poor acceleration

[seth9199]

so recently I've been experiencing a problem wit my 97 k2500 5,7 vortec. Whenever i accelerate hard and get up to speed one or two times or push the truck. i start to have a super slow acceleration issue like its bogging down almost but it still seems to downshift with the lack of power. it only has 110,000 miles. i'm thinking either fuel pressure regulator or fuel pump. i did a pressure test at idle and read 53 psi. issue also happened once after a brake toque. racin my lil bro

 

[seth9199]

Update fuel pressure while driving is good even when it boggs driving. So at this point im clueless

 

[east302]

Any codes stored?

What is the fuel pressure with engine off/ignition on? Spec is 60-66 psi.

A back pressure test may be in order to check for an exhaust restriction or damaged catalytic converter(s). Gauge sets can be had for around $40 or you could rig one together for less. A swivel or 90-el comes in handy if using one of the kits.

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[Christian Steffen]

Do you have a way to datalog anything like throttle pos, MAP, rpms, fuel trims, MAF airflow (in g/s), etc?

 

[seth9199]

Do you have a way to datalog anything like throttle pos, MAP, rpms, fuel trims, MAF airflow (in g/s), etc?

yeah all looks good. i do get running lean codes when it happens. but even when it happens have same fuel pressure as i do when it dosent happen. about 63 psi. is there a possibility it could be o2 sensors?. the codes also go away under basic driving for bout 25 miles.
im almost thinking run anti foulers on the o2s or try new ones.

 

[seth9199]

Any codes stored?

What is the fuel pressure with engine off/ignition on? Spec is 60-66 psi.

A back pressure test may be in order to check for an exhaust restriction or damaged catalytic converter(s). Gauge sets can be had for around $40 or you could rig one together for less. A swivel or 90-el comes in handy if using one of the kits.

You must be registered for see images attach

if it was a clogged cat wouldnt that mean id have the issue all the time?

 

[Christian Steffen]

yeah all looks good. i do get running lean codes when it happens. but even when it happens have same fuel pressure as i do when it dosent happen. about 63 psi. is there a possibility it could be o2 sensors?. the codes also go away under basic driving for bout 25 miles.
im almost thinking run anti foulers on the o2s or try new ones.

Could be o2s.. unplug them both and see what it does. That'll force it to stay open loop. Also if you haven't, clean your maf. Use maf cleaner ONLY

 

[seth9199]

Could be o2s.. unplug them both and see what it does. That'll force it to stay open loop. Also if you haven't, clean your maf. Use maf cleaner ONLY

Replaced the maf all already. Imma try the foulers then if not ill unplug amd see if it continues

 

[Christian Steffen]

Replaced the maf all already. Imma try the foulers then if not ill unplug amd see if it continues

replaced with oem one?

 

[seth9199]

replaced with oem one?

Yup one to one oem. How ever when i unplug maf the issue goes away. So im thinking it may just be the downstream 02s