Fuel Heater Faulty?

[joed]

Lately, now that the nights are starting to get colder, I've noticed my truck stumbles or hestitates while accelerating (after sitting overnight) until it warms up. Once the engine is warm, power is fine/acceleration normal. I've tested fuel pressure (warm only), and it's good, indicating the OPS seems to be working fine.

Could this mean the fuel filter heater is not working? Can it be tested? If it is bad will it store a trouble code(s)?

Thanks in advance. Joe.

[More Power]

The fuel heater is integral to the fuel filter assembly. It receives power via an ignition switched source, and activates via an internal thermostatic switch at temperatures of +20 degrees F or below.

A small air leak in the fuel supply line could cause rough running after an overnight shutdown. Try plugging the engine block heater in for a few hours before that first start in the morning. If having the engine warm helps or eliminates the cold start stumbling, the problem is heat (or a lack of it - i.e. glow, timing, etc.) and not an airleak problem.

MP

[joed]

Actually, it hasn't got down to 20 yet, only about 40, so there may be something to the air leak scenario. The truck starts fine with no visible white smoke.

I'll do more investigating. Thanks for the info.

Joe.

[CareyWeber]

Originally posted by joed:
Lately, now that the nights are starting to get colder, I've noticed my truck stumbles or hestitates while accelerating (after sitting overnight) until it warms up. Once the engine is warm, power is fine/acceleration normal. I've tested fuel pressure (warm only), and it's good, indicating the OPS seems to be working fine.

Could this mean the fuel filter heater is not working? Can it be tested? If it is bad will it store a trouble code(s)?

Thanks in advance. Joe. Joe,

The fuel heater is not a starting aid it's only there to keep the fuel from gelling in the filter and plugging it. The fuel that you start with is setting in the injection lines going to each injector the fuel heater cannot warm that fuel.

Diesel starting aids always effect the airm intake system of a diesel such as: glow-plugs, intake heater grids, and of course ether(aka starting fluid).

NOTE you cannot mix ether with any other starting aid!!

Block heaters and oil pan heater also help with cold weather starting, but they are different than a starting aid.

Here is a bit of diesel history too. IHC built diesels back in the 40's / 50's that did not have any of the above starting aids they used a carb and sparkplugs for starting. They had a carb, sparkplugs and distrbuter on one side of the block on the other a diesel fuel injection pump. They were started on gas and when they were running/warm they were switched to diesel fuel. To shut them down they would switch them from diesel back to gas to dry/clean out the diesel before they were shut off. If you failed to do this they were a bear to get running again.

Carey