EFI problems

[GQ Toy]

Have a 92 efi with 400 000+ on the clock, currently travelling around OZ and going to Cairns tomorrow.

The problem I have narrowed down to fuel, air or electrical . It is a pig to start, when it finally starts it runs fairly smoothly. Driving through the day I slowly lose power, I have nothing below about 2500 rpm and not much above it either. If I stop driving to open a gate and leave it idleing then accelerate to take if it will die completely and will run like crap for the rest of the day. It has no power and I have to wring its neck to get anywhere and don't mention hills. It pops and farts and misses all over the place below 2500rpm.

Fuel filter was changed 500km ago and it ran even worse, has new plugs, leads and dizzy cap. Diagnostics in Mt Isa did not show much at all - except the airflow meter resistance? was running just above factory spec across the rev range.
There is nothing blocking airflow and fuel pump appears to be working OK (will be checked in Cairns).
I am extremely frustrated as it has been getting worse over the last month or so - the mechanics I have spoken to all suggested electrical but the diagnostics did not show it. I will go to nissan in Cairns and get a download from the computer to check there as well.

Any ideas welcome, i will be back on tonight if people want further detail, other wise I need a good EFI mechanic in Cairns - any suggestions welcomed.

[Froon]

Might sound silly... but air filter?

[Rockwolf]

Froon, apparently nothing blocking airflow. Easy to check, though - take it out.

GQ Toy -
- any smoke, or abnormal fumes? Could be either burning oil or running really rich.
- Does it sound like it's pinging or missing? How's your timing?
- Losing any water from your coolant system? Water injection is nice, but not if you have too much, and in the wrong place.

Just ideas off the top of my head. Other things could be oxy sensors, MAF/MAP sensor not sensing correctly (and throwing off your fuel mixture). You mentioned your air flow sensor resistance was high, so I guess it's possible, though I thought that the signals they sent were voltage-related. How high? A touch, or a heap? Could try one from a wrecker?

No idea, really - maybe something will jog a memory from someone here. You know, from someone who actually does have a clue. :p

[WOZ]

Intank fuel pump is dying... or strainer on the bottom (unlikely). Aftermarket Subaru wrx intank pump fits perfectely. I`ve had 2or3 high mileage gq`s come through my workshop with similar simptoms and thats been the fix.Hope this helps Woz.

[Rockwolf]

Intank fuel pump is dying... or strainer on the bottom (unlikely). Aftermarket Subaru wrx intank pump fits perfectely. I`ve had 2or3 high mileage gq`s come through my workshop with similar simptoms and thats been the fix.Hope this helps Woz.

How would you check that? Fuel pressure? Interested, was something I didn't think of.

[WOZ]

Tee-piece fuel pressure gauge into high pressure line where it joins fuel rail. Should be about 38 psi at idle, and should spike up about 10psi when you snap the throttle. Also, to test pump reserve, CAREFULLY pinch return hose and check it makes at least 80psi.

[GQ Toy]

Cheers for the replies

Sorry forgot to mention air cleaner filter is new as well.

Thanks rockwolf - notice a few fumes but no smoke etc, timing seems OK, not burning any more oil than normal, not losing any water.

Cheers Woz, I am suspecting something like this, It will be checked in Cairns for sure. do the subaru pumps fit in long range tanks?, what year subaru?.

Have been changing fuel filters regularly and getting crap out so tanks may need a clean as well

[WOZ]

1995 to 2000 model wrx pump can be sourced with a goss number. If your long range uses a std gq efi pump this replacement will fit.
Cheers Woz.