car doesn't pull like it suposed to

[LTUDSM]

today something happened to my dsm,i woke up in the morrning warmed up my car and went to the job,and i noticed that the car doesnt pull like it suposed to,the whole power juts disapered,(funny thing happened on my way home some kid with civic where tailgating me and when he got to the side he pressed the gas and ran away from me i even couldnt catch him () the first thing i thought its a boost leak,but when i got home i did a boost leak test ,i ran 25 psi but i couldnt find any leaks, time to time im getting cel on,so could it be o2 Sensor???? cause i dunno what else could gave the car that kind of weaknes
anyone had same prob wit their dsm's?????

 

[Spookcorleone]

I know one time I lost all pull on my DSM, acked like a 1990 DODGE NEON... come to find out the pin that holds the actuator arm on broke completely off from old age, and the arm itself fell off - making sure the car wouldn't push any boost at all.... you seeing any boost at all while WOT? (have a boost gauge?) car spoolin' at all?

 

[blackbyrd]

Read out your CEL, you can do it with a voltimeter, or make a buzzer/light.
http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.html

 

[VanIsleDSM]

same thing happened to me one time, wastegate actuator arm fell off.. check for that.

 

[LTUDSM]

well actuator arm is on,im building boost (13) psi but its not going like it used to go,plugs and wires are good,but my vac is low, before it was between 15-17 and now is between 19 and 21

 

[LTUDSM]

i checked my CEL and i came up that i need a new Oxygen sensor,but does the o2 sensor could cause that prob??? i mean the o2 sensor couldn't cause of loosing a power m i right???

 

[blackbyrd]

Possibly, it runs in an open loop mode when It goes bad.

 

[LTUDSM]

Possibly, it runs in an open loop mode when It goes bad.

what do you mean by saying this? i didn't get you

 

[blackbyrd]

A gasoline engine burns gasoline in the presence of oxygen . It turns out that there is a particular ratio of air and gasoline that is "perfect," and that ratio is 14.7:1 (different fuels have different perfect ratios -- the ratio depends on the amount of hydrogen and carbon found in a given amount of fuel). If there is less air than this perfect ratio, then there will be fuel left over after combustion. This is called a rich mixture. Rich mixtures are bad because the unburned fuel creates pollution. If there is more air than this perfect ratio, then there is excess oxygen. This is called a lean mixture. A lean mixture tends to produce more nitrogen-oxide pollutants, and, in some cases, it can cause poor performance and even engine damage.

The oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage. The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly.

The reason why the engine needs the oxygen sensor is because the amount of oxygen that the engine can pull in depends on all sorts of things, such as the altitude, the temperature of the air, the temperature of the engine, the barometric pressure, the load on the engine, etc.

When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to.

 

[LTUDSM]

A gasoline engine burns gasoline in the presence of oxygen . It turns out that there is a particular ratio of air and gasoline that is "perfect," and that ratio is 14.7:1 (different fuels have different perfect ratios -- the ratio depends on the amount of hydrogen and carbon found in a given amount of fuel). If there is less air than this perfect ratio, then there will be fuel left over after combustion. This is called a rich mixture. Rich mixtures are bad because the unburned fuel creates pollution. If there is more air than this perfect ratio, then there is excess oxygen. This is called a lean mixture. A lean mixture tends to produce more nitrogen-oxide pollutants, and, in some cases, it can cause poor performance and even engine damage.

The oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage. The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly.

The reason why the engine needs the oxygen sensor is because the amount of oxygen that the engine can pull in depends on all sorts of things, such as the altitude, the temperature of the air, the temperature of the engine, the barometric pressure, the load on the engine, etc.

When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to.

Thanks alot blackbyrd that helpped for me alot i changed new o2 sensor and the car runs muuuuch better then it ran before,and also i find out that my egr's valve's blocking plate got a lil hole in it so ill try to fix it today and see the results thanks again guys for your opinions

 

[blackbyrd]

Glad to hear you got her running!

 

[LTUDSM]

well i was happy just a week driving normal with brand new o2 sensor,but now the problem came back again??? what else there could be wrong???? could any sensors take down whole the power??? what if i redo who;e wac lines??? would it help???i just got my true 3" turboback exhaust,it pools much better but still no power,plus my boost is changing boost it self, i mean like while im going from second gear to the midle of 3rd it shows me 13 thats what i set it up,but when im at WOT it goes whole the way to 18,so thats the problems that i have

 

[92awddsm]

Possibly, it runs in an open loop mode when It goes bad.

