Not going above 3,500 RPM's and hard to start when it gets hot

Tiny
STEVEN121261
  • MEMBER
  • 2003 DODGE RAM
  • 4.7L
  • V8
  • 215,000 MILES
Put cam sensor in crank sensor in put. Put MAP sensor in putiat sensor in and when it is hot it will not start.
Thursday, September 6th, 2018 AT 7:44 PM

6 Replies

Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
I would bet on a weak fuel pump with that many miles on it. Stop by the local parts shop and borrow a fuel pressure test set from their loan-a-tool program. Then follow the instructions that are in the attached image.

Also, here is our more general how-to guide on testing fuel pressure: https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Check the pressure and let us know what you find. We will go from there.
Was this
answer
helpful?
Yes
No
+1
Friday, September 7th, 2018 AT 5:23 AM
Tiny
STEVEN121261
  • MEMBER
  • 3 POSTS
Thank you, but when it is cold it runs great when it gets hot it is hard to start.
Was this
answer
helpful?
Yes
No
Friday, September 7th, 2018 AT 8:31 AM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
I understand that. Sometimes a bad pump will be okay until it warms up a bit. Then the pressure drops a bit and it runs really bad, if it runs at all. My dad's 1995 Dodge Dakota did that. When it was cold, it put out something like 40 psi. Once it warmed up, the pressure output would drop to about 22 psi, and the truck would not do much more than idle.

One question though, is the service engine light on?
Was this
answer
helpful?
Yes
No
+1
Saturday, September 8th, 2018 AT 3:37 AM
Tiny
STEVEN121261
  • MEMBER
  • 3 POSTS
I am getting a p0116 and a po558 and a po339 and a po594 when it is hot.
Was this
answer
helpful?
Yes
No
Saturday, September 8th, 2018 AT 6:47 AM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
P0116 - Engine coolant temp sensor circuit range/performance - could cause your running issue
P0558 - Brake booster pressure sensor circuit high - likely not related.
P0339 - Crankshaft position sensor "A" intermittent - can cause all sorts of running issues
P0594 - Cruise control servo circuit control open - likely not related

The images below address testing the coolant temperature sensor. I will address the CPS in the next post.
Was this
answer
helpful?
Yes
No
+1
Monday, September 10th, 2018 AT 4:02 AM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
Here is the information on testing the CPS:
Was this
answer
helpful?
Yes
No
Monday, September 10th, 2018 AT 4:08 AM

Please login or register to post a reply.

Sponsored links