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hygear · 08-06-2021, 06:49 PM

2003 8.1 GM, 2003 Brave 30W
Engine is running fine. Shut it down for a short period like to refuel. When restarted it sputters like it’s having trouble turning over. When it starts it’s barely running, 400 RPM. Pressing on accelerator only brings it to 2000 RPM. Putting its gear it only creeps. No power. Shutting it down and allowing the engine to cool off. Has resulted in the engine running correctly. Shop originally blamed it on the throttle body. Replacing it. That did not fix the issue. Has anyone else have this issue? We are in the middle of trying to sell this MH. Trying to find out the problem.

Oemtech · 08-06-2021, 07:06 PM

Check the fuel pressure to start with.

Steve43 · 08-06-2021, 07:34 PM

I had the same problem when I first bought my 2004 HR in 2018. Would go to a gas station for fill up and when started, wouldn't even creep - not enough power. Thought it was a certain gas station that had to be haunted. Wouldn't happen elsewhere and only on fill up. Got it to finally work by restarting many, many times and boom, it all of a sudden worked. Replaced the throttle body, that didn't fix. Finally replaced the whole electronic throttle assembly - both driver and engine. That fixed it. Somewhere north of $500 to fix. I can dig out the work order to find the exact parts replaced if you need that info. Has not caused a problem since then.

hygear · 08-06-2021, 08:45 PM

Steve43, I’d really appreciate if you could a list of parts replaced and the work order. I’ll need this to give options to my shop. Your description of the symptoms sound identical.

Full-Timers · 08-06-2021, 09:26 PM

Check for codes. Might be something pending that isn't turning on the Check engine light.

hygear · 08-06-2021, 09:30 PM

When it went in the shop for the first time the code called for the throttle body replacement. That’s what was done. $459 later problem is still there. But I’m sure my shop will run the codes again.

SmilingSam · 08-07-2021, 12:49 AM

First step is to clean and re-seat all ECM and TCM, throttle elec connections, should never hurt to do this and is just a simple time consuming, little skill first step.

Also, do we assume they actually hooked up a diagnostic tool to get the 'replace TPS' suggestion or was there just a code, a real diagnostic tool would ALLOW to test the TPS LIVE, move throttle and see the values change OR not - if NO change then first step is connections as TPS is elec sensor for ECM/TCM !!

GL!

Mudfrog · 08-07-2021, 10:20 AM

Our 2003 Workhorse started giving me the "reduced engine power" notice upon start up after the engine was hot. The starter seemed a bit weak during those times. The cranking battery was right at the 9 year old mark so I decided to go ahead and replace. Knock on wood, no problems since.

Steve43 · 08-07-2021, 04:41 PM

Quote:

Originally Posted by hygear

Steve43, I’d really appreciate if you could a list of parts replaced and the work order. I’ll need this to give options to my shop. Your description of the symptoms sound identical.

Ok - paperwork doesn't go into full detail but . . I was getting check engine light and throwing code - code P1516. (Bought a scan gauge after it happened a few times and always keep it connected). Changed the throttle body (parts 61178 and 12679526).

2nd time in they changed the throttle actuator control assy - it was part of other repairs and not broken out so I don't have part numbers. Once both were done, I have not had any additional problems.

Hope this helps . . I know others are trying to be helpful but for me . . it was not heat related - it could happen if I took the coach out of storage and drove 2 miles to the gas station or I just finished an 8 hour day of driving. I kept thinking maybe it was something I was doing by filling it up full (waiting for the gas pump to automatically shut off) but it rarely happened at other gas stations. Was it the gas at this particular station? It always happened as I just started up after fueling so that couldn't be it. Check engine light would eventually go away until it happened again.

yeloduster · 08-08-2021, 08:29 AM

The OP's symptoms match vapor lock. These engines should not vapor lock because they have a fuel return line from the fuel rail to the fuel tank. If the return system is not functioning you might get these symptoms.

hygear · 08-10-2021, 09:17 PM

Slightly new development. Ran it Saturday night, engine ran fine. Next morning a couple coming over to look at it since it’s for sale. Engine was acting up. Shut it down and pulled the negative cable. Put it back together and ran fine. Was able to take it for a test drive. Afterwards started up and ran fine when I brought it back to the shop. Turned off the engine and restarted. No power, no acceleration but something new. No dashboard. No tach, lights, fuel Guage. Nothing. Shut it down then restart. Dash came back. Still no power. But now LED screen read “reduce engine power”. Leading me to believe that the controller was reducing the power not a problem with fuel pressure or the throttle body/actuator. Mechanic has it now.

ktoutoor · 08-12-2021, 12:25 AM

I just love intermittent problems.. you may have a poor ground or poor fuse connection follow me on how I fixed a poor ground problem on this workhorse W24, and do the same on yours be sure to check the main ground cable off the battery not "at" the battery but where it bolts to the frame remove sand down to shiny metal then reinstall.