programme toned down in the chip at top end if i remember right its set to about +50 at the top. with the open loop part thats probably way to much.
I wont ask you what injectors to use etc because i know its been covered and i dont want a newbee arse rippin LOL.
Posted 14 July 2002 - 09:16 AM
I also pulled my plugs out and they were also all BLACK full of Carbon.The tip was brown though.
This indication is CLEARLY showing EXTREMELY RICH because my car has not been tuned yet and this would explain the misfire problems we are both having.
I just recieved my NEW O2 housing from ALipine on Friday so i will be installing it in excatly 2-3 weeks.They were KIND enough to send me a NEW O2 housing BORED OUT with a bigger Flapper.I believe he machined anywhere between 2-5mm to eliminate my Boost creep and hopefully this will rectify the problem.
Once everything is installed i will Dyno my car with the S-AFC and 440cc injectors i have and will post the results for you guys.
Im running SUPER RICH Now because i installed my new Walboro pump and currently im at 32psi at idle and at WOT it hits 90PSI which is so HIGH.
I believe the reason for this is because i dont have a stock regulator in and all i have is the RRFPR from Alpine and tahts whats causing the extreme high pressure.Im installing an AEM 1:1 ratio FPR to eliminate the bouncing of the Fuel pressure at idle.
Anyways i will post results in about 3 weeks exactly and they you guys know
Posted 14 July 2002 - 09:40 AM
and as Cheuk commonly recommends, *tuned with a wide band 02 sensor*
Posted 14 July 2002 - 01:12 PM
2UNIQ, I also believe you are running too rich and the over rich condition is fouling your plugs.
What exactly are you running for fuel? RRFPR, larger injectors and S AFC?
2UNIQ... Get that thing TUNED!!!
Posted 15 July 2002 - 01:59 AM
in order to keep the cost of their kit low, alpine has you reuse the 4 stock injectors, and then uses 1 large 340cc injector as a *5th* injector BEFORE the TB.
This 5th injector, and the 4 regular injectors need to be tuned by proffesinals familar with the UniChip. Alpine has taken 4 tries at tuning my unichip with no luck. It's going to go to a *professional* tuning shop next. I'm also dumping the 5th injector and going with 4 550cc injectors. The *head spacer* is also being ditched in favor of 8.4:1 ratio pistions. This should solve the misfiring, and the rich condition. (he he...should. Cross your fingers).