RPM will not go above 2,000

[fire22dirver]

Today on my home from work, as I was climbing a pretty good hill and trying to pass another car, my truck downshifted and all was good. But, then as I started cruising again my RPMs would not go above 2,000. I pulled over shut the truck off, let it set a couple of minutes and started a again, and all was good. Until, I started from a stop with full throttle and after that the RPMs would not go above 2,000. It did this even when in park, like there is a rev limiter at 2,000. Looks like my next stop is the dealer service shop. Just wondering if anyone had any ideas of what could be up with my truck???

2005 stock motor only 16000 miles.

Thanks for your ideas...

[number1motorhead]

Could be a plugged fuel filter. They have a service interval of 15,000 miles. Not saying this is definatly the problem, but if it is, the dealer won't cover it as it is a maintanance issue. Check the air filter too.

[mark45678]

I would put a new fuel filter on it NOW before your dealer get there hands on it..... Many times this is all you need to fix problems like thsi. The ECM looks at the fuel system presures pre pump , post pump , high pressure If any one of these is out of spec it limits the motor to 2000 rpm.

[MikeC]

A friend of mine bought an '05 at the same time I did.

Same symptoms and we changed the fuel filter as mentioned for you.

The filter did not fix it and when he took it in, it was victim of a known "injector pin" problem, which was covered under warranty.

Mike

[number1motorhead]

Yes, injector pin connection problems can cause this, but they almost always cause a rough running engine condition along with it. Good point, I forgot about that.

[fire22dirver]

Drove to work this AM without a problem, but I did baby her (what fun is that) seems that as long as a stay out of the peddle it runs fine. I am going the change the fuel filter, maybe that will solve my problems.
Thanks for your ideas, Love the support this site gives me.

[medic198]

Remove and clean with startng fluid, your mass air sensor. Had the same problem I an add on air filter and the oil from it caused it to fall flat on it's face out of the hole. Nothing more than 2000 RPM. Same yourself some time and maybe money....clean it. I just spryed the sensor heavy...and let it dry, reinstall and fixed the problem

[Kennedy]

There will be a DTC set in History. It is likely P1093. Changing the fuel filter is the first step. Adding a good lift supply pump setup is next step:

http://www.kennedydiesel.com/images/pumpfilter_dmax.gif


Here's how you can test your filter restriction:


http://www.kennedydiesel.com/images/Dmax-fuel-filter-rest1.gif

[Jamie Kennedy]

Hi, this is my first time in the forum. I had 05 GMC in the shop, after replacing the relief vavle and complete rail; still no fix....replaced fuel injection pump to fix problem. Seems ECM detects flunctuations in pressure causing code P1093 to set giving the low power feedback and evidently the fuel is returned to the tank through the relief vavle???? cheers, Jamie.

[Jamie Kennedy]

HI forum, looks like I wasn't correct on this one. The fuel injection pump apparently didn't repair the issue. Code p1093 re-appeared causing the rev to be limited to 2000 rpm's. I repaired a kinked flex line on the chassis and changed the fuel filter again for good luck--still no fix. It takes approx. 1.5 hrs to duplicate.?????any suggestions. JK>

[Jamie Kennedy]

Hi, still wondering about Your thoughts. Thx. JK

[Kennedy]

Add lift supply pumps. The pump needs some help getting fuel from the tank. My twin pumps are what I'd recommend as some that go single just don't see quite enough "help" and still have issues.

With lift pumps you'll get longer filter service life and better filtration as an added bonus.

I get this call all the time especially from those who use performance fueling mods and it pretty much always cures them...

[Jamie Kennedy]

I will pass on Your recommendations, certainly makes sense with the condition that's present. I am in Canada, so is the product available here as well. JK.

[Kennedy]

We ship to Canada. I'm also working with a potential dealer in Canada.

[JohnC]

I will pass on Your recommendations,

Isn't English just the greatest language? ;)

[rob from bc canada]

No kidding - maybe that explains why we can never pin down our infamous politicians!!

Whatever they say can always be re-interpreted to mean what they currently think they would like to have said!! :D

[Jamie Kennedy]

thx guys for the input, always great to have honest opinions right??????

[04silverbirch]

Check your fuel rail relief valve. If you were demanding alot of fuel when it occurred, more than likely your fuel rail relief valve is week and dumped the fuel when pressure was high. To test, go out and drive it hard, if it goes into limp mode when you are demanding alot of fuel (fuel pressure is high), fuel rail valve is week and needs to be replaced P1093 is code if I remember right..There is a GM bulletin on this.

[Jamie Kennedy]

Thx. , however I changed the relief vavle first then ended up changing the complete rail which was recommended by GM due to possible stress in the rail when removing the OEM vavle. ??????

[Jamie Kennedy]

Just to fill everyone in here, the vehicle is finally repaired by replacing #1 and # 7 injectors due to high fuel return flow @ 63 mm3 rather than @ 30 mm[3]. The pressure sensor did it's job in sensing the fluctuation in pressure and as a result code 1093 was set, the ECM set in limp mode and limited RPM's at 2000. Jamie.:)