Hello For All The People That Remember Me, Its Been A While, My ZJ Is Having A Issue, That I Need Help With, The Problem Is When Im At A Dead Stop, Then Do A Hard Launch Everything Is Fine Until The Tach Gets To Aprox 3000 RPM (+ or - 100 RPM), The Engine Power Dropps Off Drasticly Then Picks Back Up Less Than A Half Second Later, And Repeats This Until Either The Tranny Kicks Into Second Or I Let Off The Gas, It Also Happens At The Same RPM If Crusing Down The Highway And Then Stomping It Into Passing Gear, Basicly It Does This Every Time I Go Over 3000 RPM, Unles I Baby It Past 3000 RPM (Depressing Slowly On the Gas), Well I Thought Fuel Blockage, So I Checked Fuel Pressure, 40 PSI @ Idle And Steady Needle, Dropps Only 2 PSI When Revving Engine, From The Haynes Manual this Is Good, Fuel Filter Was Also Replaced, So Then I Figured Ignition System, Replaced Coil, Plugs, Wires, Cap, Rotor, Distributor, With No Luck... Then Tested All Sensor's, I Have Recently Replaced The O2 Sensor & The TPS As They Went Bad. Next I Checked Voltage At The PCM, Checked The Grounds To The PCM. No Luck... Then Installed A Vaccuum Gague On The Dash, Steady @ 20 In Hg, Goes To 23 When Engine Is Revved, After Shutting Engine Off This Pressure Starts To Drop In Aprox 15 to 20 Minnutes, And Is Completely @ 0 After About An Hour.. Compression Check Gives 142 PSI @ The Highest And 139 PSI @ The Lowest, Oil Pressure Reads 18 PSI @ Idle & 67 PSI @ 2000 RPM, Cylinder Leakdown Test Shows Good... Also Note This Is A 4.0L With A Brand New (5000 Miles Old) 42re Auto Tranny Behind It, This Engine Has 160K On It And Has Been Well Taken Care Of, Also This Engine Idles Rough Like The Rotor Is Arcing/Hitting The Distributor Cap But Is Not And Is Brand New... Only Thing I Havent Checked Is The PCM Itself, But Is Not Throwing Codes, But Is Trowing Codes When Some Sensors Are Tested, And That Is Supposed To Happen, But Under Normal Conditions No Codes Are Present, Also Have Not Checked Fuel Injectors, But From What I Understand Having 1 or 2 Bad Injectors Will Cause Totaly Differnt Problems Then I Am Experencing... Someone Please Help!!!!
As I Am About To Lose My Mind!!!
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PS: This Problem Only Applies When Under Load, Engine Will Rev All The Way When In Neutral, If Gas Is Presed Slowly, But If Stomped Real Quick It Will Studder Then Rev, Then Miss Once Or Twice Then Rev all The Way Up, But Sometimes When Stomped It Doesnt Do Anything But What Its Supposed To... Weird....
Im Thinking PCM... Any Comments?
As I Am About To Lose My Mind!!!
PS: This Problem Only Applies When Under Load, Engine Will Rev All The Way When In Neutral, If Gas Is Presed Slowly, But If Stomped Real Quick It Will Studder Then Rev, Then Miss Once Or Twice Then Rev all The Way Up, But Sometimes When Stomped It Doesnt Do Anything But What Its Supposed To... Weird....
Im Thinking PCM... Any Comments?
