while running a 2.0 MKIII golf in a recent rallycross (which is a blast), the fuse for the fuel pump blew. We have been chasing problems with limited sucess. We have many spare parts that we have swapped out on a trial and error basis.
The car now turns over and fires briefly, but after 10-15 seconds starts to run rough and dies out. There is a humming coming from throttle body. We have tried a backup throttle body with the same result.
What has been done:
Fuse Block: checked - all intact
Backup ignition coil: same results
Cap and rotor: inspected and changed
Thorttle Body: no change with backup unit
Checked fuel delivery: good
Tried multiple ECU's: no change
Chased wiring: no shorts
It seems that there is a sensor input throwing off the ECU..
Wondering if anyone has any suggestions to look into...
with much appreciation
98 VW 2.0 five door rallycrosser
94 90 CSQ - commuter and project
11 F-250 6.7L CC/LB
While cranking motor,get someone to smash the fuel tank(assuming the pump is still inside). fuel pump is half seized and by jarring it,it may run for a bit more than 10secs. Id be looking at the pump,popped fuse is the evidence.
Rallycross you say???? Maybe you starved the motor of oil from beating on it around corners and the motor is possibly partially seized. Check oil pressure too. Heard of guys sucking air from the pan instead of oil. baffles and oil squirters help.