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Hard starting hemi when cold

22K views 42 replies 14 participants last post by  NewBlue 
#1 ·
Hi,first post,I've been just a browser for a while but need some help,so joined today.I have a 2003 Dodge 1500QC 4X4 SLT Hemi that has recently decieded it doesn't like to start when it is left outside overnight when it's below 0* I have to crank it forever and pump the crap out of the accelerator pedal. I would like to fix this myself but just can't get anyone from the dealer or local repair shop to give me any input! I would guess it could be a fuel pressure regulator problem possibly,but again thats a guess,and apparently the fuel pressure regulator is inthe tank with the fuel pump and is pretty expensive to replace just going off a guess.Anyone else have any trouble like this and willing to help a guy out? The truck has 100000 miles on it and the only thing I have altered is I have the Superchip downloaded and taylor shorty wires,I tryed putting back the stock program but that wasn't it. Any help would be greatly appreciated,Thanks.
 
#2 ·
How many miles on the spark plugs?

Oh, and
 
#4 ·
I just went a bought a fuel pressure test gauge and it reads 48psi with the key on and 50-52psi running with the needle vibrating between the two. this is with a already warm truck so not sure if it would read different with the truck ice cold?
 
#5 ·
I'm also hearing that at that cold of a temp it could be flooding?and to depress the accelerator all the way and then back up to half way to tell the computer to not send it anymore fuel..."clear flood" mode? anyone else ever hear that? I wont be able to try until tomorrow when it's sat overnight...
 
#6 ·
 
#8 ·
Welcome aboard CJT - we're glad you found us!
The '03 model's fuel pressure should read 48 psi. The fuel pump/filter is indeed located in the tank - changing it out really isn't that hard and the assembly will run you about $125 (might be more since that price for me was back in '05). If it were me, before I'd mess with the fuel pump/filter, I would run a bottle of fuel injector cleaner for starters... see what that does for you.
 
#9 ·
clear flood" mode? anyone else ever hear that?
No! Leave a trickle charge battery charger on over night. See if that helps.
 
#10 ·
After doing more research and with the 48psi fuel pressure I have,I'm now leaning towards a TSB 14-002-05 with the actual throttle body!? I do run Techron through about 3-4 times per year,so I'm going to try cleaning the current throttle body and if that doesn't do the trick(my luck it wont!)I guess I'll get the updated throttle body. Is there somewhere on here to make such a purchase? I'm seeing them for around $130 or so and there is one one e-Bay now that I will make a bid on but didn't want to pay too much. I'll keep you posted and keep the ideas comming. Thanks again,Carl
 
#12 ·
I won a throttle body off e-bay this week the guy said the part number on the BOX was the one I was looking for, and of course when I recieved it the box was right with the OLD throttle body inside tryied it anyways same issue so I sent it back and am currently looking for the right updated part,is there anywhere besides the dealer to get one? Thanks
 
#13 ·
im having the same problem with my 04, it started after installing shorty plug wires , is it possable that the staggered spark from the old wires would make the differnce? only the 03 and the 04 had them i think
 
#14 ·
is it possable that the staggered spark from the old wires would make the differnce?
Good point. Guess it is pos.
 
#15 ·
Have you other guys that have this problem get the updated throttle body yet?I guess anything is possible but find it kinda hard to believe that having more spark would be bad and this would have been a problem for others way before now?
 
#16 ·
find it kinda hard to believe that having more spark would be bad
Actually, it would be less spark. With the short wires, the coil has to fire both plugs under compression. In the long wire, it fires one plug udder compression, and the other plug on the exhaust stroke.
 
#17 ·
and this would have been a problem for others way before now?
While I agree with yer statement, it seems the very low temperatures, are the root cause.
 
#19 ·
Now that I think about it when I put the shorty wires on I thought about it firing two plugs under compression and took a hint from my high compression snowmobile and set the plug gap on that one wire at .020" to make it easier to jump the gap. I might just buy a new set of plug wires to see if it could be it.
 
#20 ·
I am gald that Chrysler changed to both plugs firing under compression on all 06 and above Hemis
 
#21 ·
Thought I would update(since it's cold again!)The new throttle body did nothing at all!!...I have the shorty plug wires and it would seem it could be the wires but seems kinda unlikely to me,but I guess I could give that a shot...anyone else have anything to add? Thanks,Carl
 
#22 ·
well I switched back to the longer wires yesterday and left the truck outside over night. It only got down to 20*F which isn't all that cold, but it started up right away,so I guess I was wrong! I will leave it out again some night when it gets real cold <10*F or so and give another report but it looks promising at this point! Thanks again for all the help. Carl
 
#23 ·
I deffinitely want to hear how this plays out. I've got an '05 who has, on more than one occasion, not liked the cold morning starts. I was also going back and forth on the shorty plug wires when I change the plugs. I look foreward to hearing how this works out for you. Sorry you are going through all this trouble though..
 
#24 ·
I havnt had any starting problems in the cold since I changed the stock ig.coils for the MSD ones,,I do believe its a ig. problem
 
#25 ·
No problems here and it has been -45!!
 
#26 ·
I believe the problem is in the 03-05 hemi's ,,dodge went to a differnt coil set up in 06
 
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