Hello all!
Make/Model:2000 Cadillac Escalade
Engine: 5.7 LQ4
History:The truck in the past dropped idle every 15-30 secs at about 100 rpms for less than a second (like a misfire) thought maybe it would be a Idle Air Control Valve Replaced it with no positive outcome. The trucks misses in idle quality has eventually become worse to where it falls within the idle harmony of the truck (imagine putting a crap lobed designed cam in the truck with high lift and duration at idle) it appears to possibly be a bad cap and rotor along with plugs but I don't want to omit a TPS sensor of MAF sensor going crap either. The truck is throttled by a drive by wire. Yes it has the crap spider assembly, but I replaced it with the $400 Delphi system along with a new fuel pump and fuel filter. The truck appears to have good evaporate canister and lines to it from the tank the EGR vaccum line committed suicide so I replaced that along with a cleaning of the EGR and throttle body. I have replaced the "O" rings in the purge solenoid and checked connections in all vacuum lines. The plug wires show no burn through but that does not make them perfect. I have not yet sprayed carb cleaner around the intake manifold and the plenum but I'm about to soon. I don't believe those to be of issue though since the truck runs better than what that would possibly present when it leaks. The truck cruises fine past 1500 rpms but fluctuates in idle below that range.
Thoughts: I'm leaning more towards a bad MAF, TPS and O2 sensors or a worn plug, wires, cap and rotor set. What do you guys think? Thanks for your help and input in advance! -Caddy
Make/Model:2000 Cadillac Escalade
Engine: 5.7 LQ4
History:The truck in the past dropped idle every 15-30 secs at about 100 rpms for less than a second (like a misfire) thought maybe it would be a Idle Air Control Valve Replaced it with no positive outcome. The trucks misses in idle quality has eventually become worse to where it falls within the idle harmony of the truck (imagine putting a crap lobed designed cam in the truck with high lift and duration at idle) it appears to possibly be a bad cap and rotor along with plugs but I don't want to omit a TPS sensor of MAF sensor going crap either. The truck is throttled by a drive by wire. Yes it has the crap spider assembly, but I replaced it with the $400 Delphi system along with a new fuel pump and fuel filter. The truck appears to have good evaporate canister and lines to it from the tank the EGR vaccum line committed suicide so I replaced that along with a cleaning of the EGR and throttle body. I have replaced the "O" rings in the purge solenoid and checked connections in all vacuum lines. The plug wires show no burn through but that does not make them perfect. I have not yet sprayed carb cleaner around the intake manifold and the plenum but I'm about to soon. I don't believe those to be of issue though since the truck runs better than what that would possibly present when it leaks. The truck cruises fine past 1500 rpms but fluctuates in idle below that range.
Thoughts: I'm leaning more towards a bad MAF, TPS and O2 sensors or a worn plug, wires, cap and rotor set. What do you guys think? Thanks for your help and input in advance! -Caddy
