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27 Posts
1999 Chev 'Burb. K-1500 5.7L/4L60E/3.42 rear. 82,000 miles.
Replaced the 2bolt main in my burb last month with a 4 bolt re-man as the old engine had spun a rod bearing. New engine dropped in easier than pulling the old one. Now has 850 miles on engine. Replaced Engine, radiator, waterpump, All filters, exhaust with shorty headers (edelbrock), all gaskets on intake were replaced, all hoses including heater hoses up to the split for rear/front, clamps, battery cables to engine were fabricated from 0 gauge welding cable(aux cable fine and not replaced), new coolers, chrome valve covers. Engine painted Chevy orange (can't stand a black small block. Besides I grew up with Tonowanda built small blocks). About the only thing I didn't replace was probably the flywheel.
ANYWAY. Had an Electrical problem last week where it cut out and died. T/S it and found the Connection on the PCM had come loose, and the Crank Posit Sensor(CPS) had died. Cleaned the contacts-reconnected the plug to the PCM and replaced the CPS. No SES light(Good). Runs great except when it hits just above 3000 and it cuts in and out, spits out thru the intake, bucks like a mad bull, and the tach goes wacko. As soon as I drop the revs, it reverts back to normal/
Haven't gotten into it yet, but I'm thinking possibly Plug wires arcing (they shouldn't as I replaced them with the engine and routed them exactly as the old ones.). or the coil/ignition module is acting up. I did the testing per Haynes manual for checking the coil, ign. mod., wiring, prior to getting to isolating down to the CPS. Everything checked out ok. No burns or rub marks on the plug wires. I have corrugated split loom tubing on all wires from end to end. No melting or evidence of burning near the Edelbrock shorty headers. Resistance is within spec for each wire. Distributor cap and rotor are new.
Fuel pressure is 63 with engine off and 55 with engine running. New fuel filter, air filter, PCV Valve, pulling 18" vacuum at idle and 21"@2000. Compression is equal @ 165-170 across the board. No valve taps, oil leakage on to any wiring. All connections are tight and verified by VOM.
Anyone got any other ideas??? Thanks.
Larry
Replaced the 2bolt main in my burb last month with a 4 bolt re-man as the old engine had spun a rod bearing. New engine dropped in easier than pulling the old one. Now has 850 miles on engine. Replaced Engine, radiator, waterpump, All filters, exhaust with shorty headers (edelbrock), all gaskets on intake were replaced, all hoses including heater hoses up to the split for rear/front, clamps, battery cables to engine were fabricated from 0 gauge welding cable(aux cable fine and not replaced), new coolers, chrome valve covers. Engine painted Chevy orange (can't stand a black small block. Besides I grew up with Tonowanda built small blocks). About the only thing I didn't replace was probably the flywheel.
ANYWAY. Had an Electrical problem last week where it cut out and died. T/S it and found the Connection on the PCM had come loose, and the Crank Posit Sensor(CPS) had died. Cleaned the contacts-reconnected the plug to the PCM and replaced the CPS. No SES light(Good). Runs great except when it hits just above 3000 and it cuts in and out, spits out thru the intake, bucks like a mad bull, and the tach goes wacko. As soon as I drop the revs, it reverts back to normal/
Haven't gotten into it yet, but I'm thinking possibly Plug wires arcing (they shouldn't as I replaced them with the engine and routed them exactly as the old ones.). or the coil/ignition module is acting up. I did the testing per Haynes manual for checking the coil, ign. mod., wiring, prior to getting to isolating down to the CPS. Everything checked out ok. No burns or rub marks on the plug wires. I have corrugated split loom tubing on all wires from end to end. No melting or evidence of burning near the Edelbrock shorty headers. Resistance is within spec for each wire. Distributor cap and rotor are new.
Fuel pressure is 63 with engine off and 55 with engine running. New fuel filter, air filter, PCV Valve, pulling 18" vacuum at idle and 21"@2000. Compression is equal @ 165-170 across the board. No valve taps, oil leakage on to any wiring. All connections are tight and verified by VOM.
Anyone got any other ideas??? Thanks.
Larry