[tommyc]

Hi all I need a little help with diagnostics. Background, BWR s/c installed 2 weeks ago with charliex tune. Ran awsome. Took a trip to naples and back 2 days 300 miles. I initially broke it in with 100 miles. Got gas after returning hme and check engine light goes on steady. no change in performance. Hooked it up and it was a Po171 code. Cleared the code and cleaned MAF sensor with MAF cleaner. The wires were a little dirty. Now there is a stumbling at mid throttle and the power is way off as if there is no boost. Idles fine and throws no codes. I do hear a wooshing at lift throttle when shifting even though it is warmed up. This used to only happen when cold. Any ideas would be appreciated. I will check for vacuume leak this evening post throttle body as well as line to bypass valve on s/c. Thank you in advance! Tommy

 

[Dragon]

Did you leave a hose clamp loose in your intake pipe? You could be drawing in air that is bypassing the MAF sensor...

 

[Ryephile]

I'd start by looking at everything you touched during the MAF cleaning. P0171 is a lean code, which typically is something where the hardware and/or firmware were changed in a significant manner and the fuel trim can't correct enough. However now the code is gone so is your power, that is strange. Hopefully charliex has better insight.

 

[tommyc]

Hey Dragon no everything is tight throttle body to filter. Thanks for the response. It does feel like a vaccuume leak because if I am at part throttle then push the gas there is a hesitation and a stumle then accelerates but not with much punch.

 

[Dragon]

A few things that could cause your problem are....

Bad fuel pump.
Fouled fuel filter.
Bad throttle position sensor.

I would assume the computer would throw a code for the TPS though. Are you still getting the lean code popping up or has it gone away completely?

 

[tommyc]

Lean code gone away completely. Even checked again and no pending codes.

 

[Dragon]

hmmm, well it was still running fine even though it had the lean code and the actual running issues occurred after you cleaned the MAF. For this reason I would guess the issue lies there. Did you remember to put the white piece of plastic that smooths the air flow to the MAF? That would also cause your issue.

 

[tommyc]

It is not possible to screw up the tune by erasing the fault code is it?

 

[fpitas]

It is not possible to screw up the tune by erasing the fault code is it?

No.

 

[tommyc]

Thanks.

 

[tommyc]

update. Well I did a whole bunch of stuff, spark plugs look good a little brownish haze on the insulators so I took turbo phils advice and coated everything in dielectric grese. Removed and reinstalled MAS. Removed and reinstalled throttle body. Checked compression 215 +-4 across the board. removed breather and pcv lines, no oil! cool. Checked vaccuum line to bypass valve works good. Started let run for 15 min shut off. Took for ride 20 min later and I AM BACK!!!! do not know what I did but probably the dielectric grease solved my problem. Thanks Phil! Btw I am running IK22 denso's and they looked great 0.35mm gap. I also reseated the fuel injectors. They are Bosch and make more noise than original or others I have had such as RC engineering. Well I hope this may help people in the future with s/c installs. It behooves everyone to search and reasearch this site because there is a wealth of information on it it is just not that easy to find quickly but with diligence it can be had! Thank you all for contributing it makes troubleshooting easier. VERRY HAPPY NOW! Tommy

 

[smokin orange]

Whats up with coating everything in dielectric grese (or is it grease). Missed that tread from turbo Phil.

 

[Dragon]

update. Well I did a whole bunch of stuff, spark plugs look good a little brownish haze on the insulators so I took turbo phils advice and coated everything in dielectric grese. Removed and reinstalled MAS. Removed and reinstalled throttle body. Checked compression 215 +-4 across the board. removed breather and pcv lines, no oil! cool. Checked vaccuum line to bypass valve works good. Started let run for 15 min shut off. Took for ride 20 min later and I AM BACK!!!! do not know what I did but probably the dielectric grease solved my problem. Thanks Phil! Btw I am running IK22 denso's and they looked great 0.35mm gap. I also reseated the fuel injectors. They are Bosch and make more noise than original or others I have had such as RC engineering. Well I hope this may help people in the future with s/c installs. It behooves everyone to search and reasearch this site because there is a wealth of information on it it is just not that easy to find quickly but with diligence it can be had! Thank you all for contributing it makes troubleshooting easier. VERRY HAPPY NOW! Tommy

Awesome that you got your car running... It's really hard to troubleshoot a car via the internet, but it can be done... :clap: