Silverado, low fuel pressure?

General engine tech -- Drag Racing to Circle Track

Moderator: Team

user-23911

Re: Silverado, low fuel pressure?

Post by user-23911 » Sat May 12, 2018 5:50 am

A rag.

Truckedup
Guru
Guru
Posts: 1864
Joined: Mon Jan 21, 2013 2:41 pm

Re: Silverado, low fuel pressure?

Post by Truckedup » Sat May 12, 2018 11:06 am

I believe the starter needs to be pulled to get at the crank position sensor....Might be wise just to spend 35 bucks to replace it?
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire

Truckedup
Guru
Guru
Posts: 1864
Joined: Mon Jan 21, 2013 2:41 pm

Re: Silverado, low fuel pressure?

Post by Truckedup » Sat May 12, 2018 11:07 am

Truckedup wrote:
Sat May 12, 2018 11:06 am
I believe the starter needs to be pulled to get at the crank position sensor....Might be wise just to spend 35 bucks to replace it instead of cleaning?
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire

V Remian
Member
Member
Posts: 143
Joined: Sun Feb 13, 2005 11:34 am
Location: Central Massachusetts

Re: Silverado, low fuel pressure?

Post by V Remian » Sat May 12, 2018 7:13 pm

Here is my take on the crank sensor subject, take it for what it's worth. I have never seen a bad crank sensor on an LS engine. That being said...I had one truck brought to me that would seem to cut out intermittently. When I say cut out,I mean it felt like a minimum criteria lock up skip but it would do it at higher RPM and either in and out of lock-up. Watching engine data showed an intermittent loss of RPM on the scan tool when it acted up.

An independent shop had previously replaced the crank sensor so they must have seen the same thing. Upon inspection the single bolt bracket that attaches the sensor was bent slightly due to corrosion build up under the sensor mounting face. Cleaned the interface and replaced the crank sensor and all was well. I've never seen that before or since.

Truckedup
Guru
Guru
Posts: 1864
Joined: Mon Jan 21, 2013 2:41 pm

Re: Silverado, low fuel pressure?

Post by Truckedup » Tue Jul 10, 2018 4:17 pm

So....two shops can't fix it....Their scanner show the misfiring on cylinders 1 and 6, a typical thing on these engines. A crank position relearn is supposed to be the fix ..But they couldn't do even though their scanners supposedly have the capability...The misfire is not very noticeable and the scanner shows its caused by a lean fuel mixture at 2200-3000 rpm and high intake vacuum, light load...There are no leaks in the intake system and the injectors have been changed...
Going in to the local Chevy dealer tomorrow...Service guy said it's a common problem...
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire

midnightbluS10
Expert
Expert
Posts: 519
Joined: Sun Oct 20, 2013 8:41 am

Re: Silverado, low fuel pressure?

Post by midnightbluS10 » Wed Jul 11, 2018 5:55 am

9 times out if 10, when it wasn't ignition related, it was dirty fuel injectors filled with junk when I worked at the dealership a few years ago.
JC - Precision Guesswork & Expert Up Arrow Manipulation

Truckedup
Guru
Guru
Posts: 1864
Joined: Mon Jan 21, 2013 2:41 pm

Re: Silverado, low fuel pressure?

Post by Truckedup » Wed Jul 11, 2018 8:27 am

midnightbluS10 wrote:
Wed Jul 11, 2018 5:55 am
9 times out if 10, when it wasn't ignition related, it was dirty fuel injectors filled with junk when I worked at the dealership a few years ago.
The thinking here is the ECU is not controlling the injectors properly at certain rpm's and high intake vacuum. Supposedly the ignition is doing it;s job...
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire

Post Reply