1998 GMC Yukon wont start

Question

The truck ran fine yesterday and I checked the fuses inside the truck and the ones under the hood in the relay box and they all look good. The motor turns over it just wont start. Any suggestions?

Answer 1

You need three things for a vehicle to run, fuel, spark, compression.  If the truck ran good just recently, and these trucks are known for bad fuel pumps, I would spray some carb cleaner or pour a small amount of good fresh gas down the throttle body.  Simply remove the air cleaner duct and spray the carb clean or pour the gas down and put air cleaner duct back on.  Then try to start.  If the truck runs and stall immediately, you have a fuel system problem, most likely a fuel pump.  Mine just died the same way and replaced it now all is well.

If the gas trick does not let the truck run, I would next check the spark and last the compression.  Good Luck.

Answer 2

Dude, the problem is your ignition system is locked out from the secuirty system.  Somehow you have the alarm in lock out mode, where it will shut off the fuel pump.  It will crank all day, but it's not gonna get any gas unless you get the theft deterrant system, to unlck.

Answer 3

IGNITION, OR YOUR CRANK SHAFT SENOR, DISTRUBITOR.

Answer 4

make sure all connections are tight and not rusted. also you might want to try to hook the battery directly to the starter to see if its the starter thats the problem

Answer 5

Check for spark outputs at the plug ends while your buddy turns the motor over. Should be strong and consistent for each plug. Check fuel pressure at the schraeder valve close to the fuel injectors. Needs to be around 55 psi. Also check for computer health, check codes and data to see if it looks close to where it should be regarding temp and stuff that common sense would tell us.