98Ztwentyeight

iTrader: (2)

While under full boost or 5psi right when it gets to 5 psi my engine starts

coughin is the best way I can explain it.

it wasnt everyday but ounce in a while it would start to hesitate

and pop a little. while at idle or under boost but not mid throttle.

but now its constant.

I thought it was a bad tank of gas when it happened last month.

so switched gas stations and had no problems for a bit and now

its doing it again. i just filled up too....

its also pulls timing like crazy. normally im at 16- 15 deg when under full

boost and when this happens it drops down to 7 or 6 deg on my scan

guage should i start with a fuel filter? or try and put a fuel guage onit

and tape it to the windsheild and see if im losing pressure at boost

maybe this gas station has bad gas too now.....

where would you guys start??

if i half throttle it my car runs as smooth as glass but when i nail it ...it

coughs almost like a misfire but its not backfiring at all just little pops in

succession like its coughin...

my car was tuned on 91 octane . and thats what i have been running

any help would be appreciated..

my mods are listed below 42lb injectors walbro pump...

thanks
matt

CODE4LS1

iTrader: (4)

sounds to me like you may be running a little lean....may want to upgrade the injectors to at least 30# if running stock fuel pump

98Ztwentyeight

iTrader: (2)

my mods are listed below im usin 42lb injectors and walbro pump

everything is about 4 months old now.

CODE4LS1

iTrader: (4)

sorry i didnt even bother looking.....my bad.....then I would have to say it may be a fuel filter. Sounds to me that your timing issue is the most probable culprit, especially under 5lbs boost.

98Ztwentyeight

iTrader: (2)

anyone prefer one fuel filter to another??

any one brand to stay away from?

i think im gonna try that and see what happens..

any more suggestions? my fuel filter is about 5 month old too..

DarkblueTA

change the fuel filter and put in some dry gas. Sounds like you may have water in the tank? Might just ask Rob or Jason to look at it quick. I know their busy but maybe they might have another solution....

OUTLAWZ RACING

iTrader: (9)

Mine use to do the same thing strap it to the dyno lost 150 hp it ran pig rich right off the scale reloaded the tune it ran fine for 4 days full boost 8psi and then it did it again the culprit was my mass air meter and my map sensor funny thing was on the dyno it was fine reading where good my tuner took it for a test ride with me in it and it was good but when it started again i had my scan tool and my map sensor was stuck at 1.0 and my mass air meeter was at 0.00 while cruzing then i boosted on the low setting it sputterd and then took off readings where still the same odd thing is i change them both and the car ran fine not sure what caused it but that was my deal when my car cough.

Blackbird

maf get wet?

98Ztwentyeight

iTrader: (2)

thanks for all the suggestions

i guess ill start with a fuel filter and go from there

according to my scan guage my map sensor is definatley reading

but i guess it could be my mas airflow sensor on its way out

or just crappy gas again... we'll see

Zombie

iTrader: (2)

Check your plugs as well. Your symptoms sound similar to spark issues. I've found gapping to .028 works the best on ngk tr6's. I had a cracked plug and it acted very strange, would run ok until I hit 3 psi then it sounded like the car was falling apart. Would also miss at times at idle. If you have scanning software pull up your missfire counts and see if you can locate the culprit cyl. It should be the one with the most miss counts. Don't be suprised to see two with high counts with one slightly lower, it's probably just a carry over since it's the next one in firing order.

Devil's Due

Check your MAF to make sure oil isn't blowing by the turbo seals and covering it.

98Ztwentyeight

iTrader: (2)

DAMMIT ITS NOT DOING IT AGAIN!!

this is driving me crazy

i went out at lunch and its fines now drove it for 20 minutes

not a pop out of it..its like 30 degress warmer now though......

i dont remember what i gapped my plugs at but i did use ngk tr6's

i do have a little pop at idle ... cracked spark plug could be the

culprit i had a hell of time trying to get the plugs in with my big

hands in the way and i may have knocked one and put a harline

crack init. well so far this weekend im doing plugs and the fuel filter.

I dont have a data logging scanner /program and it looks like it

would be beneficial to own that.

im using taylor thundervolt wires.

they are really thick wires almost redicoulous lookin.

I allways used taylor wires on my muscle cars I have owned over

the years so thats why I went with those . i hope they arent the

culprit

tmister

iTrader: (1)

DB TA, are you the person that has the 427 TA and STS that Rob at Strictly installed for you.I was at Strictly having Rob do some work on my SS when you picked up the car and I was wondering how the car was performing.Have you had it tuned yet and found out what kind of RWHP numbers it is putting out.I am thinking of putting a 427 in my car in the future.I wanted to find out from you how the drivability of the car is on the street as far as NVH and how docile it is with the 427 and the STS combined.Have you had any blow by problems yet with the STS.Do you have all the accessories still in the car such as a/c etc. or have you taken all the accessories out of the car.I asked Rob the other day if he had spoken to you about how the car was runiing and he said he hadn't talked to you.Let me know what you think of your 427/STS setup.Thanks tmister@***.net

TaTommyWS6

Don't guess.

Buy a Wideband setup and be done with it!

(I would guess you are running way rich, but guessing is BAD when it comes to FI)

Tommy

98Ztwentyeight

iTrader: (2)

It turned out to be the ends of the ngk plugs "the screw-on tips"

were backing themselves off even though i tightened them!

i guess i should of cranked on them harder

now its all back to normal. Thanks zombie for the gap sizing

info.. my car is runing better with the .028 gap setting!!!

i have zero hestitation under boost now!

Zombie

iTrader: (2)

Glad to hear it's working again. Turbo cars can be SOOOOOoooo much fun to troubleshoot Usually it's something simple.