Bad performance

Hello,

Sounds like it could be a timing issue to me, I would check that first before doing any parts changes. Do you know how to check that?

This guide can help

https://www.2carpros.com/articles/engine-has-low-power-output

Tom

Hi,

Well not really, the ECU will pick up a problem generally. How did the shop or whoever verify that the catalytic converter had good flow through it. It sounds like a restriction if no lights on and developing no power. The VVT failing would have other issues present It sounds like a restriction somewhere. It could also be the fuel filter clogged up. How did the problem come on, overnight or slowly with time?
Tom

Hello,

Very interesting. Which model do you have the 1500,2500, or 3500? When you have the van in park and you give it gas does it take a while to have the rpm's rise how responsive is it? Does it shoot right up or take time like when your driving? I'm trying to verify it's the motor and not the transmission or the brakes dragging. After a drive go out and feel your tire's rims to see if they are hot. Are there any engine noises, any ticks or anything like that?
Tom

Good morning,

Slight hesitation, so the rpm's do in fact go up slowly in park? I'm still not convinced we're not looking at the transmission in the wrong gear making it feel like the engine doesn't have power. If it is starting off from stop and not in first gear it would feel like it's the engine at fault. Try to put the shifter in 1 position and see if it takes off slowly. In first get the rpms to 2,500 rpm's then floor it and see if it takes off to 3,500 rpm's quicker or more normal. I've found some technical service bulletins on this condition of no power, one pertains to detergent gasoline and clocking injectors and another having to do with the catalytic converters and there is one dealing with the transmission that's seem to address what I think we are seeing. Give me a few minutes and I'll get them posted up for your review. I'd like to confirm there are no lights on the dash lit correct?
Tom

Hi Mbowtie,

There are a whole bunch of TSB's listed for this rig, to many to post but I've gone through them some do speak about no power. Is there anything else no right with any electrical things? Check all the fuses in the van just to be sure one bulletin is about shifting and it starting in the wrong gear a blown fuse is related so check them all. I'm attaching part of the one dealing with Tier One fuel detergent which I think is Shell maybe Mobil gas. At he end of this I'll put the one that is the Catalytic issue which says the ground wire for them can have a bad crimp so go through and test to see if they are grounded good, also when the shop tested them did thy check there electrical function that if fact they are sending a good data signal. There's also Calibration and relearning issues which seem a bit suspect relating to the transmission gearing. Has the rig had any servicing at all since this begun did the previous owner mention. Google these two TSB numbers and you can read them. There is mention of after market Calibration issues. Looks like the systems do need to be re-calibrated at times and needs to be done at the dealer (classic). It might not be a bad idea to call the local dealership about factory calibrations. When and why there are needed. You may get some insight too. If the CAN system and ECU aren't all on the same page our symptoms very well could arise from that and have no codes present or dash warning on.
Let me know if any of these things makes sense to you.
Tom
2carpros

GM TSB power loss
#18-NA-102 and # 07-06-04-019F
TSB
Models: 2016 and Prior GM Cars and Gasoline-Powered MST Light Duty and HD Trucks
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Technicians may encounter a concern where the catalytic converter has come apart or has set a P0420 and/or P0430.

Recommendation/Instructions
If you believe the catalytic converter has failed with no apparent reason, it is recommended to inspect for a poor crimp for the coil grounds terminal on the engine block for the bank with the concern.
Technicians should inspect the ground for possible corrosion or damage at ground terminal ring, fasteners and grounding surfaces.
If no corrosion or damage is found, tighten the ground bolt to the proper torque
Warranty Information
For wiring repairs covered under warranty, please refer to latest version of bulletin 10-00-89-005 for warranty information on wire/connector repairs.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

It has been a really long time since seeing a condition like what I suspecting on this, 1 the timing isn't correct and 2 the transmission isn't gearing correctly, but as for the first one on timing, way back in the day when all cars had timing chains we would get every once in a while a no power condition with high mileage cars the timing chains would stretch. When that would happened we would have no power and everything looked fine. This has a chain and I suppose it could be the case. A last resort check but I'm feeling like a timing issue n this but it's the computer doing it from either bad data going into the system or the system itself not calibrated or a module to module communication issue. The CAN system. Scanning that should also probably be done.
Tom

Hi,
0 to 60 mph in 14 seconds is no racer, lol. What does the engine sound like, does it sound like its working hard or is it just a slow take off but the engine sounds normal. Its hard to explain but an engine pushing through a restriction or off the wrong gear has a different type of sound. Can you upload a video of a typical take off up to 60 mph? I want to hear the shift change if possible and know what rpm's its at during that the first gear shift up. For that test don't floor it all the way just most of the way. When the gas pedal is to the ground a switch gets triggered that overrides the normal operation. I want to know the rpm's and sound without that switch triggered.
Idk if a transmission shop is needed at this time but maybe, I would call AutoZone and see if there scanner will do a CAN scan and if not ask them who in your area will and go from there. I will do more research on this Calibration thing and get back to you in a little while. If you let me know what town your in I can probably get in contact with places near there to explain what we have going on so its not a square one thing with you trying to do that. It will probably save you time and money.

Here is how you can do a can scan

https://youtu.be/InIlnsjOVFA

Tom

Hello,

It's my pleasure to be helping out, here at 2CarPros this is what we are here for. Keeping people on the road safe and sound without going broke dealing with the dealerships or shops. Yes, that surge when floored is expected. Try this test, as mentioned before when the gas pedal is pressed to the floor the last bit hits a kick down switch that wont kick down unless it's all the way. So if you are getting on the highway or a place like that press the pedal almost to the floor but not quite, you should be hearing the engine labor going about 35 maybe 40 mph. With your symptom you wont be taking off all that fast, at that moment, press the pedal all the way. Then transmission should kick down to a lower gear the engine should rev super high and you should accelerate quickly. We're seeing if one, does it kick into a lower gear and two, do the rpm's shoot straight up to a high rpm? If it kicks down but the engine doesn't have a quick rpm rise our problem is in the engine. If it doesn't kick down and the engine labors with no quick rpm rise then its a transmission issue.
Let me know,
Tom

Good Morning,

Thanks for the video.
Being a delivery van and going in and out of the rig all day, water getting in the car is probably common for you. On some vehicles, the IP to body harness connector, which carries the APP signal to the ECM/PCM, is located in the left hand kick panel area and if the kick panel is not sealed properly, water enters and causes a short in the APP circuits. Locate the IP to body harness connector, which should be located in and around the left hand kick panel area. Check to see if there is a water leak into the area.

I got the good headphone out and could hear pretty good. The second one did seem to show that the transmission is kicking down properly. How much cargo are you moving around with that, is is bulky and light or are your loads heavy?

Tom