Engine/Transmission (1994 - 1998) rough cold starts

[JBain]

I have noticed that after I installed a 4" exhaust that I get smoke out the exhaust on cold mornings and the engine is loaded up unless I use the block heater. I don't remember this happening with the stock exhaust. I there some reason this would happen with a less exhaust back pressure.



John

 

[Missouri Mule]

White smoke a pressume. Is it smoke or moisture? Is your intake heaters working (Is the voltmeter needle taking dive to the left every 20 seconds before starting)?

 

[KYOUNG]

Exhaust doesnt have anything to do with starting it, check your heater grids out.

 

[JBain]

The smoke is white and my volt meter needle does move to the left when I start the engine with it cold. If I sit and idol for a few menuites and not give it alot of fuel when I take off everything works fine. No white smoke. After the engine warms up no problem.



Can the heaters get less efficent as they age?



John

 

[EKlem]

The heaters don't really get less efficient, but since there are two, one can stop working and many people don't realize it.

Is your problem related to long cranking time, rough running when started up, or when you first try to go somewhere? Each of these has their own likely cause.

 

[KMumbach]

was having cold start issues, found bad intake heater relay. all is well now.

 

[Missouri Mule]

If your grid heaters aren't working on a cold morning you will blow white smoke.

Also white smoke is caused by not enough fuel /to much air.

 

[Vaughn MacKenzie]

Anytime you see more smoke than expected I always suggest doing the basics like servicing the fuel pre-filter and checking to make sure the fuel heater isn't leaking. Issues with the fuel system can cause air to be drawn up which results in poor fuel atomization and combustion yielding smelly white smoke. Fuel heaters are known to fail and melt, almost always causing a leak.

Pre filter service Fuel Pre-Filter Cleaning on Ram/Cummins

Also if your stock exhaust still had the catalytic converter then that may explain the increase in smoke after the 4" was installed. The cat will hide some startup smoke, that's what happened on my '98. It makes a small amount of blue smoke at startup and for the first minute or so after driving.

Another thing, it's better to put it in gear and start driving away almost as soon as you fire it up, not good for it to warm up by idling.

Vaughn

 

[JBain]

Thanks all, the white smoke don't bother me as much as the truck has no power like a 2 stroke engine when you first start it and it is loaded up with fuel but once you rev it a couple times it clears out.



Vaughn, I'll change out the fuel filter. I looked at the air heater connections and they are tight and no evidence of any melting.



John

 

[Joe G.]

If the fuel heater is fried there probably will be no external indication. What happens is that the contacts burn and heat up the pin in the electrical connection socket so that it sucks air around the pin. That is invisible unless you drill out the rivets and open up the fuel heater. Best to remove it any way because it's worthless.

 

[carson6]

heater relay(s) near battery made mine act the same way until i replaced it . starts good down to 10 degress with no block heat.

 

[JBain]

Thanks everyone, I replaced the fuel heater it was easy and the cost was less than the $42 on the linked website $27. There was some residue in the bowl that could have been blocking off a good portion the strainer. This is the first time I have ever changed it. I bought the truck in 99 with 53k miles and now I have 184k so I must be buying my fuel in the right place. At least it is clean.



John

 

[JBain]

I meant to say the fuel heater strainer.

 

[JBain]

I need some educating on the fuel heater. Does the fuel heater run all the time the engine is running or does it have a temperature sensor?

 

[Joe G.]

It would be nice if your sig had the year of your truck.

The fuel heater has a sensor. It's not on all the time. If the sensor burns up (common failure) or the relay sticks (not so common failure) the fuel heater will burn up and suck air at the electrical connection.

 

[JBain]

thanks joe, took your advise and added my year to my signature.



would the truck put out wihite smoke if the fuel heater was not working? an if so would it be all the time or just when the truck is first started on a cold morning?



john

 

[Joe G.]

I don't think the fuel heater can have any affect on smoke color.

 

[Missouri Mule]

The PCM turns on the fuel heater (thru a relay) when fuel temp is 40 F and turns it off when the fuel temp reaches 80 F.



As Joe stated should not have any thing to do with smoke coming out of tail pipe. It keeps the fuel from gelling.



Do a fuel pressure test see what it is when you first start it. You can check to see if the overflow valve is working at the same time.