corerftech
Well-Known Member
Good morning folks.
Frankentruck was driven 525 miles yesterday on a road trip.
I recently replaced a bad o2 sensor causing a very lean condition.
When test driven air temp was 50-60 deg, yesterday the air temp was 15.
A big dif in performance, it was very lean until the sun rose and air temps hit about 28 or higher, then it ran substantially better but boy was it still lean.
A couple of things that were noteworthy:
I started the truck at 15 degrees and just about evey light on the dash did something, inlcuding Rear AnitLock brake light lit.
Voltmeter was at 10 volts.
Heater FAN was on but would not activate to defrost my windows.
It ran for about 3 minutes, maybe 4 and then I decided Id better test to see if it would restart.
Restart was rough, it was mad.
Second crank it lit up like it normally does, but then all lights were normal, fan ran, voltmeter was at 14 or so.
It was really pissed about running, as lean as it was. The 18-2k range was just crap.
I decided to drive it past Nashville from Memphis and go for it.
As I drove I pondered the electrical issue, decided that absolutely there is a ground problem remaining on the truck. The TACH will bounce at times, no other electrical signs, just a bounce, intermittent. The FAN gave me a clue as to the ground point that may be suspect. I intend to ground the ECU with a new wire all the way back to battery if not already completed. Ill then ensure the cab ground is replaced back to the battery.
As for the title of the thread, LEAN...... is it possible that the ECU (as seen from the 10v gauge reading likely due to high resisance ground) struggling to fire the injectors....??? If the ECU has ground switch for the injectors, is it floating or is it a common ground reference?? If the transsistor is sinking current to a floating groudn then the ground is not associated with fueling issues. If the sink is to common ground then "potentially" the injector is only opening as far as the voltage allows and maybe the pulse waveform is not true, due to the ground resistance??
The only other two items suspect are the fuel pump and the injectors themselves. I will restate the fuel rails do leak down (new regulator installed) quickly and so either could have issue. But as I have also considered that situation, if injectors are leaking fuel after shutdown, then an immediate restart should have presented enough fuel to prevent a lean POP on ignition. There should be substantial fuel in all 4 jugs and the spray should give me a clean start.
If its the fuel pump, what shoudl be the pressure at the OUTLET of the fueul filter??? Ill pull the outlet and pressure test there. I recall somethign in the mid to high 40's but not 65 like the newer pumps.... but I may be wrong.
Any thoughts?? It was a gread road test on a beautiful cold day. truck ran great. Aside from lack of pwoer and lean, on 93 octane to Woodbury, TN (all uphill grades from Memphis there) 17.3 mpg and mostly in 4th gear at 65-70 to maintain stable running. On way back I got 22.2 on 89 and droive from Woodbury to Savannah which again is mostly grades. The ECU had been reset for the fault codes and not driven much..... 22 mpg on 60% up grades (total of miles is 60%) and on country roads unliek the trip in on Interstate.... I was pretty happy.
BTW: whne air temps hit 38 degrees the truck ran very well w/o hesitation but indeed was short of power.
Last note: The INtake manifold coolant line is capped off. The metal tube was flopping around without a home (BUBBA the B-hole fixed it). I removed the tube and capped the manifold off. I will take from the above behavior that the preheat line is pretty important to maintain and have intact for the 2.3l engine to behave well. It doesnt fix lean but it sure would help with best use of fuel that is present.... seems like this enghine is cold blodded and it needs manifold heat to run best..
Aslo any thoughts on the above.
Mike
Frankentruck was driven 525 miles yesterday on a road trip.
I recently replaced a bad o2 sensor causing a very lean condition.
When test driven air temp was 50-60 deg, yesterday the air temp was 15.
A big dif in performance, it was very lean until the sun rose and air temps hit about 28 or higher, then it ran substantially better but boy was it still lean.
A couple of things that were noteworthy:
I started the truck at 15 degrees and just about evey light on the dash did something, inlcuding Rear AnitLock brake light lit.
Voltmeter was at 10 volts.
Heater FAN was on but would not activate to defrost my windows.
It ran for about 3 minutes, maybe 4 and then I decided Id better test to see if it would restart.
Restart was rough, it was mad.
Second crank it lit up like it normally does, but then all lights were normal, fan ran, voltmeter was at 14 or so.
It was really pissed about running, as lean as it was. The 18-2k range was just crap.
I decided to drive it past Nashville from Memphis and go for it.
As I drove I pondered the electrical issue, decided that absolutely there is a ground problem remaining on the truck. The TACH will bounce at times, no other electrical signs, just a bounce, intermittent. The FAN gave me a clue as to the ground point that may be suspect. I intend to ground the ECU with a new wire all the way back to battery if not already completed. Ill then ensure the cab ground is replaced back to the battery.
As for the title of the thread, LEAN...... is it possible that the ECU (as seen from the 10v gauge reading likely due to high resisance ground) struggling to fire the injectors....??? If the ECU has ground switch for the injectors, is it floating or is it a common ground reference?? If the transsistor is sinking current to a floating groudn then the ground is not associated with fueling issues. If the sink is to common ground then "potentially" the injector is only opening as far as the voltage allows and maybe the pulse waveform is not true, due to the ground resistance??
The only other two items suspect are the fuel pump and the injectors themselves. I will restate the fuel rails do leak down (new regulator installed) quickly and so either could have issue. But as I have also considered that situation, if injectors are leaking fuel after shutdown, then an immediate restart should have presented enough fuel to prevent a lean POP on ignition. There should be substantial fuel in all 4 jugs and the spray should give me a clean start.
If its the fuel pump, what shoudl be the pressure at the OUTLET of the fueul filter??? Ill pull the outlet and pressure test there. I recall somethign in the mid to high 40's but not 65 like the newer pumps.... but I may be wrong.
Any thoughts?? It was a gread road test on a beautiful cold day. truck ran great. Aside from lack of pwoer and lean, on 93 octane to Woodbury, TN (all uphill grades from Memphis there) 17.3 mpg and mostly in 4th gear at 65-70 to maintain stable running. On way back I got 22.2 on 89 and droive from Woodbury to Savannah which again is mostly grades. The ECU had been reset for the fault codes and not driven much..... 22 mpg on 60% up grades (total of miles is 60%) and on country roads unliek the trip in on Interstate.... I was pretty happy.
BTW: whne air temps hit 38 degrees the truck ran very well w/o hesitation but indeed was short of power.
Last note: The INtake manifold coolant line is capped off. The metal tube was flopping around without a home (BUBBA the B-hole fixed it). I removed the tube and capped the manifold off. I will take from the above behavior that the preheat line is pretty important to maintain and have intact for the 2.3l engine to behave well. It doesnt fix lean but it sure would help with best use of fuel that is present.... seems like this enghine is cold blodded and it needs manifold heat to run best..
Aslo any thoughts on the above.
Mike