missfiring or boost cut?

[Guest]

howdy,

just recently i added a boost controller to my galant which is practically stock. nd ran it on 12-13psi boost. it ran absolutely fine for a few days nd then i started gettin bit hard cuts like i hit a wall.

at first i thought it was a boost cut but now am running 10-11psi boost nd still cutting, some times not as bad. what could it be? ive changed spark plugs bout 6 months ago nd now it feels like the same problem again. but if i lower my boost it improves but still slightly feel the cuts.

just wondering what it could be. plugs? boostcut? fuel pump?

cheerzz

 

[pu-11-me]

howdy,

just recently i added a boost controller to my galant which is practically stock. nd ran it on 12-13psi boost. it ran absolutely fine for a few days nd then i started gettin bit hard cuts like i hit a wall.

at first i thought it was a boost cut but now am running 10-11psi boost nd still cutting, some times not as bad. what could it be? ive changed spark plugs bout 6 months ago nd now it feels like the same problem again. but if i lower my boost it improves but still slightly feel the cuts.

just wondering what it could be. plugs? boostcut? fuel pump?

cheerzz

Check the connection where the controller is getting the plenum pressure from. If this is leaking it'll think there is less boost making the car make more boost when it shouldn't be. I bet your gauge is wired off that same line too saying its only lower PSI than its making

Good Luck

 

[Guest]

will give that shot, cheerz

placed the boost controller same place how i read on this thread.

http://ozvr4.com/forums/showthread.php?t=908&highlight=controller

 

[dimi_108]

Sounds like your'e hitting boost cut.
Lower the boost settings to 10psi and give it a nice hard drive for 10 minutes. See how you go.

If you're still getting the "violent" misfire (especially under load in the lower RPM's) you'll need to do your plugs and leads.

 

[bradc]

Possibly coils, plug gap if it is minor. If it really is like hitting a wall then you are hitting boost cut

 

[Guest]

yeh sounds like its a boost cut. on low boost doesnt happen but any thing higher than 10 cuts pretty hard. is this normal? tends to be worse when the engine is colder aswell?

 

[pu-11-me]

yeh sounds like its a boost cut. on low boost doesnt happen but any thing higher than 10 cuts pretty hard. is this normal? tends to be worse when the engine is colder aswell?

Boost isn't just the PSI it displays. Colder air is denser. Denser air = more air at the equivalent pressure..... Hope that makes sense

So its definately boost cut. If you are getting more air at 10PSI than everyone else is at 15 you are doing well!

 

[Guest]

Boost isn't just the PSI it displays. Colder air is denser. Denser air = more air at the equivalent pressure..... Hope that makes sense

So its definately boost cut. If you are getting more air at 10PSI than everyone else is at 15 you are doing well!

sorta get ya lol. so im gettin to much air than fuel by ratio? does this mean il have to upgrade my fuel pump nd injectors to run higher boost. when i first ran it thou it had no problem running 13psi few a few days lol.

cheerrz

 

[pu-11-me]

sorta get ya lol. so im gettin to much air than fuel by ratio? does this mean il have to upgrade my fuel pump nd injectors to run higher boost. when i first ran it thou it had no problem running 13psi few a few days lol.

cheerrz

Its trying to put in more fuel to match the amount of air but can't, thats the one .... I wouldn't go upgrading anything until you find out why its cutting. Mine didn't at 13PSI in minus 10 so i don't see why yours would be unless there is an install problem with the controller..... Thats where i would start anyways. Just double check everything and reconnect the hoses and look for leaks

 

[Guest]

kool kool. well i havnt check the plugs yet, bit it will sooon lol cos theyre a pain in the ass to get to haha. but its fine on 11psi when its warm or the weathers warm, but if the car or weathers colder it cuts at 11 everytime, alot harder in 2nd gear say, than 4th or 5th. sound normal for a boost cut?? or something else.

 

[Kenneth]

Do you have a non standard intake?
I have known of a few cases where the incorrect MAF readings caused premature fuel cut.

 

[Guest]

k&n highflow pod. these r compatable with the car thou i belive. one of the only ones that dont interfere with the airflow meter.

 

[TTVR4]

change your plugs and leads, this will fix the prob.
evryone i have spoken to who adds boost starts get a miss. from a weak spark. change these and all fixed...

 

[Guest]

pod filters are shit, no matter what anyone says

i'd put money on if you put the stock intake back on,
reset the ecu,
you'd be able to boost at least 14psi without issue (unless its really cold)


miss fire and boost cut are completely different,
miss fire is gentle compared to boost cut,
boost cut is violent like hitting a brick wall

 

[Guest]

Do you have a non standard intake?
I have known of a few cases where the incorrect MAF readings caused premature fuel cut.

yeh sounds like could be the problem. have asked around nd hada few mates with same problem after adding few mods to their cars, just needs a tune to correct this i hope, cheers for ya help

 

[Guest]

ANSWER = cheap ebay hosing lol

i started noticing there was no vacuum on my boost guage nd it started up at 0, so i checked my hosing nd was all melted that i got of ebay that came with my gauge haha. boost cut gone

cheers again for evry1s help.

 

[pu-11-me]

ANSWER = cheap ebay hosing lol

i started noticing there was no vacuum on my boost guage nd it started up at 0, so i checked my hosing nd was all melted that i got of ebay that came with my gauge haha. boost cut gone

cheers again for evry1s help.

Woohoo.... I knew i was right with this one!

Good to hear its fixed mate