sputter and overboost????

[LITLV6]

to make a long story as short as possible. i posted about "lean out pop" a few weeks ago and thought i had i figured out with my fuel pressure dropping at WOT that i would need a new pump. i installed a walbro and hotwire kit. at the time i was doing this i installed a hotchkis TVS suspension system, a set of bilsteins, all new steering links as well as the pump and harness. (i also have new 60lb mototrons and a new TT 5.6 chip to put in) i didnt want to add to the variables before making sure the lean pop was gone, so i havent installed them yet.

i went to drive the car and it wouldn't boost over about 14lbs. sputterin and just soundin kinda crappy. i figured maybe i messed up some vacuum lines and so i replaced them all! also fixed my PCV hose which was kinked. the car then boosted around 25lbs!! and STILL POPPING OUT

Ok, so at this point i figure the PCV kink maybe was messin with the car and the previous owner turned up boost because of the line bein kinked so i adj. the wastegate back till i boosted around 20lbs. (it was around 19 before, and its still popping out. i also replaced the MAF with a stock style just to see if the K&N oil fouled it up. (just an idea, dont know if this happens to anyone or not). now i'm at a loss...... could it be coil?? plugs??? or should i proceed with the new injectors and chip???? i run about 4.5 gallons of 110 as a mix with the rest of the tank 93. anyone with ideas?

 

[Beamer]

Are you running a wideband along with your scanmaster? What O2 numbers are you getting? Are you leaning out or just popping?

I ask this as I had what I thought was lean popping. I would run moderate O2 numbers and then pop and show leaner numbers at the pop. I tried new pump, filter jacking the alky up and all, but did not cure the proplem. I ran compression and leak down checks and everything looked good. I finally bit the bullet and purchased a roller cam kit. When pulling my stick out, there were 2 noticable lobes rounded off.

Ever since putting the roller kit in, I have been runninig strong and I am not looking back. Just a thought. The cams today do not like the oils out there and our motor design does not help any either.

If you have wide band that is the way to tune. Also think about a powerlogger if you are serious enough into the game, which it sound like you are. The PL will also display your wideband info and save it for leanest display like your narrow band does now on the scanmaster. AND - you can log your data to a laptop for much better tuning ability.

Just my $.02 worth...

Mike

 

[TurboBuRick]

IMO sputtering is more of a ignition problem. Try unplugging the cam sensor while the car is running. Leave it unplugged and go for a ride.

Still sputtering?

 

[Beamer]

IMO sputtering is more of a ignition problem. Try unplugging the cam sensor while the car is running. Leave it unplugged and go for a ride.

Still sputtering?

I do agree about sputtering, but the popping is a question, as in what did the O2 numbers look like also.

Mike

 

[LITLV6]

IMO sputtering is more of a ignition problem. Try unplugging the cam sensor while the car is running. Leave it unplugged and go for a ride.

Still sputtering?

ok i'll try this. its tough for me to get to the car cause i keep it stored. i'll try to do this monday morning before work. thanks for the input... i hope its just ignition related. the coil is original i believe. i put a set of Taylor 10mm wires on it and i have never touched the cam or crank sensor but i did put a new set of plugs in it last year...


The funny thing is and BEAMER the reason i'm hopin your wrong about the idea of the cam lobes bein worn off is that it did this before...... stupid me i did several things at once tryin to chase it and fixed it and wasnt sure what really solved it. could it be just as stupid as a plug fouled?? maybe cause i run partial 110 octane?? can it sputter enough to cause the wastegate to close momentarily and then pick back up and momentarily overboost causing the pop out?? any relevance to that at all or am i just bein hopefull?? lol

TurboBuRick and Beamer thanks again for your input, its much appreciated.. and anyone else that has ideas or input thanks in advance

 

[LITLV6]

I do agree about sputtering, but the popping is a question, as in what did the O2 numbers look like also.

Mike

you ask about the O2 numbers... i'll also have to look at it, but doesnt the O2 go open loop at WOT????? or does it still have an input at WOT?

 

[Beamer]

you ask about the O2 numbers... i'll also have to look at it, but doesnt the O2 go open loop at WOT????? or does it still have an input at WOT?

Hey V6,

Why do you mix fuels?

Are you running boost levels for above 93 octane? Personal recommendation, tune your car for the street and 93 octane and work it from there. What chip are you running?

