Found a few minutes today to do some more testing. Once up to operating temp, unhooked the 1 wire O2 sensor. Read a steady .75 volts, which is in range. While not accurate enough to show the fuel trims but it was in a decent, richer range. Unplugged the MAP and the truck runs great. No more bog. So I will look into that further.
1993 K1500 TBI stumbling/surging
- Thread starter BrianF
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Figure its time for an update on this old girl. I had it sitting for most of the summer but decided to get some more miles on her as she is a good beater. I pulled the EGR valve and did a wipe down but it was relatively clean in any event. I pulled the solenoid connector and wow, made a world of difference in driveability. I have the connector back in place but plugged the vacuum line from the solenoid to the EGR valve and it drives quite well now. Last fall I had pulled plugs and found that the passenger side bank was running rich as the plugs were all black, while the driver side bank was a nice tan color. Today I checked and all the plugs are a nice tan color.
I used a paperclip as a jumper to pull the codes last week and was getting code 32 for the EGR (no big deal) and 43 for the knock sensor. I was under for an oil change today and found the KS wire was hanging in the wind. Part of the insulator was worn away and the rubber plug worn as well. I taped it up, cleaned it all up and put it back in place. Runs even better. I may have to splice in a new connector.... hopefully not. I am hoping this will help bring its abysmal fuel mileage back up to the realm of normal.
I was planning to buy a fuel pressure gauge to check the system as you guys suggested but fell short after doing this fixes. The injector spray patterns are a nice cone shaped and even all the way around. I did change the fuel filter as I was unsure of the last change. As well it got a nasty dose of PEA based fuel cleaner.
The wife and I took it for a nice jaunt around the countryside and it definitely runs smoother. With the straight pipe true duals (no crossover) you could really tell when the banks were not firing right.
So it got oil today, ATF yesterday and next on the list is to check the output shaft seal/bushing, pinion seal, gear oil change and bleed the brakes.
I used a paperclip as a jumper to pull the codes last week and was getting code 32 for the EGR (no big deal) and 43 for the knock sensor. I was under for an oil change today and found the KS wire was hanging in the wind. Part of the insulator was worn away and the rubber plug worn as well. I taped it up, cleaned it all up and put it back in place. Runs even better. I may have to splice in a new connector.... hopefully not. I am hoping this will help bring its abysmal fuel mileage back up to the realm of normal.
I was planning to buy a fuel pressure gauge to check the system as you guys suggested but fell short after doing this fixes. The injector spray patterns are a nice cone shaped and even all the way around. I did change the fuel filter as I was unsure of the last change. As well it got a nasty dose of PEA based fuel cleaner.
The wife and I took it for a nice jaunt around the countryside and it definitely runs smoother. With the straight pipe true duals (no crossover) you could really tell when the banks were not firing right.
So it got oil today, ATF yesterday and next on the list is to check the output shaft seal/bushing, pinion seal, gear oil change and bleed the brakes.
Also edit that I pulled the cap and there was a decent amount of corrosion on the terminals and the usual wear on the rotor. I cleaned it up and some corrosion on the plug wires and that also helped. So I have just over 100$ into it.
Here is some pictures of the old girl. On the one picture you can see the remnants of some girl cowboy decal that left its mark. She is true to her rez roots with the mess of wire keeping the exhaust off the ground.
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