2000 454 chevrolet engine.

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#1
i have a 2000 model winnebago m/h,454 gas engine. when cold it fires up beautiful,when warm or normal temp it acts as if its flooded. i have a new engine from gm (they installed it). the old engine was doing the same thing. 454 with sfi all the electronics. the old motor had 72,000,the new one has only 1,000. no codes and engine runs perfect other than warm start,also has a new gm fuel pump. i hope this the right forum. thanks.
 

billr

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#2
Does this have an OBD system, CEL working, any codes set? My first suspicion is the ECT sensor system. I'm really surprised an engine with only 72K miles was changed out for only hard hot-starting; did I read that correctly? When the engine was changed out, were all the sensors, injectors, ignition, intake system, etc. changed as well; or was it a "long block" where most of existing was re-used?
 
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#3
agree with bill - something seams missing.. new engine for starting issue?

warranty? what does dealer say? more questions than answers
 
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#4
the old engine blew a head gasket and bent a rod locking the engine up. it is an obd2 and no codes. 02 sensors was replaced with engine and antiknock sensor. i've had this m/h over a year and has always had warm start issue.
 

billr

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#8
If it is OBD2, put a scan-tool on it and look for live-data, especially the ECT. Note, the problem might not be a sensor itself, but the wiring form it to the PCM.
 
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#9
the scanner will be a must here, and not the limited so called GENERIC CODE READERS.
START with BASICS - fuel pressure, Fuel press leaking down test, Vacuum, ECT,


My experiance a long block is - built up block and heads, does NO include fuel rail, ignition, intake, exhaust, or 'tin' valev cover, oil pan, etc.... I might be wrong ... BUT I am thinking the hard start issue transfered with the shared components- old to new.
 

billr

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#10
Yep, I agree. An even worse scenario is that whatever caused the old engine to hydro-lock and bend the rod (maybe a coolant leak related to intake manifold?) also got transferred... let's hope it was a head gasket, that would have all got changed with the "long block".
 
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#11
:thxthanks guys for all the input.it was the ect sensor,cheap and easy fix so i tried that first and fixed it.thanks again. fixed