sputtering under boost, plugs?

[Bastard1g]

I just fixed all the boost leaks and fuel leaks last night, I boost leak tested it before I put everything back together and it checked out ok. Before I fixed my fuel leak at my orings and fixed my boost leaks around the couplers, It ran better. It ran like crap but it did not sputter. Now it idles ok but when you rev the motor it sputters. Also under boost it sputters but the engine runs fine in the vaccum range. also when i try to boost it, I see 13:1'ish. also. I have the stock spark plugs with 2 electrodes. I pulled em and they were a lil black with white tips. anyone have any ideas?

 

[98eclipsespyder]

hey i had those same plugs, i just changed mine, i used to be fuel cutting, when i stepped on the gas all the way, it bogged, so i got my new spark plugs, NGK BRP7e or something like that, i got one step colder, and now everythings runs awesome no bogging or fuel cutting, it runs great, try buying them, they are only like 11 dollars for all 4

 

[Bastard1g]

I wish mine would bog, all mine does is sound like a machine gun.

 

[beat90tsi]

try raising fuel pressure, i had the same symptoms and that was my problem

 

[rob_rousseau]

hey i had those same plugs, i just changed mine, i used to be fuel cutting, when i stepped on the gas all the way, it bogged, so i got my new spark plugs, NGK BRP7e or something like that, i got one step colder, and now everythings runs awesome no bogging or fuel cutting, it runs great, try buying them, they are only like 11 dollars for all 4

Plugs causing fuel cut?

 

[Bastard1g]

actually, I am running 42 psi instead of 43 but I will fix that on my lunch break. I dont think that 1psi of fuel preasure will make a difference though. I will try that though.

 

[Spyke169]

i had the same "Machine gun" noise problem under boost. I regapped my plugs and solved the problem. you may as well just replace them with some BPR7ES plugs, that should fix the problem, but regapping them was all i had to do. The stock plugs with the 2 prongs are pointless IMO, they will only fire from one side anyways

 

[Bastard1g]

Yea, I agree. I will try to replace my spark plugs on my lunch break and see what happens.



this is my mod list by the way.


20g vrs 3" turboback exhaust cone filter dejontool race fmic kit dejontool intake pipe act2600 ss clutchline Aem wideband gauge 780cc injectors 95 eprom ecu with keydiver chip aeromotive afpr, earls fuel filter with -6an fuel lines re-wired 255 hp fuel pump 1g bov with dejon tool seal kit mod prothane motor mount inserts 6bolt swap, Rebuilt stock internals, Arp fasteners,Balance shaft eliminator kit coil overs/ ford probe gt wheels 225/50/16 kumho's

 

[i1nk83]

is this a 2g 6bolt swap car? if so it sounds like you are getting the famed random misfire. local guru around here found that if you place a variable resistor inline with the mas you can eliminate this. not sure exactly how to do it tho, might wanna search for it

 

[Bastard1g]

Well, I just put new plugs in there (bpr7es) and it still sputters under boost. Its messed up cause it idles good and cruises good but once you hit 1 psi, it starts to sputter. I will do some searching on the random misfire issue.

 

[Bastard1g]

ok, I have been searching and found that the random misfire code doesnt fit my description of symptoms. First thing I did was disconnect the tps, and it still drove the same. Also, it doesnt matter what rpm range, once I hit boost, it sputters. all I can do is try to play with it more. Any suggestions?

 

[DSM Loki]

i had the same problem, but it occured a lil higher in boost, mine was the spark plugs wires, at the coil pack the electrode thing detatched so it wasnt firing right under boost but rest of time was fine. probably not the problem in your case but i figured i'd throw it out there. also make sure the coil pack is good and that you have a good connection at the coil pack transistor. actually, just make sure you have good connection at everything in the ignition system. check all primary and secondary connections. hope you find out its something stupid simple, rather than stupid complicated.
also, are you positive that you used the right coil pack? i know its a stupid question but just something i thought of

 

[Bastard1g]

Yea, its weird but it ran better and faster with a boost leak and fuel leak. I fixed both of those at the injectors and it runs like ass on boost now. it idles better but once you hit 1 psi, it spudders. I replaced the plugs with bpr7es and nothing. So I am wondering why fixing a boost leak and fuel leak can make my car not like boost? My tps is plugged in, my injecotors are plugged in, so I am clueless right now.

