Jump to content
  • Welcome To Mopar1973Man.Com

    We can see that your guest and been lurking about. When you register on the Mopar1973Man.Com site you'll be able to interact with all the other members. This is the most friendliest Cummins forum you'll ever join. Take the time right now and  REGISTER  on the Mopar1973Man.Com this will open up many more options and functions on the website. Everyone is very friendly and helpful just ask questions and everyone will help you out the best they can. 

Recommended Posts

What could be a possible cause of a long crank when the motor is hot?

Starts great when cold

Fuel pressure constant 17 psi

Cranks great

Thanks in advance I won't have internet access till first of the week

 

Share this post


Link to post
Share on other sites

PSG on top of vp my first guess. Other than that could be a number of things. Try dumping water on vp next time and see if it helps. This was an issue with early vps.

 

  • Like 1

Share this post


Link to post
Share on other sites

That was my thought also just hoping it was something else. I have replaced it twice already. Thanks for the response

Share this post


Link to post
Share on other sites

Lets put it this way PSG overheating is extremely rare. I would say the fuel pressure being to high during cranking being more of a cause. No more than 12 PSI while cranking. If above 12 PSI hard starts happen.

  • Thanks 1

Share this post


Link to post
Share on other sites

Wired a relay in that cuts power to the LP in start position.  Went to to the store this evening seems to be starting good now,  will know for sure Monday after towing the RV this weekend.  Thanks moparman1973 for the tip, sure better than another VP.

Share this post


Link to post
Share on other sites

Is your Fass not connected thru a relay triggered by the oe harness?

Share this post


Link to post
Share on other sites
1 hour ago, mountaindan said:

Wired a relay in that cuts power to the LP in start position.  Went to to the store this evening seems to be starting good now,  will know for sure Monday after towing the RV this weekend.  Thanks moparman1973 for the tip, sure better than another VP.

I did that with the last IP I had because of hard hot starts. Worked for a while. I used 2 relays in line to power the LP. 1 triggered off the ECM and 1 triggered off the power window fuse. That way the ECM is still in control, but power is cut 100% when cranking. Remember if the pump is wired to a key on hot and you're in a wreck the pump will keep running pumping fuel on the fire if there is one. Just something to think about.

  • Thanks 1

Share this post


Link to post
Share on other sites
1 hour ago, mountaindan said:

Wired a relay in that cuts power to the LP in start position.

 

Let me know if this ends up being a good long term solution. I was thinking about doing this.

  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)

This is so you don't have to wire anything in, just replace the relay with this one. As long as you have an aftermarket harness that comes with Fass or airdog, otherwise you'll have to wire in a relay base a factory setup. 

https://m.delcity.net/store/Time-Delay-Relays/p_804415.h_804416.r_IF3003?mkwid=8TgfXoca&crid=11472933143&msclkid=244a8de769fc10e0a1ddd14a10340b58&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping - PLA's(BSC)&utm_term=1100315444392&utm_content=Ad group %231

 

Edit 

I'm just reading the instructions on this relay and it's working opposite from what we need, it keeps things powered on after the ignition is off not the other way around. 

Maybe there is another one that does the opposite:think:  @IBMobile

Edited by Dieselfuture

Share this post


Link to post
Share on other sites

That's a neat idea. Need an on-delay relay instead of an off-delay relay. Except then your key-on prime will get shortened, or cancelled.

  • Like 1

Share this post


Link to post
Share on other sites
47 minutes ago, kzimmer said:

That's a neat idea. Need an on-delay relay instead of an off-delay relay. Except then your key-on prime will get shortened, or cancelled.

Yeah but I don't think it will be a huge deal, mechanical pumps don't prime ether. The only other thing is if it's cold and you have to wait for wts to go out. And the initial key on sends juice to relay and if it's when it triggers it then not sure if it will work ether. Beyond my thinking. 

Share this post


Link to post
Share on other sites

Why not just measure the fuel pressure and adjust it to so in not exceeding 12 PSI at cranking. Pretty simple eh? 

 

My AirDog is set for 17 to 18 PSI at idle and cranks right at 10 to 12 PSI no issues. Most people have them turned up way too high and wonder why the hard starting. 

Share this post


Link to post
Share on other sites
12 hours ago, dave110 said:

I did that with the last IP I had because of hard hot starts. Worked for a while. I used 2 relays in line to power the LP. 1 triggered off the ECM and 1 triggered off the power window fuse. That way the ECM is still in control, but power is cut 100% when cranking. Remember if the pump is wired to a key on hot and you're in a wreck the pump will keep running pumping fuel on the fire if there is one. Just something to think about.

What do you mean "worked for awhile"?

Share this post


Link to post
Share on other sites
56 minutes ago, Mopar1973Man said:

Why not just measure the fuel pressure and adjust it to so in not exceeding 12 PSI at cranking. Pretty simple eh?

Keep it simple.  Doing an adjustment is a lot easier than doing a lot of rewiring.

If that doesn't work you might try this.

 

 

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

Just returned from our first camping trip this year truck performed great, thanks to everyone for the suggestions and especially Moparman1973 high pressure seemed to be the problem.

Share this post


Link to post
Share on other sites

Thanks @IBMobile, I've been looking for a wire that's switched with engine running. I'm going to use it to disable the grid heaters through a 200 amp solenoid I got off of Amazon while the engine is running. I think it's the simplest way to protect the alternator from the grids. Sorry to get the thread off topic.

 

Share this post


Link to post
Share on other sites

@kzimmer, I will be installing a different type of grid heater control on @JAG1 truck next weekend and doing a write up on that if you can wait and see what it is.  

Share this post


Link to post
Share on other sites
2 hours ago, kzimmer said:

Thanks @IBMobile, I've been looking for a wire that's switched with engine running. I'm going to use it to disable the grid heaters through a 200 amp solenoid I got off of Amazon while the engine is running. I think it's the simplest way to protect the alternator from the grids. Sorry to get the thread off topic.

 

Usually threads aren't off topic till Mike posts a picture of one of his girlfriends. :burnout:

  • Thanks 1
  • Haha 3

Share this post


Link to post
Share on other sites

I think IBMobile saved a picture of her. 

Share this post


Link to post
Share on other sites

                    He met her in Ontario when he was riding his bike.

                          362979519_Hippie-Chick1.jpg.d0078aba1b953fe8d3d9d0b90f58279f.jpg

                                

  • Haha 2

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  



×
×
  • Create New...