Glow plug light

my guess it does this only cold block. right. a key fact.
glow plugs failing
just because a lamp come on , dont mean much,
actual glow plug current is what matters. (proper)
only takes 3 things
proper compression.
glow plugs
fuel.

I assume there's a problem with alternator. Check the grounding to engine, check continuity of a positive wire between alternator and battery. the energizing voltage should be checked as well. Might be the bad connection between battery and vehicle body grounding. Diesel cars are sensitive even in a little loss of connection and rust in the connection points.

P0340 code means "Something" is wrong in the timing...
from CMP (Camshaft Position sensor) to the crankshaft bolt.

Very first thing, verify connectors are clean and shiny.
clear all codes, even hard codes.

Change the glow plugs and see if that fixes the problem.

THIS COMES ALL FROM "WAIT TO START" DO YOU WAIT TO START? IF NOT,THEN THE GLOW PLUGS ARE BUR'NT OUT,WHICH YOU WILL NOT NEED UNTIL FALL. OR MAYBE YOU'VE GOT IT HOOKED ON EITHER,STARTING FLUID,IN WHICH CASE,I SUGGEST YOU REPLACE THOSE GLOW PLUGS NOW.OR ELSE YOU'RE MOVING ON TO EVEN WORSE ISSUES.LET ME ASK YOU THIS,WHY ARE'NT THE GLOW PLUGS BEING DENIED POWER? AFTER ALL THEY START THE ENGINE? AFTER YOU INSERT THE KEY INTO THE SWITCH,WAIT TO START,LIGHTS UP.IF YOU'VE NOT WAITED UNTIL THAT WAIT TO START LIGHT GOES OFF,,,YOU'VE BURNT THE GLOW PLUGS UP.THE ONLY THING TO DO IS REPLACE THEM ALL.IF YOU'VE BEEN USING STARTING FLUID OR EITHER TO START YOUR ENGINE FOR A LONG PERIOD OF TIME,FORGET REPLACING THE GLOW PLUGS,BECAUSE YOUR ENGINE IS ADDICTED TO THE BOTTLE(EITHER) YOU MAY BE ONE OF THE LUCKY ONES,REPLACING THE GLOW PLUGS MAY RESOLVE YOUR ISSUES.BUT,WAIT TO START,,AIN'T NO JOKE. BEST OF LUCK TO YOU & YOURS!

i think glow plug replacement needed. ever used starting fluid in cold to start?try this, next time no start, cycle your key and let the light come on, wait till it goes off, turn key again until light goes off, if you have to do this more than 3 times, and it runs fine, replace the glow plugs only then. thank you for choosing fixya.com!

the car is going into limp mode due to an engine management fault. have to check what the fault is with a code reader. if the milage is high 100,000+ could be a turbo fault (overboosting), as this will put the car into limp mode.

Hello philkatkiele: My name is Roger and I will help you. First thing you need to check is the glow plugs. They will need tested individually. Un plug all 8 glow plugs. Take a test light and hook end to the positive battery cable. Touch opposite end of test light to the terminal end of the glow plug. The test light should light. Touch all 8 glow plugs. Ant that do not light are bad and will need replaced. If glow plugs are burnt out then the controller will flash wait light to early or very fast. The wait light should be on for approximately 10 seconds.If al glow plugs check ok then I would suspect the glow plug controller as the problem. Also if the temperature out side is below 40 degrees the truck should be plugged in. This will help to make the engine start easier. Should you need further help please just ask.Please rate the answer as this way I know it was helpful. Thank You for using Fix Ya. Roger

Check the glow plug thermo sensor...found in the cylinder head.
Unlightly anything wrong with injector pump.
Good luck
John

Hi Robert
From the brief description of your problem I'm guessing your vehicle is a Diesel? as the light you refer to sounds like the Glow Plug warning. When you turn on the ignition from cold the light comes on for around 5 to 10 seconds and then you start engine Yes?
If the light is coming on after vehicle is warmed up the glow plugs will upset the combustion and ruin your performance, so I would be looking at glow plug timer fault.
Hope this FixYa's problem!
Paul 'W' U.K.