crank no start after rebuilding/replacing the engine?

2003 CHEVROLET AVALANCHE
1 MILES • 5.3L • V8 • 2WD • AUTOMATIC
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
My friend and I are having a problem with a crank no start after rebuilding/replacing his engine. Tested fuel pressure and had 10psi so replaced the pump and was back to 50 with the key on still no start. I tested for spark at the plug wire, and it had spark. All grounds are in the correct spots and tested good with a circuit tester. I hooked a scan tool to it, and we got it to run for about 10 seconds and I checked for engine codes there was nothing, I then did a complete system check to find a p1626 in the PCM and a B2961 in the BCM. From there I assumed the p1626 was keeping the car from running so I told my friend to get all the vats deleted when he went to get his tune for his cam so he did, after that all the vats, o2, evap were deleted but it still does not run. I still haven’t tested the injectors, or the injector harness .any help is appreciated.
Mar 16, 2024 at 4:27 PM
Advertisement
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
The first thing I would do is see if it runs on starting fluid, this will test the ignition performance and to see if the engine is in good shape. I would upload a short video in your response of the engine cranking so I can see what is going on and tell you if the engine is any good or not. Please go over this guide and i can help you get it running for you.

P1626 - Theft Deterrent Fuel Enable Signal Not Received: This code is often related to the vehicle's anti-theft system.

B2961 - Key In Ignition Circuit Malfunction: This code indicates that there is a problem with the circuit that detects whether the key is in the ignition.

Please go over this guide, also can I ask if the security light is flashing when cranking over?

https://www.2carpros.com/articles/car-not-running-advanced

Please go over this guide and get back to us.


Mar 17, 2024 at 4:23 AM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Can I ask if the security light is flashing when cranking over?
Mar 17, 2024 at 4:26 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
I have tried starting fluid and it still wouldn’t start. It runs when it wants to and as soon as it does it will run for 30 seconds then turn off. The security light also does not flash.
Mar 17, 2024 at 4:38 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
Tested injector harness and injectors and they were good, and engine is getting spark moving to compression test next.
Mar 17, 2024 at 3:31 PM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Yep, let's test for injector flash, also is there a chance the exhaust system is plugged up? I would put your hand over the exhaust pipe when cranking to see if anything comes out. These guides can help us:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

and

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Please go over this guide and get back to us.
Mar 18, 2024 at 3:21 AM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
anything?
May 11, 2024 at 5:39 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
I got it to run but now bank 1 injectors are not spraying fuel, there is power to the harness, I can physically hear the injectors firing, bank 1 fuel injector fuse is good, I can disconnect the entire bank 1 injector harness and nothing changes but when I unplug the other side you can hear each one misfire. I’m not sure if this has anything to do with the tune my friend got or if this is some kind of computer issue but I’m lost
May 19, 2024 at 9:15 AM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Good call, the left side of the engine is not firing, I would check the catalytic converter on that side it could be clogged. Also,, pull the spark plugs on that side to see if they are wet or dry. Thanks for the video it helps.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please go over this guide and get back to us.
May 20, 2024 at 5:27 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
This car doesn’t have any cats but it still has the o2 sensors, and yes last time we pulled them out all 8 were fuel fouled.
May 20, 2024 at 5:32 AM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Do you have any codes? You could have a shorted fuel injector causing the PCM to increase the duration of the pulse which holds the injector on to long. Please go over this guide and get back to me.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Also, plug the plugs and take a picture so I can see them please. if you want to upload s short video of the engine cranking over (not running) I can tell if the engine is in good shape or not.
May 20, 2024 at 5:46 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
There are no codes because the tuner disabled any misfire codes for the aftermarket camshaft, we were told the computer would always throw a random misfire because of the cam. We know the engine is in good shape 200psi of compression each cylinder, spark in each cylinder, just having a fuel problem. (All the plugs look like that one, I guess the last set of plugs were fouled because of the original crank/no start we found the problem to be a damaged neutral safety switch then it started right up after that.)
May 20, 2024 at 7:13 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
This is what the passenger side plugs look like.
May 20, 2024 at 7:25 AM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Okay, let's use a test light to check if the injectors on the drivers side are getting power and signal, this guide can help. Thanks for the video, pics

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Please go over this guide and get back to us.


May 21, 2024 at 1:20 AM
Avatar
JJ GARZA
  • MEMBER
  • 20 POSTS
I can hear them clicking, I’ve tested the harness with a Noid light which flashes consistently, there is no real way to back probe the injector ground without an actual probe kit, all injectors were around 11.8 ohms, both injector fuses are good, and I have no way to test spray pattern. I know the injectors are fine. I’ve already swapped them from one side to the other and they work so I’m leaning towards some PCM problem or tune.
May 21, 2024 at 1:32 AM
Avatar
STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Yep, so you have compression, the injectors are firing, and the ignition is working. I would try a rebuild PCM or try taking the tune out of the one that you are using.
May 22, 2024 at 3:37 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.