I've been battling a slow start problem for a few weeks now. I have replaced my ICP sensor and my IPR. I've been monitoring the oil in my resavoir and it stays within an inch. It comes for a few days and goes away. Its been in the slow start now for the past 3 days getting worse and worse and just now driving down the rode I noticed it smoothed out and had way more go. So I got home and shut her down wouldn't you know she fired up perfectly. Thats what it will do for a few days then return to slow start. I have code p1316 so I got a chance to do a buzz test today all injectors buzzed the same but that gave me codes p1272 and p1275 which I know are cylinder #2 and #5 high to low side open. My harness is less then a year old brand new from international after multiple problems with an aftermarket one from pennsacola diesel. This past week I had the valve cover off and messed with the connector still nice and tight not hanging to one side or the other and while I was in there did the 50 cent mod. Should I guess and go after the IDM or more towards the harness injector side of it?? I should also mention suspecting my harness I pulled the whole thing out and inspected wires and cleaned it up and noticed no frayed wires. Any help would be greatly appreciated.

 

Are you sure your batteries are up to par?

 

X2... Weak Batteries will play hell on our rigs

 

and no leadership

 

i had that prob had to replace starter

 

I replaced the batteries last fall with 2 new interstates and a new alternator in december. I thought that and hooked up the volt meter and not running I have 13.5 volts when its running I have 14.2volts. i replaced the started last summer. It spins over fast its just acting like its not getting fuel. This problem is getting the best of me. The only things I have never replaced are my PCM and my IDM. Its weird how it comes and goes.

 

Just for fun, check the voltage while cranking. You will need some help, but it will give you a better idea about what's going on. You could pull the top side harness and ohm out the injectors and see if anything is open. A new harness don't mean it's good.

 

I'll give that a try. Yea I know about the new not being good I had nothing but trouble when I used the new harness that came with my injectors. I put my original one on with 290,000 on it and it worked better and then the one from international worked awesome. I did inspect it last week wiggled every connection and everything was tight but now that I know which side it is I'll test those injectors tomorrow.

 

So I just finished ohm testing each injector at the valve cover harness. I think I left my DVOM in Maine so I had to use my dad's analog one and each injector was consistent right around 3 ohms

 

I have tried searching and can't find what I'm looking for can anyone point me in the right direction as to where I can find which pins I need to test between the IDM connector and the connector on the valve cover.

 

Here is the information on testing.

 

awesome. Thank you

 

Everyone of those tests passed so I assume its safe to say its most likely idm

 

I replaced my IDM today and it took care of my check engine light finally. The first few starts were slow but got better and better each time to where now it starts normally. I am however now getting a CEL for p1211 when over half throttle. So I stopped borrwed a scanner. The injector buzz test passed. So I monitored my icp and ipr here is what I got:
KOEO
ICP DC 14.9%
ICP V .22v
IPR DC 15%

KOER at idle
ICP DC 10.2%
ICP V .84v
IPR DC 10%
ICP 485psi

Cranking
ICP DC goes up to 37%
ICP Volts go up to 1.5v
IPR DC goes up to 38%
ICP goes up to 585psi then drops to 485psi once started.

Are these normal numbers?

 

Get a volt meter that plugs in the cig port to show your voltage (From wally world, 15.00)
It will show your:
1)Batt volts...key off.... should be 12.5
2) volts with key on and GPR on.... should be 11.5
3) volts when starting truck and GPR on.... should not Fall below 10.5 or truck will not start.
4) when truck starts the volts will be 11.5..... when GPR clicks off.... the volts will slowly rise to 14.5 (if Alt is good)


If you have a couple of dead cells in your batts, it may show 12.5 before starting and 14.2 when running..... but with a load on it created by the GPR AND Starter, the voltage may fall below 10.5 and your truck will not start due to 'low voltage'.