Here I am

P1740 Code and can't start my truck after new six injectors installed! Help!

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

Ever see really loose mounting bolts on the 5.9 injectors?

Status
Not open for further replies.
Hi.
I just finished installing in six new fuel injectors today and when I went to start I get nothing. I turn on the key and my MIL or "Check Engine Light" light on the dash is real fast blinking and nothing happens when I turn the key to start but that. If I cycle my key three times I got a P1740 code which is my transmission coding I think. My OBDII tool doesn't see the ECM and error codes that way. Does the power need to be on the ECM for a while to reset it all. The batteries have been unhooked for three days.

I put the key in my truck (without starting before injector change out) to put the truck in neutral and push it farther back into my shop up close to the upstairs floor. When I got to where I wanted it, I turned off the key. Then put it back in park. I don't know if this caused the P1740 code. I disconnected the two batteries after that. I don't see how changing injectors would affect the ECM but these touchy CAM electronics that leave you stranded drive me crazy.

By the way the gear selector isn't showing on the dash. I had this last year and had to change the gear selector switch on the transmission. It checks out fine and I did nothing there in this procedure. I only unhooked the valve cover connectors, batteries and a sensor lead on the intake manifold. I did remove also the cable to the preheater on the manifold. It was touching the block at one point but after batteries were unhooked. It's almost like my ECM isn't there! Lights, radio, fan and those things still work.

Help! I need my truck soon for work! Thanks, Herb:{
 
Last edited:
Hi Bob, I check a bunch of fuses and they all look good. The ECM is clicking fast also to match the light on the dash. For tonight, I removed the grounds off the batteries and left the key in the "ON" position to clear the ECM. Have you ever had any codes and a no crank condition?
 
also check that none of the smaller wires got unhooked from the battery terminals. check the big bulkhead connector at the fire wall above the valve cover
 
I never did. sounds like the transmission is not getting power and wont let it crank because there is no park signal
 
I was under it with a torque wrench on the fuel lines and nuts. Things to look at carefully tomorrow.
 
Hi. I found the ground to the ECM was loose at the battery terminal which killed the ECM. I had the batteries returns still loose just in case I needed to unhook them quickly. Now I'm able to clear all the codes but it won't start. It turns over fine though. I can faintly hear the injectors clicking as they should. How long does it take to get fuel into a new injector install? I know all the feed lines were off during this process. On the older engines you need to bleed off the air but I was told these you don't.

Any advise? Thanks, Herb
 
All you need to do is perform about three key on key off cycles (bump the starter but don't start the engine) and this will prime the system via the lift pump......if it's working! Is your lift pump working?
 
Did you install the injectors following the "injector install with photos" thread I wrote a few years back or some similar procedure? Did the old injectors come out with the copper sealing washers still on them? Did the new injectors have the washers already installed? Followed the install and torque sequence? Without being able to see some of the data with a scan tool it is pretty hard to give you a good diagnosis.
 
Hi Sag2

Did you install the injectors following the "injector install with photos" thread I wrote a few years back or some similar procedure? Did the old injectors come out with the copper sealing washers still on them? Did the new injectors have the washers already installed? Followed the install and torque sequence? Without being able to see some of the data with a scan tool it is pretty hard to give you a good diagnosis.

Hi Sag2,
Actually I read the manual on the procedure to make sure my 2007 was the same as yours on your guide. I printed your guide out and then wrote down on a piece of paper a quick run down of all the torque procedures in their order to do it right the first time. I torqued the injectors to 44 in lbs and then loosened, then torqued the feed tubes nuts their first torque I think was 11 ft lbs. I then went back to injectors and did them again at 89 in lbs. I then went and torqued the feed tube nuts their final torque of 37 Ft lbs. I then installed the fuel lines and torqued them to 22 ft lbs. Something like that, just going on memory late at night. LOL

By the way, I rotated each injector to see if the feed tubes move back and forth and they did to assure they were paired. They all did equally.

Did I miss something? Thank you for the great guide and help! Herb
 
Another idea

I had the same problem it only takes one internal leak for it to not fire. Sag 2 procedure is spot on thanks Sag

I'm going to loosen and re-torque the front three injectors and feed tubes and try to restart it with the intake feed tube stuff off. I'll cover the preheater cable. If still a no-go I'll do the back hard to get to three if still not on.

I wish I had an injector plug off cap. I could unhook just one feed line at the common rail and plug it off. Try to start and go one at a time till it fired! Then redo that injector.

Anybody ever do this? Thanks, Herb
 
Hi Sag2,
I'lll recheck for all my copper seals. The new ones have new seals on them. I'll relook at the removed ones. i'm sure they are all accounted for. What do you think of my loosen and retorque idea?
 
They were thought to be good used injectors. One was bad. The solenoid on it tested crappy so I replaced it and thought that was the only issue. All the solenoids tested perfectly. I removed all the injectors today and reinstalled them using the multistep torque procedure and nothing changed. No start still. What a waste of time.
I'm reinstalling one of my original injectors tomorrow in the place of the possible bad one. I'm going to see if my Torx tube puller tool will fit my common rail fuel line connections. If it does, I'll unhook an injector one at a time at the common rail to plug it off temp. If pressure goes up I'll replace that injector!
 
I GOT IT RUNNING AGAIN! I removed the supposed bad injector that I replaced the solenoid on. I did cycle the key three times to do the fuel prime sequence! Replaced it with one of my original injectors and it started right up! Thank you for all advice and help! Herb
 
I GOT IT RUNNING AGAIN! I removed the supposed bad injector that I replaced the solenoid on. I did cycle the key three times to do the fuel prime sequence! Replaced it with one of my original injectors and it started right up! Thank you for all advice and help! Herb

I have sold good take out injectors as cores to keep anybody going through what you have
 
Status
Not open for further replies.
Back
Top