i did a search but found nothing.

well i have a sohc vtec turbo and between 3k and 4k rpm and in boost my car sputters. i have no idea why, it only sputters during these rpms. but when i am not in boost it does not sputter. i changed plugs, wires, shot timing, and there are no vacuum leaks either. any idea what it could be

 

Possibly too much fuel??? Is it only at WOT or does it sputter while the gas is only partially depressed???

What do you have for fuel control?

 

what do you have your plugs gapped to?

 

i just have a 12:1 fmu and inline fuel pump for my fuel. it sputters alot at partial throttle and alittle at wot. and my plugs are at .32 and i have msd ignition. the thing is it only sputtered after i put in the inline pump. before i had the pump i was driving a bit and i did not sputter only after i put it on.

 

sometimes my car acts like a bitch that way.. when cruising along at a steady pace, throttle just left at one spot it starts to speedup and slowdown a tiny tiny bit.. almost like it's sputtering.... everythign seems fine when it's doing it... but i feel almost positive that it's cause it's getting a lot of fuel..

doesnt do it all the time either...

cant say it does it in boost though.... car just wails like a banshee in boost...

 

I was having the same problem. I was running a msd inline and a paxton 12:1 fmu.. At higher rpms it would spit and spudder. so I on hooked teh msd pump and it works fine now.. But I am having other problems like when it starts to boost my fuel presure goes down to almost 20 psi?? WTF is with that .. ha ha . So I think it was staving the lines. You should try to on hook the inline once and see if that works.. Hope I helped a little . If anyone knows whats wrong with mine please help. I pulled out my intank tonight I am going to try to run just teh inline I think and take out the intank???

 

Gap your plugs down to .030....

If still sputtering, turn down the fuel.. Are you blowing smoke under throttle??

And remember... tuning is fun..

-Jaosn

 

with the msd, you can actually make the gap bigger. you sure you got your inline installed correctly?


[Modified by dlplayboy, 10:50 PM 6/25/2002]

 

i have the same probelm and i'm running

b20
rev hard
440 cc injectors
b&m in-tank pump
fields afc..
according to my fields its saying i'm running lean.. when I richen it up its sputters even worse..

 

It's always going to be one of these two... too much spark retard or too much fuel. Most of the time it's too much fuel. Enjoy. Oh yeah, don't belive any .02 air/fuel guage that reads off of your stock o2 sensor or any other o2 sensor that's not wideband. It's worthless. I thought I was running rich when in fact I was running lean before I tuned with a wideband. It wasn't lean by much 0.5-1.0, but it was still incorrectly displayed on the guage.

Almost forgot... screw that inline BS pump. Get yourself a Walbro GSS342 pump and replace your stock one with it.

 

hmm actually we retared the timing it a bit.. wat should it be at??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TORQUE MONSTER &raquo;</TD></TR><TR><TD CLASS="quote">hmm actually we retared the timing it a bit.. wat should it be at??</TD></TR></TABLE>

That depends on a lot of factors. What is it at now? Are you running enough fuel? Is it intercooled? How hot is it where you live right now? Remember that too much spark advance combined with not enough fuel will be worse then just not enough fuel (if both units remain constant in the example.) Usually on a good intercooled setup it's .25 to .5 of a degree per pound of boost if fueling is proper. That of course is an estimate, but it's a good place to start if tuning with proper tools.

 

i dont know where its set at.. all i know is the red line supposed to be right on the timing belt cover indicator.. and i retared it a bit..

yeah its intercooled.. the temp here is like 70-75

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TORQUE MONSTER &raquo;</TD></TR><TR><TD CLASS="quote">i dont know where its set at.. all i know is the red line supposed to be right on the timing belt cover indicator.. and i retared it a bit..

yeah its intercooled.. the temp here is like 70-75 </TD></TR></TABLE>

Please don't take this the wrong way, but that's WAY scarry dude... I'm really starting to understand now how there could be so many blown engines when it comes to FI. You've spent all that money on a nice car/engine/turbo kit and you're not going to use proper tools to measure something as simple as spark timing.

 

err this is why i'm asking people on this board questions.. so if u dont mind will you enlightening me on what tools i need..?? I have a timing gun.. but it doest tell the precise degrees..

thanks

 

You don't have the right kind of timing gun then. A timing gun is very important and a cheap one is just that... cheap. Find yourself a nice digital one... it doesn't have to be an expensive SnapOn one, but I've seen others for like 100 bucks or so. With a digital one you can see exactly what you're at. None of this eyeballing it thing. I'm not trying to pis* you off dude... I'm just saying. Imagine how it would suck for you if your doctor put in a pacemaker on your heart but set the electro-discharges incorrectly. It's the same thing for your engine...

Here's one..

http://store.summitracing.com/...D3568

Peace