Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
HelloCustomer are you using the procedure from any of the information systems? Also what was the original symptoms that lead to this issue?
Your JA Expert,
Jack see if this procedure helps or is any different from the one you have been using. Let me know.
Here is the troubleshooting tree for the P1345, You may have a faulty cam or crank sensor that is causing your dilemma. See where this leads you. Remember if the crank sensor is not proper, the cam synch will not be correct, and vice versa.
How about this and look at the next one too. I also found a revised procedure listed as a TSB. Look at this. Also I'm sending you another TSB on my next post. See if they help.
Here is another.
Wow, you found your issue. It shouldn't be more than a couple of degrees. 10 degrees is huge. This truck may have jumped time and the computer is trying to do everything it can to keep it running. A compression test may back you up on that one. 10 degrees if very large and I think you are there. How many miles?
Below is what I was about to send before you posted.
I've been looking on IATN and I have 2 suggestions based on what I saw, One is valve adjustment. Some overtightened valves. The second is a faulty distributor. Several posts indicated even though everything looked ok, the distributor replacement was the fix.
When graphed, here is a sample of what the crank sensor looks like. The second picture is what it looks like if the cam and crank were graphed and at the same time and everything was Ok.
The Vantage was a diagnostic, graphing volt meter that had component testing. It's incorporated into the Modis, but not the Solus. I just check the Solus' capabilities and the Solus Pro can graph data, it's not a lab scope, but you can get graphical representations of the data. You can show the crank and cam signals at the same time by choosing their PIDs from the data list and can see if you have sync. It's obvious that something was done wrong when this motor was assembled and now it's time to find out what.
Well you have a fuel pressure issue, fuel pressure should never go down, it should remain or go up when load is introduced. 50 psi is way below spec for either of the two systems. Look at these specs. If fuel pressure is too low it will compromise the engines ability to run, since these injector tappets release under pressure. If pressure is too low, fuel will not be released into the cylinder.
Yes those numbers sound right. The way that injector system works, is fuel pressure builds in the tappets that lead to the intake. When the pressure builds to a certain point, that fuel is released, strickly by pressure, not electrically. If you don't have adequate fuel to fire off the engine, the engine may kick back. If you only have 50 psi, it would definately correct the fuel pump issue, get fuel pressure up to 60 or so and see how the truck runs. The fuel pressure is definately too low, so replacing the fuel pump will not have been in vain. I think your misfire is going to be gone, after restoring fuel pressure to the proper amount, and that would explain having the problem before and after the work.
With those results, install a new fuel pressure regulator and fuel pump. You should be perfect after that
Can you look at data and see what timing advance is doing while this occurs. Does the vehicle show knocking, maybe when the engine was done, the knock sensors were overtorqued and the computer is not seeing knock, and as a result advancing the timing way to far. The crank and cam sensor are responsible. the cam sensor is in the distributor. The computer adjusts the timing based on their data.
Is the truck in closed loop? What is your long term and short term fuel trim? Could it be possible the EGR is playing a role. Maybe staying open when restarting?
Is that what you are talking about?