Need help with hard starting issues

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00farmcummins

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Just bought the truck its an 05 with 39,000 miles, it has a fass fuel pump 120ddp injectors twin cp3s, valve springs and studs and a 64mm turbo. Every time i go to start it up i always have to crank it two or three sometime 4 times to get it to start. I dont like cranking it more than 5 or 6 seconds. But it seems like it is loosing its prime. The fuel pressure gauge that is in it when the fass pump kicks on it reads about 10 pounds of pressure and as soon as the pump kicks off it starts dropping down. If the pump kicks on again it build pressure back. Weather the truck is cold or was just ran it always does this. Also if you get on the pedal very fast it sounds like it is about to kill it out seems like it is fueling very hard and doesent give the turbo time to spool. Any help would be great i havent really hooked up any pressure gauges yet to it because i just bought it and havent had time yet but any help steering me in the right direction would be a great help.
 
also forgot to mention that first thing right after it is started when it is cold it sounds like there is a cam in it and it lopes, but after it gets warmed up it dosent do it and it dosent really puff any white smoke or anything to
 
Use a scan tool to verify that all sensors are functioning properly and report back. Also do an injector return flow test.
 
Smarty is not what he was talking about. That only shows DTC's. not if a sensor or actuator is functioning within or out of its limits. You need a scan tool that shows a live data stream such as a modis or similar to see what the sensor are reading and what the actuators are doing.

Injector return flow test requires you measure the return volume of fuel in a container while running/cranking engine for X amount of time and measuring the volume.
 
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Gibson said:
Smarty is not what he was talking about. That only shows DTC's. not if a sensor or actuator is functioning within or out of its limits. You need a scan tool that shows a live data stream such as a modis or similar to see what the sensor are reading and what the actuators are doing.

Injector return flow test requires you measure the return volume of fuel in a container while running/cranking engine for X amount of time and measuring the volume.
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Which return do you use? The one from the back of the head? Where's the best place to pull it off to put it in a measuring cup or something? What is a good measurement over what amount if time? I don't want to waste money at the dealer for this.
 
dixon700 said:
Which return do you use? The one from the back of the head? Where's the best place to pull it off to put it in a measuring cup or something? What is a good measurement over what amount if time? I don't want to waste money at the dealer for this.
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Yes back of head. Just unhook the line at the fuel filter from back of head. And measure. I believe it's 30ml per injector for 30 seconds of cranking. Dont be afraid to crank on it for 30-45seconds. It can handle it. Also you can disconnect line from cp3 to rail and measure amount. I belive its 84ml for 30 seconds of cranking.

The injector return rate isn't the best way to test with injectors in truck. Because one could be way out of spec and rest be under spec and the amount measured be within limits. Best way to test is to remove injectors and take to injection shop to flow tested.


Don't take it to the dealer.
 
I believe it would be a good way to indicate a bad inj. So you don't waste time pulling then out and sending them when there is nothing wrong.
 
My big issue is that ever since I loaded up 2.2.7 scary Larry. When I start my truck it doesn't idle smooth for the first few seconds when the oil psi is working its way up. There also is more white smoke on cold start up then before. It's been in the teens and lower lately. My truck never did this until I loaded up 2.2.7. I just want to make sure I don't have any bad injectors. They are 75% over exergys that were balanced to less than 1% that now have about 5k miles on them. Cruising on I 80 my rail Is steady right at 20k. I floor it it drops down to around 17k and doesn't raise higher than that until around 3k rpms when rail shoots to 22.5k. It goes no higher. My lift pump psi at the cp3 at idle is about 24psi and under wot it drops to around 14psi. I've been told to check the torque on my new connector tubes and to check my rail prv for leakage, I just haven't had time. I'm going to try switching tunes again to see if it stops this weird start that it never did anything quite like that, even when I had bad injectors that all failed exergys testing.
 
IMAG0235.jpg

Here's my balance sheet.
 
LReiff said:
Not enough return? That's a new one!
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I guess I should have said 5 injectors could be at the lower end of the spec and one could be over the spec. Therefore you couldn't actually tell that one was returning more that supposed to if all the other 5 were in tip top shape.
 
Changed tune to 2.3pl starts normally cold now. Ran it on performance on my way out to lodi for economy. Ran fine.
 
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