justbinfishin
Newbie
I've been working my way through my 1988 K1500 with a 4.3 tbi and NV3500 manual transmission. I picked it up for cheap and it's been a fun project, but I'm in need of a fresh perspective. The truck has 40k on a the engine/160 on the body (Previous Owner had a FPR burst and wash down all the cylinders). The replacement was done in the late 90s, so it's gotten very few miles per year.
The only code I have is 32, because the EGR ports are completely sealed with hard carbon. I plan to clean them out when I do the lower intake manifold gaskets preventatively this winter.
I immediately rebuilt the TB to address weeping seals and replaced the FPR spring (was in 5-6 pieces). I replaced the injectors while doing so because the spray patterns weren't great. For brevity, every replacement part has been ACDELCO Pro/Gold/Whatever they called them at the time. I also replaced the IAC valve at this time, because the body of the original was cracked from being removed with channel locks at some point. I followed the IAC calibration methods I found on the web. The idle seems inconsistent and either a bit high or a bit low. I have searched extensively for vacuum leaks with propane and a carb cleaner and found nothing, but I replaced the PCV hose and EGR solenoid hose because the fittings looked suspect.
Shortly after the TB rebuild, I had a hard start when hot condition that turned out to be the pickup coil (insulation was degraded and corroded bare wires were visible). I replaced the whole distributor/cap/rotor, as well as wires/plugs because the old ones were of unknown vintage. I set the timing to 0 with the timing advance plug disconnected. I didn't like that the PO had autozone O2 and ECT sensors in there, so I replaced them. While the O2 sensor was out I checked exhaust back pressure, and it's flowing freely.
Once it was running smoothly, I was a bit surprised with how gutless it is on the highway. I wasn't expecting vortec performance, but my friend had one of these trucks with a 700r4 in college and it screamed by comparison. My 92 4.0 ranger with a thousand pounds of firewood in the bed was considerably peppier. On steeper highway hills I'm routinely having to hit 3rd and losing steam at 55mph.
A few weeks ago, it developed a miss/hesitation when cruising that would smooth out when accelerating. I checked my FP while driving with the gauge taped to my windshield, and the pressure was a steady 13 psi at all times, even with the accelerator floored getting up to speed. I traced that particular issue to the TPS, which was sitting at 0.7 volts at idle, and 4.0 at WOT, and the curve was not smooth on my analog voltmeter. I replaced it, and the new unit is 0.66-4.54v. The idle reading seems high to me, but the bolt holes leave no room to twist the sensor like you could on my old 6.2 diesel trucks.
I spent some time cleaning up the grounds under the hood yesterday because they were looking slightly crunchy. No improvement.
I checked the voltage supplied to each sensor, and noticed that the ECT plug is only supplying 4.1 volts from the computer. Should it be 5v?
I ordered a usb to obd1 plug so I can stream data on my laptop, but despite all my reading on these systems, I hope I'm just missing something obvious.
Thank you all.
The only code I have is 32, because the EGR ports are completely sealed with hard carbon. I plan to clean them out when I do the lower intake manifold gaskets preventatively this winter.
I immediately rebuilt the TB to address weeping seals and replaced the FPR spring (was in 5-6 pieces). I replaced the injectors while doing so because the spray patterns weren't great. For brevity, every replacement part has been ACDELCO Pro/Gold/Whatever they called them at the time. I also replaced the IAC valve at this time, because the body of the original was cracked from being removed with channel locks at some point. I followed the IAC calibration methods I found on the web. The idle seems inconsistent and either a bit high or a bit low. I have searched extensively for vacuum leaks with propane and a carb cleaner and found nothing, but I replaced the PCV hose and EGR solenoid hose because the fittings looked suspect.
Shortly after the TB rebuild, I had a hard start when hot condition that turned out to be the pickup coil (insulation was degraded and corroded bare wires were visible). I replaced the whole distributor/cap/rotor, as well as wires/plugs because the old ones were of unknown vintage. I set the timing to 0 with the timing advance plug disconnected. I didn't like that the PO had autozone O2 and ECT sensors in there, so I replaced them. While the O2 sensor was out I checked exhaust back pressure, and it's flowing freely.
Once it was running smoothly, I was a bit surprised with how gutless it is on the highway. I wasn't expecting vortec performance, but my friend had one of these trucks with a 700r4 in college and it screamed by comparison. My 92 4.0 ranger with a thousand pounds of firewood in the bed was considerably peppier. On steeper highway hills I'm routinely having to hit 3rd and losing steam at 55mph.
A few weeks ago, it developed a miss/hesitation when cruising that would smooth out when accelerating. I checked my FP while driving with the gauge taped to my windshield, and the pressure was a steady 13 psi at all times, even with the accelerator floored getting up to speed. I traced that particular issue to the TPS, which was sitting at 0.7 volts at idle, and 4.0 at WOT, and the curve was not smooth on my analog voltmeter. I replaced it, and the new unit is 0.66-4.54v. The idle reading seems high to me, but the bolt holes leave no room to twist the sensor like you could on my old 6.2 diesel trucks.
I spent some time cleaning up the grounds under the hood yesterday because they were looking slightly crunchy. No improvement.
I checked the voltage supplied to each sensor, and noticed that the ECT plug is only supplying 4.1 volts from the computer. Should it be 5v?
I ordered a usb to obd1 plug so I can stream data on my laptop, but despite all my reading on these systems, I hope I'm just missing something obvious.
Thank you all.
