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Hi guys,
It has been a long while since my V8 conversion was completed (with lots of help from guys on this forum) and over the last week I've had some pretty knarly issues since returning from deployment a month ago.
1) cold start, truck idles fine closed loop but once at temp, see note 2.
2) hot start, truck idles rough, smells rich, "barbally" exhaust note, surging/hunting engine speed.
3) drives rough... Poor shifts, surges at idle, hesitation on acceleration, overall loss of power, infrequent stalling, bucking on deceleration.
4) slightest grade and the thing is gutless... Throttle wide open and its putting along. All symptoms can be induced by going up any hill.
I pulled codes and got a series of emissions related DTCs but I always have those. I got a bank 1 lean code (0171) and a HEGO code for bank one... I did not get 0174 (lean bank 2) or a code for that bank's O2 sensor.
I run only upstream O2 sensors and in an attempt to force the ECU to run closed-loop after coming to temp in hopes of narrowing down the issue, I disconnected both sensors but all the issues persist.
I start assessing the usual suspects... Vacuum leak, TPS, PCV Valve, MAF, DPFE, EGR, etc... Long story short - all of its good. I threw on new O2 sensors as I had them sitting around. Ignition and CPS are good. I pulled the upper intake off to check gaskets and to replace vacuum hoses and everything looked good. Lower intake gaskets are new and certainly aren't leaking so grossly that these issues are resulting.
On to fuel... Replaced regulator and filter and the Fuel Pump and EEC relay click with KOEO. I can hear the HP pump on the frame rail whirring but nothing from the lift pump in the tank. Would the truck run without the lift pump running? I believe both pumps get VDC from the same relay order so if one has it the other should... Barring a cut or grounded power wire.
I'm looking for ideas here guys... Do these symptoms scream tank fuel pump? Should I hear both pumps cycle on with a KOEO on-demand test? Will the truck run on level ground at idle and highway speeds with just the HP pump running?
I'm terribly frustrated at this point and maybe missing something easy... Any thoughts are appreciated.
Dave
It has been a long while since my V8 conversion was completed (with lots of help from guys on this forum) and over the last week I've had some pretty knarly issues since returning from deployment a month ago.
1) cold start, truck idles fine closed loop but once at temp, see note 2.
2) hot start, truck idles rough, smells rich, "barbally" exhaust note, surging/hunting engine speed.
3) drives rough... Poor shifts, surges at idle, hesitation on acceleration, overall loss of power, infrequent stalling, bucking on deceleration.
4) slightest grade and the thing is gutless... Throttle wide open and its putting along. All symptoms can be induced by going up any hill.
I pulled codes and got a series of emissions related DTCs but I always have those. I got a bank 1 lean code (0171) and a HEGO code for bank one... I did not get 0174 (lean bank 2) or a code for that bank's O2 sensor.
I run only upstream O2 sensors and in an attempt to force the ECU to run closed-loop after coming to temp in hopes of narrowing down the issue, I disconnected both sensors but all the issues persist.
I start assessing the usual suspects... Vacuum leak, TPS, PCV Valve, MAF, DPFE, EGR, etc... Long story short - all of its good. I threw on new O2 sensors as I had them sitting around. Ignition and CPS are good. I pulled the upper intake off to check gaskets and to replace vacuum hoses and everything looked good. Lower intake gaskets are new and certainly aren't leaking so grossly that these issues are resulting.
On to fuel... Replaced regulator and filter and the Fuel Pump and EEC relay click with KOEO. I can hear the HP pump on the frame rail whirring but nothing from the lift pump in the tank. Would the truck run without the lift pump running? I believe both pumps get VDC from the same relay order so if one has it the other should... Barring a cut or grounded power wire.
I'm looking for ideas here guys... Do these symptoms scream tank fuel pump? Should I hear both pumps cycle on with a KOEO on-demand test? Will the truck run on level ground at idle and highway speeds with just the HP pump running?
I'm terribly frustrated at this point and maybe missing something easy... Any thoughts are appreciated.
Dave
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