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Discussion Starter · #1 ·
i got a 1996 impala ss stock lt1 with a rebuilt 460le with shift kit, all are a year old- spark plugs, wires, Accel 26lbs 14.4 ohms Impendance fuel injectors,duralast EGR. its got a flowmaster exhaust on it and a 160 degree stat. thats pretty much it. my dad said brand new the car would burn rubber on a green light now it takes off slow, i guess what im saying i have no power at low rpms then it used to have. just wondering what i could do to fix it???
 

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From a diagnostic standpoint, have you changed the fuel filter recently? The change to E10 in most parts of the country dropped power levels and gas mileage by about 5 %. I wouldn't put it past the fuel stsyem to be at fault. I would seriously look the engine over and correct any vacuum leaks, such as the 1/2 ID tube that attatches the crankcase breather to the throttle body on the passenger side, the 90 degree piece of preformed rubber hose under the throttle body for the pcv valve, the pcv valve itself, the opti vent vacuum harness, and a good throttle body cleaning. If an oil on gauze filter like a K and N is used excessive oil could be on the MAF wires, a gentle cleaning with some MAf cleaner and a q tip work well here. A fuel pressure test can be performed, accept no less than 39 psi on an idling engine and with vacuum removed from the regulator at least 43. If pressure drops off immediately after key off, then an injector may be leaking, but most likely its the check valve for the pump in the tank. If you have to do a pump, replace the in tank harness. Its available from napa for about 20 bucks. Strongly consider a fuel pump wiring harness upgrade for the vehicle. I would even consider it an necessary upgrade even if you find nothing wrong with the fuel system.

Anything else, or need to add to the troubleshooting data, just post up!

Chris
 

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Discussion Starter · #4 ·
I've got a new GM fuel pump in it now, pressure is around 39 40. im thinking there's some carbon on the valves maybe? the cars got 130,000 miles on it. it could be the opti but ive put a new one in a year ago but it was from auto zone,plugs and wires are about a year old too. ive thought about changing to alum heads that have been cleaned new seals and maybe resurfaced and 1.6 RR. is the rockers set at zero lash?

appreciate any help i can get!
 
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