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Forum namePerformance/Engine
Topic subjectbad misfire, and hard starting 4g63t please help!
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=70178
70178, bad misfire, and hard starting 4g63t please help!
Posted by jasonlee, Mar-08-04 09:03 AM
ok, i have my swap done, but now i have some tuning issues...

the car is seriously hard to start if its sat for awhile (a day or half a day).... once you start it it starts pretty easily...

has a misfire but it happens often, and not steadily... also... about 3000 rpms the engine cuts out really bad... and sometimes drops 2 cylinders from firing and i can hardly keep it running... (only when driving though)

sometimes it smooths out and gets past 3k rpms... then at about 4500 or 5000 it does it again but worse....

possibly coil pack issues?? maybe waste gate on turbo not opening? i have no clue here people please help!!
70179, RE: bad misfire, and hard starting 4g63t please help!
Posted by REV_GSlow, Mar-08-04 09:26 AM
when i had my 4g63 it would do the same thing, but the wristpins were installed backwards and my car would detonate/miss/cutoff above 3500rpms. Are you getting any CEL's? It is possible that the coil was damaged prior to installation, i cant remember what happened to the car you removed it from. You should be able to find a cheap replacement and test it out. How about cam and crank position sensors..they control timing/firing of injectors and such. These are just a few things to check and im sure others will add to it..best of luck.

EDIT: i didnt think about fuel cut, might have to ask someone else about that though. Check all connection concerning your fuel..and i know this is a dumb question, but are you using the 4g63 fuel filter and pump?
70193, RE: bad misfire, and hard starting 4g63t please help!
Posted by jasonlee, Mar-08-04 03:23 PM
i am using everything from the eclipse awd.... even the fuel lines with a few inches added to them. additionally, i am using a wahlbro high flow fuel pump, and 510cc injectors... so i dont think there is much worry of fuel cut.... i could be wrong though.

could it be i am not providing enough boost pressure, and therefore flooding the engnine at higher rpms?

maybe bad spark plugs?? it had ngkbp7es or what ever... in it...


70215, RE: bad misfire, and hard starting 4g63t please help!
Posted by REV_GSlow, Mar-09-04 02:39 AM
ive always heard that running a step colder plugs works wonders for a turbo motor, it helps with detonation. I think the code for them is 11es or so. Can you hear your turbo spooling while all of this is happening? Also, what size turbo are you running and if its the t25..why are you running bigger injectors? Do you have a SAFC to tune your fuel/air? Im a begginer with all of this too but i do know a little and i'll help as much as i can. X Hyper TSi X on aim if you need to ask a question.

Did you prep the turbo before installation? If the gsx had been sitting for a while its a possibility that the turbo seized on you, i always pour a little oil into the turbo inlet and move the turbine around a bit to make sure it isnt stuck. Theres alot of gunk in the stock turbos and hardening up isnt weird.

When the car does this, stop and use a multi meter and check the voltage of the coil pack. The haynes/chilton should have the correct voltage for you.

Also check for HUGE vaccum leaks. Its quite possible that something isnt tightened down and theres a large amount of air entering the motor without being detected by the MAS.

Check it out and get back to me, im sure i can add a little more.
70217, RE: bad misfire, and hard starting 4g63t please help!
Posted by JWoodley, Mar-09-04 02:51 AM
Gasket leaks or unhooked vacuum lines are not your friends, but they are alot easier to fix than most other problems.
71063, RE: bad misfire, and hard starting 4g63t please help!
Posted by jasonlee, Mar-19-04 08:04 PM
well, it seems that my mass air flow was from the wrong car.... and my o2 sensor was bad....

and the turbo is a big 16g... and i made sure it was working

i think i have problems worked out... just waitng on a maf translator now, and a new o2 sensor..

we will see...lol.. additionally, i dont have a safc yet.. but i will be getting that soon.. i know i need it now for sure!

j


avenger gsx... come get some

71064, RE: bad misfire, and hard starting 4g63t please help!
Posted by jasonlee, Mar-19-04 08:07 PM
anybody selling a maf translator?? lol
avenger gsx... come get some