1962 C10 5.3L swap Maf question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

suburban99 · 09-26-2015, 08:12 PM

Got my 2000 5.3L 4L60E running...sort of. With Maf unplugged it runs at about 2000 RPM (hard to tel because no gauges or exhaust yet).
When I plug in the MAF the engine slows down to about 400RPM and almost stalls. I built my own harness so possibly I have something wired wrong?
Sure felt good when I turned the key and it started though!

aknovaman · 09-26-2015, 09:56 PM

Truck harnesses have the inlet air temp sensor built into it. Thats why they have 5 wires. With it unplugged, the pcm is seeing -40 degree temps. I don't have my software with me but the file does not have coolant temp idle speed modifier tables. It does have timing modifiers that may advance the timing and subsequently raise idle speed.

suburban99 · 09-27-2015, 12:18 AM

I don't have the coolant temp sensor hooked up. I also do not have the O2 sensors hooked up..do I need the O2 sensors to get it to run right?

BR3W CITY · 09-27-2015, 01:26 AM

With the maf unplugged it ignores 02 sensors and goes SD. When you plug the maf back in, it looks for the front 02's and when it doesn't see them, it struggles with short term fuel trims.

aknovaman · 09-27-2015, 07:45 AM

In your case lack of coolant temp, the pcm sees -40 degress and raised the idle and dumps tons of excess fuel like full choks.

suburban99 · 09-27-2015, 11:38 AM

I checked again and I have coolant sensor installed in motor...I thought there was one in the rad?

BR3W CITY · 09-27-2015, 01:36 PM

Quote:

Originally Posted by suburban99

I checked again and I have coolant sensor installed in motor...I thought there was one in the rad?

The coolant temp sensor reads the temp from the engine itself. A sensor on the radiator would only be useful to measure the actual temp drop across the radiator, which I don't think any of the GM applications use. Some vehicles had a coolant level sensor, but its not needed to run or involved in the engine control.

suburban99 · 09-27-2015, 06:24 PM

Ok got the O2 sensors hooked up but with no exhaust pipes.. they just dump right after the sensor bung. Disconnected the battery for a few minutes, reconnected and it idles...Not great but hard to tell without exhaust.

BR3W CITY · 09-27-2015, 07:06 PM

grab a 12" flared extension pipe and slap it on the exhaust collector. We do it all them time when people bring in cars for a tune w/ open headers.

09-26-2015, 08:12 PM	#1
suburban99 Registered User Join Date: May 2014 Location: Mission BC Posts: 452	1962 C10 5.3L swap Maf question Got my 2000 5.3L 4L60E running...sort of. With Maf unplugged it runs at about 2000 RPM (hard to tel because no gauges or exhaust yet). When I plug in the MAF the engine slows down to about 400RPM and almost stalls. I built my own harness so possibly I have something wired wrong? Sure felt good when I turned the key and it started though!

09-26-2015, 09:56 PM	#2
aknovaman Registered User Join Date: Aug 2013 Location: Tecumseh Posts: 355	Re: 1962 C10 5.3L swap Maf question Truck harnesses have the inlet air temp sensor built into it. Thats why they have 5 wires. With it unplugged, the pcm is seeing -40 degree temps. I don't have my software with me but the file does not have coolant temp idle speed modifier tables. It does have timing modifiers that may advance the timing and subsequently raise idle speed. __________________ Current project 1959 Willys = GEZR TRUK Geezer is a Latin compound word made up of two roots. Gee meaning Urine Stain and Zer meaning your pants are open! FMCDH GBU and GBA http://www.youtube.com/user/aknovaman/videos

09-27-2015, 12:18 AM	#3
suburban99 Registered User Join Date: May 2014 Location: Mission BC Posts: 452	Re: 1962 C10 5.3L swap Maf question I don't have the coolant temp sensor hooked up. I also do not have the O2 sensors hooked up..do I need the O2 sensors to get it to run right?

09-27-2015, 01:26 AM	#4
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: 1962 C10 5.3L swap Maf question With the maf unplugged it ignores 02 sensors and goes SD. When you plug the maf back in, it looks for the front 02's and when it doesn't see them, it struggles with short term fuel trims. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

09-27-2015, 07:45 AM	#5
aknovaman Registered User Join Date: Aug 2013 Location: Tecumseh Posts: 355	Re: 1962 C10 5.3L swap Maf question In your case lack of coolant temp, the pcm sees -40 degress and raised the idle and dumps tons of excess fuel like full choks. __________________ Current project 1959 Willys = GEZR TRUK Geezer is a Latin compound word made up of two roots. Gee meaning Urine Stain and Zer meaning your pants are open! FMCDH GBU and GBA http://www.youtube.com/user/aknovaman/videos

09-27-2015, 11:38 AM	#6
suburban99 Registered User Join Date: May 2014 Location: Mission BC Posts: 452	Re: 1962 C10 5.3L swap Maf question I checked again and I have coolant sensor installed in motor...I thought there was one in the rad?

09-27-2015, 06:24 PM	#8
suburban99 Registered User Join Date: May 2014 Location: Mission BC Posts: 452	Re: 1962 C10 5.3L swap Maf question Ok got the O2 sensors hooked up but with no exhaust pipes.. they just dump right after the sensor bung. Disconnected the battery for a few minutes, reconnected and it idles...Not great but hard to tell without exhaust.

09-27-2015, 07:06 PM	#9
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: 1962 C10 5.3L swap Maf question grab a 12" flared extension pipe and slap it on the exhaust collector. We do it all them time when people bring in cars for a tune w/ open headers. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.