 

[Boiler2]

I had this issue with sputtering under boost in all gears. I ended up changing my spark plug wires and the issue was solved. Just my $0.02.

 

[Bastard1g]

I had this issue with sputtering under boost in all gears. I ended up changing my spark plug wires and the issue was solved. Just my $0.02.

I would consider that but I have some msd 8.5mm wires that were almost brand new when I put them on. Also, when the boost leaked and fuel leaked, it was able to make 20 psi with no sputtering. It felt slow but it didnt buck like it does now.

 

[Bastard1g]

also, I just saw this post and this guy has a 97 car and he said that he found the brown jumper plug for setting the timing. Is there one for our cars? keep in mind I have a 95 ecu.


http://www.dsmtuners.com/forums/showthread.php?t=78851&highlight=misfire+boost

 

[Green93TalonTSi]

Seeing as you have a 95 ECU, make sure you hav your firing order correct. Also check your timing. I had a similar problem to this . I had taken my motor from my 1g and dropped into my 2g and I had the timing to far advanced. After I fixed the timing i could boost over 10psi with no problems.

95-96 have the grounding plug in the engine bay, 97-99 dont. In order ground out, jsut plug in an OBD2 connector in the diagnosic port and it will ground and show baste timing.

 

[Bastard1g]

Well, I had it set for 5 degrees btdc, then I set it for 7. When I set it for 7, it was easier to drive only because it would stay in the vaccum range longer. I am going to set it back to 5 and then start all over again. There has to be something in the ecu telling either the injectors to shut off or disable spark to only have this condition on positive manifold preasure. I could drive this car all day long in the vaccum range just fine. Even with the 20g, it is still hard to keep it from boosting though.

 

[Green93TalonTSi]

I have a 50 Trim, and i have my timing set at 5BTDC and its fine. I had mine at 7 as well and the car ran like absolute shit, pretty much the way yours is. I guess 2g's dont like to much timing advance. But I would put it back to 5 and check your firing order and then go for a test drive and see what happens.

 

[Bastard1g]

I wish it was my firing order. It made boost when it had a boost leak. Its when I fixed the boost leak, when the sputtering problem happened. I got on it once and it 20 psi with no knock (according to my knock gauge from the keydiver chip) it ran like crap but it didnt sputter. I will recreate a boost leak and see if the problem goes away. I know one thing, when I try to boost at wot, I am hitting 13:1 afr.

 

[Bastard1g]

I finally got new plug wires. still sputters. I will run another boost leak on it tonight. I will keep you all posted. When I find out whats wrong with it, I will post my results so someone else can fix thier problems.

 

[Green93TalonTSi]

Can you build any boost at all ? I still think its your timing.

 

[slowpokin699]

I was thinking the timing as well. I saw about 10 psi building but it would sputter so bad you wouldn't feel the pull. it's almost as if there is a vacume leak and it kinda sounds like one too but we found nothing. I looked at it briefly a minitue ago. He did set the timing but there is no jumper wire for the 98's to put it into defaut mode, he had to set it without the jumper wire.

 

[Green93TalonTSi]

Look at my previous post, and you'll see how to put your timing to default mode.

IF you have a logger, DSMLink, or an OBD2 scan tool, plug it into the diagnostic port under your dash. By doing so, it lets you adjust your timing, and adjsut from default mode. Put it back to 5 degrees BTDC . you are having the same exact problem I had before i fixed my timing. Was able to boost 10psi, but anything after that it would fall on its face and stumble.

 

[slowpokin699]

Looks like he'll have to wait untill he can use a co-workers scan tool on monday since we dont have a logger or dsm link for his car. Thanks for the insight.