Ok guys what would cause my truck to have a surge at idle?? When ur setting on the inside with the windows up radio off it kinda sounds like the alternator is constantly charging. Someone told me it could possibly be alternator surge so I unhook my alternator an started the truck an the sound that sounded like the alternator constantly charging was gone but the truck still seem to have a slight surge. Ive checked the voltage at the batteries while running an both were reading around 13.85 volts. So why would the alternator sound like its constantly charging and the only reason I think its constantly charging is bc u can hear the slight humm that it has. But Im mainly wondering why Im surging at idle an what will fix this. BTW vp44 has been replaced, 14-17 fuel psi from airdog, cleaned map and iat sensor, and Ive went over some other things an still no cure.

 

does it do it after the truck is up to operating temp? could be your hearing it load from the intake heater.

 

Whats up redneck!! My truck is doing the same thing and is driving me crazy!!! It started after i replaced my injectors. The truck runs great driving but as soon as I push in the clutch...it surges really bad for a few seconds then pans out. It also seems to almost surge or skip at idle. I bled th fuel system good after the injector install, airdog is pushing 14-15 psi, vp44 about 6 month ago and reset my TPS. Still same problem!!!!! If you figure the problem out PLEASE let me know and I wil do like wise!

 

It doesnt surge while its cold it only does it when its up to operating temp. Im begining to wonder if its sucking air somewhere in the fuel system/fuel lines. There is some spots on the fuel lines thats cracked preaty good an Im wondering if its allowing it to suck air in. So heres another question for yall is it prosible for the airdog to suck air from the cracks in the fuel lines an NOT leak fuel cause Ive looked an felt for fuel leaks an can find none.

 

Yeah mine surges worse when it warms up too.
I wouldn't think it would suck air on the pressure side of the airdog pump...it would leak fuel. The only place it would suck air is in the line from the tank to the airdog pump.

 

Yeah thats were the line has quite a bit of cracks in the line is from the tank to the airdog. Some how it was pinched between the frame and the bed, not sure how it got like that. Also while I had the truck running an was looking for fuel leaks I just happened to grab the fuel lines an noticed something weird. The line going to the airdog didnt really have much of a vibration to it but the lines to the injection pump and the line going back to the tank had quite a bit of vibration to from the fuel flowing in them. Is this normal or could this mean its sucking air???? This surge is really starting to **** me off

 

Sounds like air getting in your lines or trash in the pump or filter...start from the beginning of yer fueling system and trace it out changing, cleaning and tightening everything that looks suspect as you go... But as far as the alternator, could be a coil going bad but I'm not sure.. They sometimes make noise if a coil is out a bit from extensive overheating....but it would seem you would have had warning signs of extra heat under the hood...

 

Well the alternator is probably 2-3 yrs old not really sure but it looks like it caked up with oil from where the crank case breather was coming down by the fan an the fan slung it up on the alternator but I talked to a guy an he said it could possably be the voltage regulator in the alternator but Im not sure. But when I did unhook the alternator I couldnt hear the humm coming from under the hood, but when I hooked it back up the humm was back. BTW hows the best way to clean out the fuel tank? Thanks for all the replies and info guys I really appreciate it thats why I love this site.

 

If the humming is coming through in your speakers, I would agree that its the voltage regulator... but if it's outside noise, Its something else... you can probably go get the altenator tested at autozone or a local mechanic shop..... as far as an easy solution to cleaning your fuel tank, I don't have one... the only recomendation would be to test your fuel with some dip paste... check for algea and water... if it's algea the use Algea X to get rid of it... but keep a few spare fuel filters handy..cause it will probably run through after the X breaks it down..

 

Typically this "surging" you are speaking of is caused by the intake grid heaters kicking on and off during a warm-up period, which can take quite a long time. However, you guys seem to be saying that it continues and gets worse when warm, and that makes no sense as to being the grid heaters. Anyhow, just something to think about. If you want to eliminate them as a possibility, I'd say disconnect the relays for the intake grid heaters and see what happens.

Best of luck.