Rought start, hard crank, sputter only when warm
 

I think I have enough of a specific problem to ask a question. I searched, but couldn't find the same problem...

1997 D1. 4.0L Runs perfectly. Fires up perfectly, when cold. 128K miles, been a very dependable truck.

New plugs, wires, head gaskets, fuel pump, intake gasket, starter, fuel filter (just changed it, and I can't believe how much it helped low end power) and maybe a few other parts I am forgetting.

when warm, it does start, but only after a lot of sputtering, and hiccup-ing, and once it is started, it runs fine, no issues at all. No CEL at all.

So, what gives? it must be an closed loop thing, because it only happens when warm. I just changed the fuel pump, fuel filter, and I though that would clear it up, but it hasn't.

Any help appreciated.

sounds like a fuel rail heat soak issue to me, but thats just a generic diagnosis. idk if there is anything more rover-specific to the problem.

The coolant temp sensor for the ECU will make hot starts a pita. Cheap, easy replacement. Get a copy of the "Rave" and take a look at the location of the ECU's temp sensor. There are two, one for the idiot gauge and one for the ECU. Normally the ECU's temp sensor will throw a CEL. Do you have a CEL? Codes?

The Fuel temp sensor can also cause this type of hot start. Like M&M said, heat soak. The Fuel temp sensor will increase the injector pulse length to remove bubbles that accumulate in the fuel rail. When they fail they do nothing, hence truck runs like crap due to air in fuel rail that takes awhile longer to purge. This also sets a CEL.

thanks
 

The car has no CEL. I will check/replace the fuel temp sensor, and I just did the coolant temp sensor.

I was also thinking a leaky injector. I will test and report back.

That works. Techron.

Don't forget to come back and let us know what fixed the problem..

Update
 

Still no codes, but I charged the battery, and the problems went away, at least for about a month. It started fine even when hot again and again. Last night, CLICK, then nothing like the starter solenoid, or maybe a connection issue. No crank, no start, nothing. Just CLICK.


Yuck. I did some research on starting issues, and will get to it thursday in 20 degrees and snow.

Problem solved
 

It was the nut that holds the hot wire on the starter, it was not tight, and charging the battery seemed to fix the hard crank, so goes to show you, sometimes its the easy things...

If easy involves getting up early and crawling in the snow, with 20deg and windy under a truck. But i'll take it.