Jim Grant's Tech Tips
'98 Dodge Intrepid, No Start When Hot
My 98 Dodge Intrepid
has 120k and I have replaced the EGR, A.I.S. motor, M.A.P. sensor battery
terminals and all the other sensors on the intake plenum have been cleaned.
When I drive the car for about 50 miles shut it off and go out to start
it 15-60 minutes later it will start and stall, run rough and die. I can
start it and put it in gear fast enough and tickle the gas and some times
I can drive away. The fuel pump, filters, injectors were done at 65,000
miles. When I did the EGR I took off the intake plenum and cleaned the
carbon out of that also. Everything has been done to torque specs. No
engine lights stay on, temp gauge is normal and idle is at 550 in drive
when hot. One dealership suggested that a heat sensor was causing the
problem. What do you think?
- Jim M.
I think youre
having a fuel pressure problem. But it is going to take a little proving
to answer that question. If fuel pressure is too low it will cause air
to form in the fuel injection system. This condition is compounded when
the engine is hot. If you play the throttle just right you can keep the
engine running (as rough as it may be) long enough to purge the air from
the injection system. Once the air is gone the engine runs smooth again.
The reason I do not believe that the condition is being caused by a heat
sensor? Does your engine ever run as bad when it is running and hot already?
If a sensor was failing or lying because of heat you would notice the
condition while the vehicle is running. To prove this would require installing
a computer scan tool and monitoring the different sensors. Just call the
repair facility that you do business with and schedule your vehicle for
the return trip of a 50 mile drive. Just 15 to 30 minutes with some diagnostic
equipment at the right time could answer a lot of questions.