hard start in morning

[cummins]

i have a 2000 excursion driving me crazy, first start in the morning it cranks for a while before it will fire. when it finally does it runs with a miss, enough to stall it if you try to pop it in gear before letting it warm up, there is some white smoke during cranking, but just a litttle, if i plug it inover night , it will fire right up. after 5-10mins it runs perfect, no miss and it will fire up all day with 1 crank. i had a bad glow plug module, it was dead, i replaced it and it now works, but makes no difference on startup. so i pulled the valve covers, checked every conection and plug on both sides or the valve cover gaskets, no melting or burn marks. i checked for power at all 8 conectors to the glow plugs, and they are fine, stayslit for 2 mins. while i had the valve cover off i replaced all 8 injector o-ring kits with the latest ford part #'s and all 8 glow plugs anyway. i also replaced the ipr orings, the fuel filter and drained the bowl. all this made it run a little better, but made no difference on startup. i also replaced the cps, because it was cheep with a new ford part, and i had a spare idm and lift pump, so i swapped these out as well, makes no difference, i have done a couple of buzz tests over the last month and the first two and the last one sound weaker then the rest, but they do not pull a code. i have not searched which cyls these are yet, or on which side yet. it does fail cyl8 contribution test, and i am leaning twards injectors, but i do not want to throw any more parts at it. i want the next part to fix it. the truck does have 250k on it, but warm or cold it has no blow by from the oil cap or dipstick, i bought a harbor freight comp tester to to a comp test when i did glow plugs, but it will not fit between injector and pushrod. truck uses no oil, leaks not a drip, and gets 23mpg on the highway, 17 around town, so i do not think the motor is worn. shoule i replace all 8 injectors if they are the culprit, or just the bad ones, anyone have a good inexpensive source for injectors? are there any further tests i can perform?

PLEASE HELP ME!!!

[NCHornet]

STOP!!
Please don't go throwing parts at this thing, let's take it one step at a time. First of all what are morning temps where you live? Most places in the USA it's fairly warm, so you can eliminate the GP system, besides you have tested it and know it's working. Drain the fuel bowl, turn the key to on ( not cranking) wait for WTS light to go off, check fuel bowl, is it full? If this is good you have fuel which is good. Next in the morning when you are having problems, I want you to take a multi meter and check battery voltage while sitting and then while cranking. My money would be weak batteries. A PSD requires full power batteries, if they are slightly discharged it will be a real bear to start, this would also explain why it starts fine the rest of the day after first starting it, and when it's plugged in, sometimes a few degrees can make a big difference in batteries. Make sure you check both batteries. Don't just go to the auto parts store because they will probably test good, but as I said we need great batteries not good.
The other idea I would put money on is you have air in your fuel system. Many folks experience hard, really hard starts after changing injectors, the best way to get the air out is run it like you stole it, really hard, this will purge that air out. I would place my bet on weak batteries first. Check what I have mentioned first and get back to me. What are you checking codes with?
NCH

[cummins]

i am a ase cretified tec, but not a diesel expert. i have already gone through the basice, i guess i didnt cover everything in the first posting. i have a snapon modis scaner and this is what i am doing diag with. i checked the bateries first thing. one failed load test, and was replaced with a brand new one. the other is only a couple or months old. 1000 cca. i resurfaced all battery contacts on the batteries, and checked and cleaned all connections to the block. dosent go below 11volts during cranking. i have eliminated batteries as a problem. it is in the 50's in the morning and dips in the 40's at night. buy all the glow plug wiring has been hand checked, glow plugs are new, and relay is new, relay was bad but made no difference on startup. lift pump checks out, and it is not a fuel delivery problem, at least pre filter. i have read a couple of threads last night, there seem to be some people having the exact same problem, and poeple have suggested injectors, but nobody replies if this has fixed anything, or if they fixed their truck at all. the only thing i dont get is why it will start in the morning no problem only when pluged in if it is an injector. i realy will be upset if i put in a set of injectors and it fixes nothing. that would be a $1000 twards a cummins swap.

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Last edited by cummins : 05-23-2008 at 06:27 AM.

[NCHornet]

Wish you would have mentioned the batteries would have saved me some typing, lol!!! Also it is always advised to replace both at the same time, otherwise the weaker will draw off the stronger, but I am sure you know this being a tech, just thought it may help others who read this. Injectors usually don't work and then don't work or work only when cold so I would rule that out. Have you checked the oil level in the HPOP? Remove the allen head bolt on the top of the HPOP and see how low the oil level is. Should be within a 1/2" of the top. Your injectors are fired by high pressure oil, if your HPOP is leaking down to the LPOP it a can be a real pain to fire up, it may be a slow leak that takes overnight to leak down, would explain once it is fired up it does fine. Check this and let me know.
Are you sure your scanner doesn't need the PSD bundle software? Our trucks are not OBDII compliant and a OBDII scanner without the specific PSD software won't read the codes?
PS, if you think the Cummins don't have problems too you should take a look at the Dodge forum!!

NCH

[cummins]

there was so much work done and checking that i could not remenber it all. i have checked hpop level numerous times, i have checked it before cranking, the level is within 1/2 inch of top. oil is changes regurally with 15/40 rotella, always has been since i have owned it, and i have also changed it since i have had this problem. when i had the valve covers off there isnt any sludge or buildup anywhere, looks loke it did when it was new. i have no problem accessing any functional tests, or data stream using the scaner so i assume it has software needed. incase i havent mentioned it there is a nmiss on cold start, goes away within 5 mins, if i plug it in it will start perfect, no miss. i have been reading some other threads, i cant find it now, but i did lastnight, he said he has a fleet of busses, and a couple of them have the same problem i am describing, said he put injectors in one and it fixed it, but was looking for a way to diag which ones were bad as to not replace all them in the other busses. i also read some othere saying the worn out injectors dont function properly when cold, but fine when warmed up. i just do not understand why mine fires right up when pluged in, glow plugs work fine, and it was in the 60's thin morning, still had a problem.

[NCHornet]

To eliminate the injectors run the buzz test, and let us know what happens. Just google Injector Buzz teast, your Snap on scanner may perform it, if not do you know anyone with AE program?

NCH

[cummins]

i have ran a couple of injector tests, come up with no problems, 3 sound weak, but do not fail, contribution test is no help because it will only perform hot, and there is no problem when it is hot, i am stuck, and i thought i would see more useful help form people with the same problem,