Topic: EFI fuse blowing??

[Cheesemaker]

A buddy has a 91 p/u 22re that is blowing the EFI fuse.  Basically, you can start it and it will go about 100 feet and "pop."  He has checked all the grounds.  He is not very good at mechanics, and I wish I was closer since I have been trying to diagnose it over the phone with him.  

So, what are the top ten things to look for that would cause this?
I'm thinking he needs to pull the harness and start checking them with a volt/ohm meter.
And then onto all the injectors, sensors, and such.

What do you all think?


This all started all of the sudden.  Zero problems, then on the way home pop!

[twistedtoy92]

check the o2 sensor wires! I had the same problem back when i had my 89! it was just a wire that fell onto the exhaust pipe and was shorting out... popped the efi fuse about 3 times before i found it

[86turboyota]

i had the same problem but mine turned out to be the fuel pump.

[Toymin8r]

x2 on the O/2 sensor wire.  Mine melted to the exhaust pipe and was shorting out.

[lax815]

Had that happen to me a few weeks ago on my 91 3vze - it was the fuel pump.
Every thing was going good as I was accelerating uphill and it cut out suddenly and wouldn't start again.
Blown EFI 15A fuse and the old pump didn't turn with 12V on it  - didn't try a new fuse though, just replaced it and the pump (216000mi on the clock).
- Michael

[THK Matt]

x3 had it happen many times!

[bleakhorizon]

lol yea i have the same friend....  hmm one of us is gona have to get with em and take a look at it... start jiggling some wires, has to be a ground (or lack there of)

[WHITE_TRASH]

I chased and chased the same issue for a loong time about 4 years ago.  Sometimes the fuse would last a minute, sometimes a week.  I finally got pissed off headed home after a long graveyard shift and put a couple male disconnects on a short piece of wire.  Been that way ever since.

[83 Crawler]

check the o2 sensor wires! I had the same problem back when i had my 89! it was just a wire that fell onto the exhaust pipe and was shorting out... popped the efi fuse about 3 times before i found it

X3!!!!!! 89sastoy when threw the same problem and it was the o2

[MC387]

Looks like that fuse supplies the Fuel pump, the ecu, Both 02 sensors, And the Air flow meter.  It also goes to the check connector.

[THK Matt]

there ya go... check all the wires and make sure they haven't shorted out.

[swapped89]

same thing happened to me. o2 wires were melted and grounding on the exhaust by the cat.

[2manytoys]

Another vote for the O2 sensor wire. Happened on my kids 91 22RE. Was intermittent. When ever it happend to touch the exhaust it blew the fuse.

[bleakhorizon]

everyone is sayn the 02 is this the one on the downpipe,   i remember one of my 22rs had one down by the trans also, could that be the one grounding or do they even have one on a 22re

[Toymin8r]

everyone is sayn the 02 is this the one on the downpipe,   i remember one of my 22rs had one down by the trans also, could that be the one grounding or do they even have one on a 22re

The one by the cat is the one everyone is talking about.

[twistedtoy92]

yes, down by the cat.... (if you have a cat still)     

[crawlnbeaver]

it was the o2 on mine also... thanks everyone