I believe the control is open at idle and closed at WOT. Maybe I have the terms backwards, but at WOT, the chip is looking at your narrowband for determining to add or remove fuel, and at idles, it is "open" at a determined moderately programed value.

Race fuel can damage some of the NB O2 sensors and cause some problems. That is most likely what your ECM is using to determine how much fuel you need at WOT especially.

I would suggest straight pump gas first off. Next, get a wide band O2 system, possibly a powerlogger to aid in tuning, and if you want higher boost and HP levels, get an Alky kit to compensate for boost adding.

 

[LITLV6]

Hey V6,

Why do you mix fuels?

Are you running boost levels for above 93 octane? Personal recommendation, tune your car for the street and 93 octane and work it from there. What chip are you running?

I believe the control is open at idle and closed at WOT. Maybe I have the terms backwards, but at WOT, the chip is looking at your narrowband for determining to add or remove fuel, and at idles, it is "open" at a determined moderately programed value.

Race fuel can damage some of the NB O2 sensors and cause some problems. That is most likely what your ECM is using to determine how much fuel you need at WOT especially.

I would suggest straight pump gas first off. Next, get a wide band O2 system, possibly a powerlogger to aid in tuning, and if you want higher boost and HP levels, get an Alky kit to compensate for boost adding.

the alky is gonna be an upgrade this spring hopefully. the chip is an older one from years ago... previous owner had it made... the program in the chip works better this way and i have gotten used to it. i have a drag stip 10 min. from where i live and they carry it.... i have new injectors and TT chip to go in the car, i was tryin to solve this problem before adding the extra variables. i do have a new Delco O2 in the car and MAF. did both yesterday with no change at all lol damn gremlins.....lol

 

[Beamer]

If you have the injectors and chip, I would recommend at least thinking about swapping. Here is why... I purchased my car a little over 2 years ago. It had a Reds chip in it and came with his race chip in the glove box. The car ran great when purchased and would rip the tires like crazy. After driving a month or so, I noticed the car had occasional problems going above 4500 RPM. It would come and go. I also noticed it would sputter and break up as well. The car would also have idle problems that was intermittant. I have a witness to all of this, being CME2FLY on the board. I ordered a TT chip for my combo as I was adding alky. I installed the alky and TT chip and my car was completely different. The idle was so much smoother, the acceleration was smoother, the breakup and RPM problems were gone.

I don't think it was the alky that did it for me, but the TT was the cure. Not knocking Reds chips in general, but his was not working good in my car. I lean to it being more "old" school and the TT tunability is so much of an advantage also.

I hope you find your problem quuickly and inexpensively...

Mike

 

[LITLV6]

If you have the injectors and chip, I would recommend at least thinking about swapping. Here is why... I purchased my car a little over 2 years ago. It had a Reds chip in it and came with his race chip in the glove box. The car ran great when purchased and would rip the tires like crazy. After driving a month or so, I noticed the car had occasional problems going above 4500 RPM. It would come and go. I also noticed it would sputter and break up as well. The car would also have idle problems that was intermittant. I have a witness to all of this, being CME2FLY on the board. I ordered a TT chip for my combo as I was adding alky. I installed the alky and TT chip and my car was completely different. The idle was so much smoother, the acceleration was smoother, the breakup and RPM problems were gone.

I don't think it was the alky that did it for me, but the TT was the cure. Not knocking Reds chips in general, but his was not working good in my car. I lean to it being more "old" school and the TT tunability is so much of an advantage also.

I hope you find your problem quuickly and inexpensively...

Mike

i'm gonna try to swap it all this week. i'm not sure of the make of my "old chip" either but mine has several....... i ordered an injection harness as mine has a lil tape on it here and there. may not be any significance but its one more thing i can rule out.

mine also doesnt run over 4500 very often, seems intermittant. and has a weird idle sometimes.

 

[Beamer]

i'm gonna try to swap it all this week. i'm not sure of the make of my "old chip" either but mine has several....... i ordered an injection harness as mine has a lil tape on it here and there. may not be any significance but its one more thing i can rule out.

mine also doesnt run over 4500 very often, seems intermittant. and has a weird idle sometimes.

Hmmmmmm

Interesting. Keep us posted how it goes. I hope it takes care of your issues.

Mike

 

[QUIP'6']

hmmmmm!!!