The glow plug in your engine is a consumable item which must be replaced periodically to maintain peak performance and starting ease.
First, test for a leaking glow plug. Place a few drops of fuel around the the base of the glow plug when the engine is cool. Use the EZ-Start® to spin the engine and look for bubbles around the glow plug. If the gasket is leaking, tighten the plug or replace the gasket.
The EZ-Start control box has an LED which lights to indicate the condition of the glow plug. If the LED does not light when the button is pressed, the glow plug element is broken. However, glow plug performance can deteriorate significantly before the element actually burns in two. The only sure way to test for a faulty glow plug is to replace it with a new one to see if the problem goes away.
You can view the glow plug element by removing it and touching it against the engine head while pressing the EZ-Start button. The glow plug will not light unless it is grounded against the engine. Glow plugs can be damaged by particles in the combustion chamber or by running the fuel mixture excessively lean. For example, running the engine completely out of fuel causes a lean condition which can damage the plug.
Traxxas makes three glow plugs. The standard long hot plug (part 3230) Is the replacement plug for the Pro .15 engine. The super-duty medium plug (part #3232) is the stock replacement plug for all Traxxas TRX 2.5 and TRX 3.3 engines. The optional super-duty medium plug (part #3232X) is also a medium temperature plug, so performance will be about the same.
Do not use plugs with idle bars! Glow plugs equipped with idle bars are not recommended for the TRX engines.
Notice the size of the two glow plugs shown above; the one on top is an extra long plug and is not recommended for use with the TRX engines. The one on the bottom is one of our starnard long glow plugs (part 3230). (Plug #3232 and #3232X are medium heat long glow plugs and are recommended for all TRX 2.5 and TRX 3.3 engines).