Hard start after refuelling

[machster]

The last couple trips to the gas station resulted in the car not wanting to start. I had to pump the gas a bunch of times and then it would start. Between fill ups is fine. Also, i am hearing a resonating sound when RPMs are lowering coming from the area of the gas cap. I swapped out the cap and it is still making the sound. Furthermore, i am getting two dtc codes of P1128 and P1130

[JFP in PA]

The last couple trips to the gas station resulted in the car not wanting to start. I had to pump the gas a bunch of times and then it would start. Between fill ups is fine. Also, i am hearing a resonating sound when RPMs are lowering coming from the area of the gas cap. I swapped out the cap and it is still making the sound. Furthermore, i am getting two dtc codes of P1128 and P1130

 

You have an air leak somewhere, the codes indicate that both banks are running so lean that the DME can no longer compensate.  Based upon the sound you describe, I'd start by looking at the EVAP system which is adjacent to the fuel filler in the passenger side front wheel well.  Do a search, there have been postings with photos about this system and its potential leak points.

[NewArt1]

Yes, I have this same problem. A search will reveal numerous posts that cover this topic but I have yet to find the solution. I have changed the gas cap, changed the gas tank bleeder valve ( attached to the filler tube), tested the valves with my Durametric and vacuum gauge, and blew out the lines with compressed air. Same old.

[mikefocke]

Curiously these same 2 codes can mean (in the 7.2 world) either too lean or too rich.  Basically something is sending a signal that the ECU uses to compute the air/fuel adaptation and the computation puts the result outside the proper range.

 

If lean:

 

– Incorrect signal from MAF sensor
– Intake air system leaking
– Fuel pressure too low
– Volume supply of fuel pump too low
– Fuel injectors fouled

– Exhaust system leaking

 

If rich:

 

– Incorrect signal from MAF sensor
– Fuel pressure too high
– Fuel injector leaking
– EVAP canister purge valve open

[NewArt1]

I think that the "hard starting/coke bottle whistle" and the presence of these codes are not necessarily related ( correct me if I am wrong).

I have the former situation but not the latter. JFP is probably right for the codes. Try spraying some carb cleaner at the various air connections in the engine bay with the motor idling. If it stumbles or increases in RPM, you've found your problem.

[san rensho]

Take a look at this

 

http://986forum.com/forums/performance-technical-chat/50264-success-finally-fixed-hard-start-while-hot-fueling-issues.html

[machster]

Take a look at this

 

http://986forum.com/forums/performance-technical-chat/50264-success-finally-fixed-hard-start-while-hot-fueling-issues.html

 

The last couple trips to the gas station resulted in the car not wanting to start. I had to pump the gas a bunch of times and then it would start. Between fill ups is fine. Also, i am hearing a resonating sound when RPMs are lowering coming from the area of the gas cap. I swapped out the cap and it is still making the sound. Furthermore, i am getting two dtc codes of P1128 and P1130

The problem is fixed. Sunset Imports suggested I look at the Vent Line from the Manifold. Swapped out with a new one and the problem is gone.