Supercharged 95 stumble and surging

[fj8ttec]

Ok cruiser family i dont post much in here or ever for that matter but i need help . Supercharged cruiser with rebuilt engine . I have literally replaced everything and figure this out . Under even light acceleration it has no power . Like its misfiring and surging. Power is trying to come in but wont . Intermittently runs awesome. I am running landtanks new kit for upgraded mas air flow and wrx injectors . It has always had this hesitation but now its amplified. All input sensors and fuel pump replaced . New harness just installed. Help !

 

[jfz80]

With the new harness did you redo or check the extensions for the IAC and TPS ? Or unloom them back far enough to reach their destinations sans extension ?

Usually where i start with stumbling or lack of power on mine. Once was extensions and once was tps itself.

 

[Tools R Us]

Any codes?

 

[fj8ttec]

With the new harness did you redo or check the extensions for the IAC and TPS ? Or unloom them back far enough to reach their destinations sans extension ?

Usually where i start with stumbling or lack of power on mine. Once was extensions and once was tps itself.

Yes i made nice long soldered extensions

Any codes?

no codes . All input sensors replaced

 

[fj8ttec]

Ok cruiser family i dont post much in here or ever for that matter but i need help . Supercharged cruiser with rebuilt engine . I have literally replaced everything and figure this out . Under even light acceleration it has no power . Like its misfiring and surging. Power is trying to come in but wont . Intermittently runs awesome. I am running landtanks new kit for upgraded mas air flow and wrx injectors . It has always had this hesitation but now its amplified. All input sensors and fuel pump replaced . New harness just installed. Help !

So 7 out of 10 times it will run through 1st gear as designed. Shifts to 2nd and after 3k it flat lines and surges . Like its not getting timing or starving for fuel . Other times even just cruising at 40ish i can feel it surging with no power .

 

[flintknapper]

Check your fuel pressure.

 

[fj8ttec]

Yes i need to get an actual psi number . I am definitely leaning towards this being a fuel issue . Pump filter and fpr new . Wondering what others have done to solve issues such as incorrect voltages to fuel pump

 

[flintknapper]

Yes i need to get an actual psi number . I am definitely leaning towards this being a fuel issue . Pump filter and fpr new . Wondering what others have done to solve issues such as incorrect voltages to fuel pump

By checking your fuel pressure we can eliminate the possibility of fuel delivery issues. IF it checks out OK, we can look elsewhere, if it does not...then starts the systematic testing of certain circuits and components.

 

[SammyT96LX450]

Check timing/plug wires and plugs. I had to replace wires and plugs

 

[fj8ttec]

By checking your fuel pressure we can eliminate the possibility of fuel delivery issues. IF it checks out OK, we can look elsewhere, if it does not...then starts the systematic testing of certain circuits and components.

View attachment 2074686

And this goes in place or inline with the fpr ? Where can i find this ?

 

[flintknapper]

And this goes in place or inline with the fpr ? Where can i find this ?

On the 80 series there is no Schrader Valve on the fuel rail to attach a Fuel Pressure Tester to, so we have to put an adapter in line to hook a tester up to. Some folks even leave it in place.

Since we don't need to test your FPR (new) the easiest place to get an idea of what your fuel pump is putting out...is going to be at the front of your fuel filter. In fact, I would replace the fuel filter...while doing this...if it hasn't been done recently.

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[ppc]

You stated you replaced all sensors. Did that include both engine coolant temperature sensors? How about the TPS and fuel pump relay? Have you cleaned, tested and/or replaced the MAF?

 

[fj8ttec]

Ok cruiser family i dont post much in here or ever for that matter but i need help . Supercharged cruiser with rebuilt engine . I have literally replaced everything and figure this out . Under even light acceleration it has no power . Like its misfiring and surging. Power is trying to come in but wont . Intermittently runs awesome. I am running landtanks new kit for upgraded mas air flow and wrx injectors . It has always had this hesitation but now its amplified. All input sensors and fuel pump replaced . New harness just installed. Help !

Sorry for delay in the update on this . Been running through all systems figuring it out . Turns out the fuel system was clogging up quickly . Lots of rust and debris in the tank due to a rusted out vent line on the filler neck . I had already put a new strainer and filter on the truck not long ago . Decided to recheck again and sure enough the strainer was full of rust again . Landtanks kit does lean the system out for better efficiency so it really caused problems for me . Runs like it never has before now . Stronger pulls off the line all through the rpm . Lower engine temps and better fuel economy. Highly recommend that kit for the supercharged trucks out there .