rpms surging during cold start. wtf?
rpms surging during cold start. wtf? the car had a hard time starting up today. when I usually start the car I hear a healthy VROOOM and the rpms jump up to about 1100 and settle around 700.
today, the car seemed like it was having trouble. the rpms were at around 400-500 when it started and then jumped to about 1200. a few seconds later it was back at 700.
yesterday, when I was cruising along at 30mph I felt a sudden loss of power for a second. almost like the ASR had engaged and stoped the throttle but my foot never left the gas pedal it also happend once again today.
I dont know what the hell is going on. I took the car to a huge parking lot near my house and did some laps around it for a while trying to duplicate the power loss I experienced earlier. I did not manage to get the car to surge again....so I cant really describe the symptoms in detail. it almost seems like the car stumbles for a second and then picks itself back up.
the car is a 2000 Z 6speed, lid, pulley, Jet-hot LTs and GMMG. the header have been on for about a year and I have not had any tuning done.
The car has three codes right now...but the SES light is NOT on.
p0135 02S Heater Curcuit Bank 1 Sensor 1 malfunction
p0141 02S Heater Curcuit Bank 1 Sensor 2 malfunction
p0155 02S Heater Curcuit Bank 2 Sensor 1 malfunction
I have an exhaust leak in my y pipe. I dunno if this has anything to do with it. thanks!
today, the car seemed like it was having trouble. the rpms were at around 400-500 when it started and then jumped to about 1200. a few seconds later it was back at 700.
yesterday, when I was cruising along at 30mph I felt a sudden loss of power for a second. almost like the ASR had engaged and stoped the throttle but my foot never left the gas pedal it also happend once again today.
I dont know what the hell is going on. I took the car to a huge parking lot near my house and did some laps around it for a while trying to duplicate the power loss I experienced earlier. I did not manage to get the car to surge again....so I cant really describe the symptoms in detail. it almost seems like the car stumbles for a second and then picks itself back up.
the car is a 2000 Z 6speed, lid, pulley, Jet-hot LTs and GMMG. the header have been on for about a year and I have not had any tuning done.
The car has three codes right now...but the SES light is NOT on.
p0135 02S Heater Curcuit Bank 1 Sensor 1 malfunction
p0141 02S Heater Curcuit Bank 1 Sensor 2 malfunction
p0155 02S Heater Curcuit Bank 2 Sensor 1 malfunction
I have an exhaust leak in my y pipe. I dunno if this has anything to do with it. thanks!
Originally Posted by WILWAXU
Lets see if the guys over here can help out.
the loss of power thing happened to me again last night on the freeway.
it almost feels like the car is running out of gas but there was plenty in the tank. I also noticed that the rpms do not surge or change when the loss of power happens.
To me it sounds like your o2's aren't getting hot enough causing the fueling to be off on the car. The little bit of extra air that the car is seeing because of the leak could be hindering them from staying warm. I would swap to a new set of o2's and fix the leak. JMO
****UPDATE****
Problem solved! I did some searching on the other boards and I found a thread where a guy had a very similar problem and it turned out to be his ECT sensor was bad. I went ahead and checked mine and it was loose!! I was also getting a P0118 and a P1115 code (both have to due with the ECT sensor). I originally damaged the sensor lock when I did my LT install, so that would explain why it came loose.
I pluged the ECT back in, flashed the PCM and took her for a 30 miunute drive. Shes running strong again!
Now all I have to deal with is the o2 codes that will eventually come back I guess I need to get a tune and have them tuned out.
Problem solved! I did some searching on the other boards and I found a thread where a guy had a very similar problem and it turned out to be his ECT sensor was bad. I went ahead and checked mine and it was loose!! I was also getting a P0118 and a P1115 code (both have to due with the ECT sensor). I originally damaged the sensor lock when I did my LT install, so that would explain why it came loose.
I pluged the ECT back in, flashed the PCM and took her for a 30 miunute drive. Shes running strong again!
Now all I have to deal with is the o2 codes that will eventually come back I guess I need to get a tune and have them tuned out.
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
Originally Posted by LS1TechRulez
Now all I have to deal with is the o2 codes that will eventually come back I guess I need to get a tune and have them tuned out.
If the Front O2 codes come back (bank 1 sensor 1, bank 2 sensor 1) you don't want to turn these off... if they come back then there's a problem... I'd check the ENgine Sensor fuse first thing... if a O2 sensor wire hits a header and melts through it'll blow this fuse...
Do you have O2 Extensions on both front O2 sensors? if so you may want to switch to some BOSCH or Denso replacement sensors from a vette (seems to solve a large majority of O2 heater errors)
Originally Posted by horist
If the Front O2 codes come back (bank 1 sensor 1, bank 2 sensor 1) you don't want to turn these off... if they come back then there's a problem... I'd check the ENgine Sensor fuse first thing... if a O2 sensor wire hits a header and melts through it'll blow this fuse...
Do you have O2 Extensions on both front O2 sensors? if so you may want to switch to some BOSCH or Denso replacement sensors from a vette (seems to solve a large majority of O2 heater errors)
Do you have O2 Extensions on both front O2 sensors? if so you may want to switch to some BOSCH or Denso replacement sensors from a vette (seems to solve a large majority of O2 heater errors)
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Originally Posted by LS1TechRulez
no O2 extensions. The jet hot headers have the O2 bungs on the inside of the pipe so the O2 sensors stay in the stock locations. I have checked the wires and everything looks good. I did a good job of tucking them away when I installed the LTs.
I have Jet Hot Headers, you need the extensions, period! Sounds like you might be using your rear O2 wires instead....
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i deleted my heater codes, the car runs the heater test on the o2s and with headers it takes longer to heat up than the test allows for so it throws the code, when if the test was about 30 sec longer it woudl be fine. i turned the p0155 and p0135 off. but do this only if you have headers and your o2s are opperating fine under operating temps