sr cutting out

[uhhh-s13 again]

ill try and give all the i can think of to help pin point it. recently my sr has been bogging while cruising, and when i push the gas it will still bog for a second and then get over it. (this all started when i cut my muffler of and went 3in straight pipe, but not sure why that would do anything besides loosing a little bottom end power). tonight i was driving and it was getting really bad it would totally cut out and backfire really bad. (its been backfiring a little lately but not like this). i dont have a wideband but im pretty sure im running rich. totally stock sr with 3in downpipe and exhaust with front mount, cone filter intake. my maf is located on my cold pipe about 8 in before the throttle body but has been for like 4 months now and i havnt had any problems with that(just giving details on setup). also my bov doesnt return to intake. i cleaned my maf a few months ago. i put a boost gauge in tonight and its running at 8psi, one time reached 9psi in 3rd gear. iv only driven about ten miles with the boost gauge in so i havnt had much time to watch it. it doesnt do it all the time except when i drove it tonight it was doing it alot. kindof been getting worse till tonight it got really bad i also put new plugs in tonight and gabbed them at .033. you think cutting my muffler and running a straight pipe is the cause. im getting it welded back on tomorrow i wasnt planning on leaving it off just seeing what it was like. any thoughts would be helpfull.

[uhhh-s13 again]

now my car will start and run for a few min just fine. then it will start cutting out and bogging down to were it will barely idle then i turn it off. i checked the fuel injectors they om out at around 12.2. the coil packs are at 1.7 to 2.2. cleaned the maf. i pulled the spark plugs that i just put in and ther white? could removing my muffler be causing to much flow and not enough fuel?

[Seishuku]

The exhaust shouldn't have that kind of effect on the fueling, a mass air flow system (like what Nissan uses) will automatically correct for air flow changes to the system (ie. free flowing exhaust and intake) to a point (usually when the injectors or air flow sensor is maxed out), then you start running into constant lean areas.

Sounds more likely that you have a boost or vacuum leak somewhere, that is leaking out air that the air flow sensor has already metered.

[uhhh-s13 again]

i didnt think of that ill check and see what i can find. thanks for helping.

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i cant find any leaks. now i start the car and it will run really nice at first, then like a minute later you hear it starting get choppy, then it will just die.

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i checked the tps and got 0 volts out of it. shouldnt it be around 4.5?

[Seishuku]

i checked the tps and got 0 volts out of it. shouldnt it be around 4.5?

Should be .4 closed and 4.8 fully open.

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ok ill check tomorrow. thanks again for your help.

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might be a stupid question but is that with the car off?

[Seishuku]

Yep, well... Ignition on, engine off.

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its my fuel pump. i was reading about the walbro fuel pumps and they recommend that you have a at least a half tank at all times to insalate the fuel pump and keep the temperature down. i run my car all the time less then half full. when i checked it i had 7psi of fuel pressure lol. problem solved new walbro ordered.