fuel ecu 30 amp keep blowing - Pirate4x4.Com : 4x4 and Off-Road Forum

Blackisis · 07-12-2004, 08:09 PM

I'm totally at a loss here, so any info/help would be welcome.
95 Wrangler 4.0 5 Speed
Blew my 30 amp fuse yesterday for the Fuel Control ECU. Replaced fuse and everything worked fine around town until I hit the highway where once again the fuse blew. Tossed in another fuse so I could limp home and it blew immediately.
Have spent the day trying to figure out whats causing this. I can't pull up a code, the fuel pump is fine, the auto shutoff works after 3 seconds like it should, but it wont start and it wont stop blowing the fuse. I'm working with a non-Jeep mechanic who is very good, but were at a point that we an't figure out whats causing this to blow. No shorts, bare wiere, bad grounds, etc. that we can see.

My only idea is to replace the computer, but I dont want to spend that kind of money unless thats a final option.
To make it worse I'm supposed to be driving 1400 miles this week to a Jeep Rally.

Like I said, any ideas would be greatly appreciated.

John

thenodnarb · 07-13-2004, 02:11 AM

replacing the PCM is not the answer. the PCM doesnt provide that kind of voltage to anything. id does, however, control relays through their ground circuts to power accessories etc...

99% of the time in this type of situation it IS indeed a short.
and what do you mean by the fuel ECU(electronic control unit?). The PCM (powertrain control module ie. computer)controls wether the fuel pump is on or off and the regulator regulates pressure. unless your refering to the cumputer as the ECU.

I bet there is a short in another accessory on the same circut( same 30 amp fuse) check to see what else is on that circut.

Suprsizit · 07-13-2004, 06:37 AM

Temporarily supply power to the fuel pumpfroma differrent source, direct from the battery, , if fuse continues to blow you will know it's not the pump. Fuse your temp power supply just in case it is the problem...

ItsaCJ6 · 07-13-2004, 10:37 AM

get diagram and begin looking for short on the same circut. PIA at best but the only way.

crazycj · 07-14-2004, 09:08 AM

Had same problem with mine, it was a short most likley look around o2 sensor, those wires hang sown and gett buggered. look for them shorting out

07-12-2004, 08:09 PM	#1 (permalink)
Blackisis Registered User Join Date: May 2003 Member # 19237 Location: Colorado Springs Posts: 7	fuel ecu 30 amp keep blowing I'm totally at a loss here, so any info/help would be welcome. 95 Wrangler 4.0 5 Speed Blew my 30 amp fuse yesterday for the Fuel Control ECU. Replaced fuse and everything worked fine around town until I hit the highway where once again the fuse blew. Tossed in another fuse so I could limp home and it blew immediately. Have spent the day trying to figure out whats causing this. I can't pull up a code, the fuel pump is fine, the auto shutoff works after 3 seconds like it should, but it wont start and it wont stop blowing the fuse. I'm working with a non-Jeep mechanic who is very good, but were at a point that we an't figure out whats causing this to blow. No shorts, bare wiere, bad grounds, etc. that we can see. My only idea is to replace the computer, but I dont want to spend that kind of money unless thats a final option. To make it worse I'm supposed to be driving 1400 miles this week to a Jeep Rally. Like I said, any ideas would be greatly appreciated. John __________________ 92 Range Rover, Hunter Edition, Red 95 Jeep Wrangler, Red

07-13-2004, 06:37 AM	#3 (permalink)
Suprsizit Registered User Join Date: Aug 2002 Member # 13207 Posts: 320	Temporarily supply power to the fuel pumpfroma differrent source, direct from the battery, , if fuse continues to blow you will know it's not the pump. Fuse your temp power supply just in case it is the problem... __________________ DSD

07-13-2004, 10:37 AM	#4 (permalink)
ItsaCJ6 Zeus of the Sluice Join Date: Aug 2001 Member # 6340 Location: Telluride CO, within site of of Black Bear Pass Posts: 3,929 Blog Entries: 10	get diagram and begin looking for short on the same circut. PIA at best but the only way. __________________ Marc In what appears to have been an understatement, the plant operator described the situation at the Number 4 reactor as "not so good." Super conversion calculator website Love and kisses, Zaphod..

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07-13-2004, 02:11 AM	#2 (permalink)
thenodnarb Registered User Join Date: Sep 2001 Member # 7252 Location: San Bernardino Mts, CA Posts: 459	replacing the PCM is not the answer. the PCM doesnt provide that kind of voltage to anything. id does, however, control relays through their ground circuts to power accessories etc... 99% of the time in this type of situation it IS indeed a short. and what do you mean by the fuel ECU(electronic control unit?). The PCM (powertrain control module ie. computer)controls wether the fuel pump is on or off and the regulator regulates pressure. unless your refering to the cumputer as the ECU. I bet there is a short in another accessory on the same circut( same 30 amp fuse) check to see what else is on that circut.

07-14-2004, 09:08 AM	#5 (permalink)
crazycj Registered User Join Date: Feb 2004 Member # 27860 Location: utah Posts: 19	Had same problem with mine, it was a short most likley look around o2 sensor, those wires hang sown and gett buggered. look for them shorting out