Should I be worried or is normal? for new motor.

[BMWM3]

I just had a new built stroker motor with procharger installed in my car. The car everyone so often while i'm driving the wideband gauge will jump from 10 to 20 back and forth and back and forth. In order to get it to stop I take my foot off the gas and then the wideband gauge goes back to normal around 14.7 to 13.8 when normal driving at around 1200rpm to 1900rpm doing about 35mph to 55mph. I'm still on break in tune, the car still needs about 350miles more in order to hit break in of 500miles. Is this normal for new motor that still on break in tune or should I be concerned.


My build consist of 5.0 stroker, dss stage 2 ported heads, stock cams, procharger p1sc, new twindisk clutch and flywheel. frpp manifold and other supporting modes

 

[TexasBlownV8]

The afr is affected by tuning. Normally, the pcm will alternate between rich and lean under normal driving. The tune will affect the extent of those variations.

 

[stkjock]

does it jump as you get on and off the throttle?

 

[Fullboogie]

Have you bothered to datalog?

 

[skwerl]

The softer you break it in, the weaker the motor will be. Had mine on the dyno after 225 miles and at the track after 300 miles. 90% of your break in is done in the first 20 minutes.

Time to get it back to your tuner and get the tune nailed down.

 

[psfracer]

I had mine on the engine dyno turning 7800 rpm after about two heat cycles getting up to operating temp (about 20 minutes combined).

 

[RocketcarX]

What's a break in tune? You should have cranked it up, checked fluids and drove it like you stole it. Sounds like you are too lean at every RPM, but scary up top.

http://www.mototuneusa.com/break_in_secrets.htm

 

[BruceH]

I just had a new built stroker motor with procharger installed in my car. The car everyone so often while i'm driving the wideband gauge will jump from 10 to 20 back and forth and back and forth. In order to get it to stop I take my foot off the gas and then the wideband gauge goes back to normal around 14.7 to 13.8 when normal driving at around 1200rpm to 1900rpm doing about 35mph to 55mph. I'm still on break in tune, the car still needs about 350miles more in order to hit break in of 500miles. Is this normal for new motor that still on break in tune or should I be concerned.


My build consist of 5.0 stroker, dss stage 2 ported heads, stock cams, procharger p1sc, new twindisk clutch and flywheel. frpp manifold and other supporting modes

What are the fuel trims doing at this time? The ecu uses stft to correct any differences between fueling that's predicted by the maf signal and what the o2 sensors are reading. If the short term fuel trims are swinging wildly I'd be concerned. One thing that happens is the o2 sensor wires get swapped and put the correction on the wrong bank. I'm not saying that is happening, it's just an example.

 

[AutoXRacer]

Take it from someone that has to tear apart his engine after one year of use...
BREAK IT IN HARD!!!

Do the 20-25 mins initial break-in, dump the oil, fill it back up with fresh oil and filter, then HAMMER IT on the dyno (cause its safer than on the street)!!!!

I have been told it only takes 2-3 pulls and make sure you let the motor slow down on its own, no brakes just engine vacuum.

Then you should be good...

BTW, that tune sounds a little off...
What injectors are you running?

 

[sportinawoody]

i had this issue after having my axle tubes welded even though i had the battery unhooked. culprit was my wideband sensor. it would go haywire just like that even though the car ran perfect and under w.o.t. it pegged lean. in the case of forced induction a car wouldnt even run at all with a 20:1 afr under wot so get a sensor and be done with it

 

[Redrocket06]

What are the fuel trims doing at this time? The ecu uses stft to correct any differences between fueling that's predicted by the maf signal and what the o2 sensors are reading. If the short term fuel trims are swinging wildly I'd be concerned. One thing that happens is the o2 sensor wires get swapped and put the correction on the wrong bank. I'm not saying that is happening, it's just an example.

+1
Also what does the motor do during this? If no change is felt or heard from the motor then I would start looking at the wideband for issues. If the motor bogs/surges during that time then let the tuner know, maybe it could be solved with a tune revision.

 

[01yellerCobra]

The softer you break it in, the weaker the motor will be. Had mine on the dyno after 225 miles and at the track after 300 miles. 90% of your break in is done in the first 20 minutes.

Time to get it back to your tuner and get the tune nailed down.

Amen. Once mine was warmed up it saw full boost. And it turned 100 miles on the dyno. It's a strong motor now.

Misspelling brought to you by tapatalk

 

[JimIII@JDM]

How old is the wide band gauge's sensor, if its old or damaged (maybe you blew your old engine and it got covered in oil/coolant?) then it will skew the readings like your seeing. If your air fuel is jumping between 10-20 you would feel it and your drive ability would be pretty bad. Start with the sensor, if not then put it on the dyno and make sure your getting and accurate reading.

 

[Redrocket06]

^^ this, op never said motor ran poorly.

 

[sportinawoody]

How old is the wide band gauge's sensor, if its old or damaged (maybe you blew your old engine and it got covered in oil/coolant?) then it will skew the readings like your seeing. If your air fuel is jumping between 10-20 you would feel it and your drive ability would be pretty bad. Start with the sensor, if not then put it on the dyno and make sure your getting and accurate reading.

amen brother,,, thats what i was trying to tell him.

a car wouldnt even run at all with a 20:1 afr under wot so get a sensor and be done with it

 

[BMWM3]

Have you bothered to datalog?

No I have not datalogged yet. Good idea I will do it and provide data to my tuner.

What's a break in tune? You should have cranked it up, checked fluids and drove it like you stole it. Sounds like you are too lean at every RPM, but scary up top.

http://www.mototuneusa.com/break_in_secrets.htm

I wll read the link shortly

Take it from someone that has to tear apart his engine after one year of use...
BREAK IT IN HARD!!!

Do the 20-25 mins initial break-in, dump the oil, fill it back up with fresh oil and filter, then HAMMER IT on the dyno (cause its safer than on the street)!!!!

I have been told it only takes 2-3 pulls and make sure you let the motor slow down on its own, no brakes just engine vacuum.

Then you should be good...

BTW, that tune sounds a little off...
What injectors are you running?

60lb injectors

How old is the wide band gauge's sensor, if its old or damaged (maybe you blew your old engine and it got covered in oil/coolant?) then it will skew the readings like your seeing. If your air fuel is jumping between 10-20 you would feel it and your drive ability would be pretty bad. Start with the sensor, if not then put it on the dyno and make sure your getting and accurate reading.

Wide band guage is about two years old, bought it when it was a twin screw, blew the motor on twin screw then went got a block from junkyard and bought 5.0 rotating assemlby and ported stage 2 heads with stock cams. behind procharger... I do feel it in my driveability the car jerks and only way to stop it is when i through it in neautral then it goes normal and does this intermittantly maybe once or twice if I drive it about 15 or so miles.. I only have 157 miles on New motor and new clutch.. How many miles should i put on clutch before i get final tune.

^^ this, op never said motor ran poorly.

When it runs right it runs great

does it jump as you get on and off the throttle?

It jumps while on throttle when i let off it does not jump

 

[Redrocket06]

I would suggest a new sensor, no telling if it was damaged when the motor popped. Calibrate it before dataloging. With the motor acting up when it happens I would check all vacuum connections and hoses for leaks, cracks, cuts and all the intake piping for leaks after the maf. Did your tuner send you a configuration that they want used as well as a formula for the Analog 1 wideband?

I put 500 miles of stop and go driving, and when I got on a long stretch of road I would shift between 4th and 5th, just to keep it changing. Called it good after 500 miles.