loss of power
#1
Senior Member
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Thread Starter
loss of power
first thing in the morning going down the street hit the gas it will spin the tires. after normal operating temp car falls down. taking off from a stop sign it acts like its running out of gas just lays down no power. 99 3.8L non turbo. parts replaced fuel pump and filter unkown miles on that . plug wires plugs air filter new tps. has different mass air flow sensor not a new one . did the same thing with the old one to. forgot no check engine light
Last edited by 99 bonnevillegreen; 07-10-2009 at 10:11 PM.
#2
Just so we don't repeat anything that you have replaced already......
How old is the O2 sensor?
When you take off from a stop do you notice any hissing sound coming from your cat converter?
A bad O2 sensor would decrease power and a plugged cat would also.
But since you said it loses power after its warmed up then it could also be a IAC sensor.( Idle Air Control Valve )
IAC sensor will affect the way the motor runs when its going bad.
Do a quick test the next time it acts up. Pop the hood and tap on the IAC sensor to see if engine power returns for a sort while.
Look for the sensor on your throttle body that looks like this where it plugs into the wire harness to find it:
What brand of fuel pump did you have put in?
The only reason I ask is because a bad fuel pump would also decrease power when its warmed up as well.
Have you checked your fuel pressure when the motor acts up?
parts replaced fuel pump, filter unknown miles on that . plug wires, plugs, air filter , new tps. has different mass air flow sensor .
When you take off from a stop do you notice any hissing sound coming from your cat converter?
A bad O2 sensor would decrease power and a plugged cat would also.
But since you said it loses power after its warmed up then it could also be a IAC sensor.( Idle Air Control Valve )
IAC sensor will affect the way the motor runs when its going bad.
Do a quick test the next time it acts up. Pop the hood and tap on the IAC sensor to see if engine power returns for a sort while.
Look for the sensor on your throttle body that looks like this where it plugs into the wire harness to find it:
What brand of fuel pump did you have put in?
The only reason I ask is because a bad fuel pump would also decrease power when its warmed up as well.
Have you checked your fuel pressure when the motor acts up?
#3
Senior Member
Posts like a 4 Banger
Thread Starter
o2 sensor not sure how old. no hissing niose from cat. iac motor looks like factory one. fuel pump gm / bosch pump in gm box. by the time i get home from when it does it its running ok but not like in the morning. wish i could get a cel then might have some direction to look. how nuts is that want a cel
Last edited by 99 bonnevillegreen; 07-11-2009 at 06:28 AM.
#4
iac motor looks like factory one.
Some have tried just taking out the sensor and cleaning it with break clean. The plunger inside does get all carboned up. Cleaning may be a long shot but might work until you can buy another one.
#5
wish i could get a cel then might have some direction to look. how nuts is that want a cel
PM me if you want to do that, and I'll call you or have them call me sometime.
#8
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Thread Starter
put on new iac ran great. now the vacuum falls off going up a hill dont have to be steep either. with the ac on and blow through the deffrost vent. after 40 min ride back to same old thing turned off highway went to make my turn and flat like an old style carb would lay down . starting to make me crazy
#10
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Join Date: Dec 2008
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my guess is either that pump is either crap or your fuel guage is screwing with you.... here what happened to me one time
I was around half a tank until i hit the ramp towards the highway, and it decides to cut out!! after pulling to the side it kicks back in and im off. The ramp was a downwards right slope, realized that my fuel guage was *****n with me so now i keep her full
I was around half a tank until i hit the ramp towards the highway, and it decides to cut out!! after pulling to the side it kicks back in and im off. The ramp was a downwards right slope, realized that my fuel guage was *****n with me so now i keep her full