Hello all. New user here, although I watch your forum's and I am a bit amazed at the level of knowledge I have observed on here. My reason for getting on here today is that I have encountered an issue with my 2005 LLY Silverado crew cab 4x4. I just picked this truck up to use it to tow my car trailer with. It appears pretty well stock other than an aftermarket exhaust system. Truck has 136,000 miles. It is an automatic. It starts and runs fine, cold or hot. Once it gets a bit warmed up over 150-160 degrees, it starts a bit of a slight surging. It's pretty well constant at idle in park. Once dropped into drive, the surging seems more pronounced. What is weird to me, is when I turn the key off and stop the engine and wait about about 20 seconds and then start it back up it will run and idle just as nice and even as an engine possibly could. If you mash the throttle, it will immediately start that surging, slight loping again until the process is repeated. Has anybody on here observed a D-max doing something like this before? Please help if you can. I'd appreciate you.
2005 D-max LLY surging idle/slight lope
- Thread starter benny70hemibird
- Start date
Same thing my LLY is doing right now. I’ve replaced the fuel pressure regulator 3 times in 2 years and the surging has gone away each time but comes back. If you haven’t ice picked the injectors I would highly recommend that also! Mine just started surging after I replaced my faulty Airdog pump this week..don’t know if that’s a cause/effect situation... Sub’d to see what everyone else’s insight is.
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X2 for jeremy.
Benny's problem sounds like an FPR to me. Make sure to buy an OEM one, not a cheap Chinesium brand.
Three regulators in two years could be the result of bad fuel. Normal life of the CP3 pump is 150,000 miles. Replace the pump instead of the regulator if over that because the pump comes with a new regulator and you will be needing a pump soon. Bosch reman of course, not some eBay special. 
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Any advice for the guy that started this thread #1 , or do you also think it may be the FPR ?Three regulators in two years could be the result of bad fuel. Normal life of the CP3 pump is 150,000 miles. Replace the pump instead of the regulator if over that because the pump comes with a new regulator and you will be needing a pump soon. Bosch reman of course, not some eBay special.
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The regulator controls the pump PSI which in turn controls the RPM. When it gets worn or sticky it over shoots it's target and causes the lope. If a fuel conditioner with detergent doesn't work then replacement is next.
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