Actually, the o2 sensor is only use during closed loop. Once you go to wot, the ecu goes to open loop and a/f ratio is now only dependent on airflow and engine load (airflow / rev). The o2 will never be monitored in open loop. The ecu only notices the o2 sensor in closed loop operation.

well i was happy just a week driving normal with brand new o2 sensor,but now the problem came back again??? what else there could be wrong???? could any sensors take down whole the power??? what if i redo who;e wac lines??? would it help???i just got my true 3" turboback exhaust,it pools much better but still no power,plus my boost is changing boost it self, i mean like while im going from second gear to the midle of 3rd it shows me 13 thats what i set it up,but when im at WOT it goes whole the way to 18,so thats the problems that i have

The excess boost is from creep caused by the 3" exhaust. Pull the turbine housing and port it to eliminate boost creep.

Now that you are experiencing boost creep, the loss of power that you feel is caused from timing being pulled due to knock. Fix the creep problem, get rid of knock, and then the power will be back.

 

[LTUDSM]

well i had the problem before i did my exhaust,cause i thought the cat was clogged but no when i did exhaust(no cat) i have same broblem,well the car spool up faster but still no power,what i think about boost cereep it would be better getting external wastegate setup,then porting turbo housing m i right??

 

[blackbyrd]

Actually, the o2 sensor is only use during closed loop. Once you go to wot, the ecu goes to open loop and a/f ratio is now only dependent on airflow and engine load (airflow / rev). The o2 will never be monitored in open loop. The ecu only notices the o2 sensor in closed loop operation.

Oh yeah yeah, my wording was off. You know what I meant. What about open circuit? The ecu is not using the 02 sensor if it goes bad. However you want to word it. I think the wiki post above describes it well^

92awddsm is probably right about it being timing/knock issue now. Do you have a pocketlogger, or a pda that you could use(you have to make a cable and download the software)?
Are you still throwing a CEL? Does you boost go up to 18 under wot, then slowly fall back down to 13, or does it stay at 18? What kind of turbo are you running?
Here's a good link on porting it: http://www.dsmtuners.com/forums/showthread.php?t=186525

 

[LTUDSM]

Oh yeah yeah, my wording was off. You know what I meant. What about open circuit? The ecu is not using the 02 sensor if it goes bad. However you want to word it. I think the wiki post above describes it well^

92awddsm is probably right about it being timing/knock issue now. Do you have a pocketlogger, or a pda that you could use(you have to make a cable and download the software)?
Are you still throwing a CEL? Does you boost go up to 18 under wot, then slowly fall back down to 13, or does it stay at 18? What kind of turbo are you running?
Here's a good link on porting it: http://www.dsmtuners.com/forums/showthread.php?t=186525

well while im at WOT im going 13 but like after 10 sec while im at wot it just pulls to 18 psi and just stays till i let the pedal off , tryed to search about my boost changing pressure but couldn't find anything,and im running small 16g Turbo

 

[Darknight968]

yea your problem right now is boost creep. just need to port.

 

[LTUDSM]

is it better to go with external wastegate setup then porting turbine housing???

 

[wvturbo2]

it's best not to put any dsm in a pool they won't run at alll. Maybe if u take it out of the pool and dry everything out itll run alot better. Just try to keep it out of lots of water like that.
An external wastegate will give you better performance than internal, but i would just do like they say and port the turbo since its already internally gated

 

[LTUDSM]

well i ported the turbohousing and o2 sensor as much as i could,but i still got a boost creep,what do you guys suggest me to do??? im totaly lost

 

[fwdeclipse]

Did you follow this link http://dsmtuners.com/forums/showthread.php?t=186525 Or did you just port it bigger around everywhere.You need to take off where the wastegate hole is so the exhaust has no choice but to go that way.

 

[LTUDSM]

Did you follow this link http://dsmtuners.com/forums/showthread.php?t=186525 Or did you just port it bigger around everywhere.You need to take off where the wastegate hole is so the exhaust has no choice but to go that way.

what do you mean by taking off the wastegate hole??? you mean from inside turbohousing that wastegate entrance??? if yes i grind that away

 

[olmytsi]

I know a dsmer that lives in your town in case you are looking for local help. Let me know.

 

[LTUDSM]

I know a dsmer that lives in your town in case you are looking for local help. Let me know.

tell me that would be great,BTW what kind of dsm he got??

 

[olmytsi]

He doesn't have one at the moment but he definitely knows his shit. You should register on the phillydsm forums and you can pm him on there. www.philadelphiadsm.com his name is Joe and his screename is noreaga0221...he is a moderator.