5.3 4L60 swap into a 1962 c10 first drive...

[suburban99]

This truck sat since at least 2002...I towed it out of a field and loaded it on my trailer. Installed a 5.3 and 4l60e from a 2000 Sierra. First drive yesterday. Wow good power. Ran good for the first 20 minutes then hesitated...then stalled. Started back up right away and was fine for 2-3 miles then hesitated again. (No power) turned off and restarted and was fine for a short time again...got home and checked codes, #1 bank o2 sensor...no other codes. Any ideas other than the o2 sensor?

[mongocanfly]

Fuel pressure/delivery? Maybe

[ls1nova71]

Check your fuel pressure. My bet is you've sucked up some crap out of the tank and are plugging up either the pump pr filter. My truck sat a long time before I got it and I went through about a dozen filters in the Q-jet before it cleared up.

[solidaxel]

Originally Posted by mongocanfly

Fuel pressure/delivery? Maybe

x x 3

[suburban99]

Fuel pressure shows good at 60 PSI...(under hood gauge can't tell when driving)
Tank was removed and is clean (couldn't believe how clean it was).
All fuel fittings to the intake are new...

EGR is removed, rear O2's programmed out when VATS was removed.
Only OBD code is bank 1 O2 sensor...
Funny thing is when I shut it off and restarted I did a huge burn out...no lack of power after restart.

[LeesTruk]

Does your scan tool just read codes, or can you also read live data? If you have a live data stream, check what the bank 1 O2 is doing. See if the O2 voltage is "flat lined", meaning the voltages aren't toggling up/down quickly, or just reading a low voltage only (lean signal/rich command). Bad O2's will cause the engine to severely "load up" and cause a stumble/stall situation. Because you have no cat., you don't get the strong rotten egg smell associated with an over rich condition

[BR3W CITY]

When it hesitates and throws the code, try uplugging the maf and see if anything changes soon after.

[suburban99]

Can I use the downstream sensors in the upstream position? I have 2 downstream that were on the truck...I know the plug is different, just trying to save some cash..

[BR3W CITY]

I don't believe so. The downstream sensors don't have a heater circuit, and they are a narrow band sensor.

The upstreams aren't a "wideband" like we consider in the aftermarket, but it is a sort of wideband sensor. The heater circuit is what helps remove condensation from the sensor head.

[suburban99]

Ok, back at this again. Scan tool showed bank 1 position 1 o2 sensor not working. Replaced with a new one. Also changed the plugs as they were bad. Starts, runs drives good when cold. As soon as it gets warm 190 or so I now develop a stumble and it will not take WOT... it does cruise on the freeway at 70 but if you get on it will stumble. Rechecked codes and now have none. (this can be good or bad)...When cold it will take WOT and roast the tires. It almost acts like it has a vacuum leak? Any ideas...thanks

[XwalkerX]

so basically as soon as it goes into closed loop you are running into problems?

I would say vacuum leak or MAP sensor since that's primarily where the computer will gauge its fueling. secondly I would check/clean the MAF and throttle body just to be safe.

[suburban99]

Originally Posted by XwalkerX

so basically as soon as it goes into closed loop you are running into problems?

I would say vacuum leak or MAP sensor since that's primarily where the computer will gauge its fueling. secondly I would check/clean the MAF and throttle body just to be safe.

Seems like. Intake is clean, I will clean the MAF tonight...I used the EGR plate to block the hole in the intake where the EGR was located and I am wondering if it is leaking...also blocked the Power booster port on the back of the intake with the appropriate plug as I have manual brakes for now. I wonder if I missed a vacuum port?

[suburban99]

More info:
MAP was very dirty, I cleaned it and it appears to work.
MAF cleaned.
Repaired EGR block off plate.

Unfortunately still has no power when warm.
Here's some info from my Bosch scanner live data:
No codes present
Fuel sys 1 closed
Fuel sys 2 closed
Coolant temp 198
IAT 73
Idle 586
MAP 10(HG) at Idle and 7.4 at 2000 rpm
MAF .70 at idle and 1.70 at 2000 rpm
MIL off

I don't know what fuel sys 1 and fuel sys 2 means .
(in fact I did not know my scanner did live data till I read the book.. )
Any help appreciated, I am stumped..

[solidaxel]

Interesting !
I keep getting a code Lean bank 1&2 but the light goes out and the codes disappear!

[suburban99]

Cleaning the MAP seems to have worked! Love the power, got a 2nd gear chirp on the way to work this morning. I sprayed some sensor cleaned in the MAP after I removed visible crud and I guess it loosened up over night...! thanks for the help.

[foamypirate]

Originally Posted by suburban99

Cleaning the MAP seems to have worked! Love the power, got a 2nd gear chirp on the way to work this morning. I sprayed some sensor cleaned in the MAP after I removed visible crud and I guess it loosened up over night...! thanks for the help.

Glad you figured it out. Noticed in the info you posted above that the vacuum reading was really low (10hg), so that makes sense!

[suburban99]

I bet that's while the previous owner sold me the whole sierra for $1000.00...I sold the remaining pieces for more than that... I drove it around the block and backed it up ran ok in open loop ...sold (there was 2 other guys in the driveway waiting). snooze you loose.

[XwalkerX]

good to hear we figured it out!

[solidaxel]

How or what did you use to clean the MAP?

[suburban99]

Originally Posted by solidaxel

How or what did you use to clean the MAP?

I used CRC MAF and sensor cleaner...it had a wad of carbon on the end...
However on the way home from work today it was acting up again...I recleaned it tonight and we will see tomorrow. i may end up replacing it...ran good this afternoon when I picked up some steel for another project..just started on my way home.

[suburban99]

Ok still trying to get this figured out. Stopped at the auto parts store and bought a new MAP sensor. Installed in the parking lot and started to drive home. Temp was 190 so I assume it was in closed loop...Ran good for about 3-4 miles then started stumbling again with new MAP...Got home, checked the codes and none were present. This is frustrating. It ran excellent last week for a couple of days...Any ideas? Thanks

[mongocanfly]

Still sounds like a fuel issue....maybe injectors? Filter? Regulator?pump?maybe..

[suburban99]

Originally Posted by mongocanfly

Still sounds like a fuel issue....maybe injectors? Filter? Regulator?pump?maybe..

Could be injectors...fuel pump (walbro), filter, lines all new..tank was spotless.

But why would it run so good when cold...? I can drive it 3-4 miles in the morning and it has good power...

[izzy_Britton]

I am thinking pump fatigue. I had a car moons ago that would run great until i got to town. after it warmed up it would lose power and eventually die. I could wait 5 minutes and fire it up and go again for a mile or a few and it would again lose power and die. wait, drive, die, wait, drive, die. turned out to be the pump, fuel pressure was good on start up and would slowly fail and the completely quit. swapped out the pump and drove it til the trans broke.

i dunno how well these Walbro pumps work, but i noticed on another forum a guy doing an ls swap went thru something like 9 of em before he got one that actually produced the advertised fuel pressure.

MAYBE?

-Izzy

[faribran]

Any updates? Just curious.