Stutter at 13-14 psi

[Cool Mr Steve]

Ok, my car stutters at around 13-14 psi. As soon as my car reaches that boost level in any gear, it stutters like crazy and starts to sound like it is backfiring a little. I do not have any boost leaks, and my spark plugs are good. When I take out my plugs, though, after about 10-15 miles my plugs are fouled. My FPR runs at 40 psi with the vacuum line off, by the way. Also, I don't know if it is a related issue, but with my vacuum gauge connected to the intake manifold the reading is 14 in-hg. Does it sound like a bad ignition coil?

 

[talonawd94tsi]

try gapping your plugs between .025 to .030

 

[Attack Eagle]

o.028

glad you got the cas problem fixed (I assume?).

sounds like you havfe a boost leak at that point and are getting WAY more air (and thus fuel) thru the MAS than what the engine is actually seeing...


Mine wound up being the stock "wraparound" coupler for the UIP to upper I/C...

 

[madaba]

Have you actually pressurized the intake system to about 20lbs to check for boost leaks?
Is this something that just started happening one day or was after a mod or doing something?

 

[captd108]

in case you havent done this yet i would get new plugs and gap them at .028 also new wires might be helpful as well. Base fuel pressure on a 2g is supposed to be 42.5 psi. If i were you i'd do an actual boost leak test and make sure you are not losing air anywhere. I had a similiar problem when i first had my car and it was because of a couple of small leaks which caused my plugs to go bad and therefore cause the stutter youre describing which happens probably because your ecu is dumping in more fuel than what its supposed to like. Just check for leaks and get new plugs and if you want wires, gapped at .028

 

[Cool Mr Steve]

What type of air compressor do you guys suggest for the boost leak test??? I have the small car portable air compressor that SAYS it can reach high PSI's, but it only seems to be able to get up to about 3-4 psi... Is this just because of a boost leak? Or do I just need a better compressor? BTW... Thanks a lot Attack Eagle for your help with my other car issue... Yes I was able to get my CAS back on and running, but I still have a few issues... Oh yeah, and my plugs have always been gapped to .028.

 

[madaba]

I've used a 5-10 tank before that you have fill up that are meant to inflate tires and are usually pretty cheap at wal-mart. While most don't come with a regulator on it, i put one on it and filled up to 100lbs then dialed it down to 20lbs so i didn't have to keep filling it up all the time, and worked good for me until i got a real compressor.

 

[Cool Mr Steve]

Is that to say that my crappy little portable car compressor won't do the job?