Long crank when cold

RyanG · May 17, 2017

Have an 05 with odd issue. When engine is cold it has a really long crank like when the high pressure oil system was drained for repair. IPR goes to 85% and icp is slow to build. Once vehicle is started it runs fine, ipr 23 % hot idle, fuel pressure 55 psi. Only code in it when it came in was for a P0341. Has sync when cranking cold, I pulled valve covers and

powered the ipr - had over 4000 psi with no leaks. Had an ipr replaced a year ago and all 8 injectors. Stand pipes and dummy plugs are all replaced, ficm voltage looks good. Unplugged icp sensor with no change and vehicle will start normal every time when warm. Removed the oil filter and cranked, oil seemed a little slow to fill the housing but it did fill. Have 50 psi oil pressure on a cold idle and 18 psi on a warm idle. Only thing that seems suspect is I cant build past 40 psi oil pressure under load and WOT. I think I can rule out the high pressure oil system and P0341 which I'm thinking set when vehicle stalled. The bitch of it now is it doesn't have the really long crank since I started messing with it. If it sits for a while when cold it still has a slightly long crank and ipr is still going into the 60-70% range. I'm thinking a weak low pressure oil

pump. Any thoughts?

Jeff_E · May 17, 2017

STC fitting might have a tiny leak, not enough to cause problems under pressure yet, but maybe enough of an air leak for an issue if it sits long enough.

RyanG · May 17, 2017

Has the updated STC fitting. I'm thinking has a leaking o-ring under the pump allowing the reservoir to drain down. Its weird how it has become intermittent.

KDS · May 18, 2017

Stiction?

You might try plugging the block heater for a few hours or overnight.

See if it starts normally then.

High IPR DC can be a fuel system issue as well.

PCM can't control FP.

All it can do is jack up the IPR to try and get the fuel through the injector.

RyanG · May 18, 2017

With 2 new batteries and boost packs cranking for over a minute the pressure switch will not even come up. It will only build about 7-8 psi on a gauge. Removed the lpop and something went through it. Doesn't look like lifter bearings, I'm thinking some pieces of an old stc fitting. A few small gouges and the front cover has a pretty deep groove worn in. Selling a front cover with a pump.

Matt Saunoras · May 18, 2017

I've seen a lot of low pressure pumps with foreign object damage not related to lifter failure. Anyone's guess what goes through these things sometimes. Pieces of rocker arm, STC fitting, injector etc at any point in its history can leave stuff in the pan.

cbriggs · May 30, 2017

Usually with a low pressure oil system concern, the engine will fire, then stall in a few seconds, then become a long crank. Unless the hp reservoir is draining out, but I don't remember if it can drain back through the low side?

RyanG · June 3, 2017

Well I fixed the oil pressure issue. Had it all buttoned up and road tested. low pressure oil pressure ok now, icp looks good. I let it sit for 15 minutes and had a long crank. Now it intermittently will have a long crank hot or cold. I verified hpop reservoir is not leaking down. When long crank occurs ipr settles at 45-50% duty cycle and icp is reaching commanded pressure 1500psi or so when it wont start. Ficm voltage at 47 volts while cranking. Checked under the cam sensor no rust, new sensor. Pulled on the harness everywhere and cannot duplicate. Been messing with this thing for a week and out of ideas. Batteries are up, unplugged the alternator still does the same thing. Very random, no codes and runs great. It doesn't seem to matter if it sits or just got done driving it 20 miles, sometimes starts normally other times long crank. It seems that I even have the shut the key off and back on to get it to start sometimes. Any ideas?

Keith Browning · June 3, 2017

Well, despite all of the new parts no matter how new they actually are you obviously have a leak. New injectors and standpipes a year ago means nothing. You could have a seal that was damaged during assembly and has gotten worse with use. I would not discount anything at this point so If you have told yourself that it cant be under the valve covers it might be time to have a look and perform an air check. Intermittent to me suggests a bad o-ring. Many I have diagnosed were intermittent leakers that there was still some sort of sealing: not blown out but just deteriorated just enough to start causing trouble.

forddieseldoctor · June 3, 2017

Well, despite all of the new parts no matter how new they actually are you obviously have a leak. New injectors and standpipes a year ago means nothing. You could have a seal that was damaged during assembly and has gotten worse with use. I would not discount anything at this point so If you have told yourself that it cant be under the valve covers it might be time to have a look and perform an air check. Intermittent to me suggests a bad o-ring. Many I have diagnosed were intermittent leakers that there was still some sort of sealing: not blown out but just deteriorated just enough to start causing trouble.

That would be true if his icp was slow to build at times. But he said the icp reaches the desired psi. At least if I understood correctly.

My question is: Does sync and ficm sync come up when it starts cranking all the time? What is fuel pressure at when it has the long crank?

If sync or ficm sync are not responding normally then you need to use the oscilliscope and do the cam timing test and count the peaks VERY CAREFULLY. You could have a loose crank position trigger wheel.

Bruce Amacker · June 3, 2017

Don't look at ICP when you have a HP issue, only look at ICPV. The PCM could be substituting a know good value (BTDTGTTS). ICPV should be .24v KOEO, get to about 1.25V+ cranking within 3-5 seconds. Verify this on your next hard/no start.

Good Luck!

RyanG · June 5, 2017

Thanks for the input. Keith your right but sometimes its hard to get around the fact that something was just replaced. Time to go back to the beginning. As mentioned though, when long crank occurs icp will stabilize at around 1500 psi and ipr is hanging around 45-50%. Icp voltage is at .24v koeo. I threw one on anyway and it didn't change anything so that's why I was ruling out high pressure oil system. Fuel pressure does stay at 55 psi when long crank occurs.

RyanG · June 5, 2017

I thought about the possibility of timing issue but wouldn't that cause a running issue all the time? I thought if timing was off it would barely run or not run at all, power balance would be all over the place and so on.

forddieseldoctor · June 5, 2017

I thought about the possibility of timing issue but wouldn't that cause a running issue all the time? I thought if timing was off it would barely run or not run at all, power balance would be all over the place and so on.

Not always. It's a 6.0 anything is possible.

cbriggs · June 9, 2017

I have seen loose tone wheels on the crank start out as intermitant long crank/ hard start. You should be able to pick it up in the sync / ficm sync pids though.