Ive got a GDI galant thats caused me loads of problems since the moment i brought it. Its an early 97 4G93 with the green sticker high pressure pump. Its currently running rich and im struggling to find the cause.
Ill list the things i have done so far to correct all of the issues ive had.
-New fuel filters all round + air filter
-Replaced high pressure fuel pump as original one had gone low pressure
-Completely stripped, cleaned and serviced the throttle body and idle valve + checked TPS and correctly set the idle using a scan tool.
-Acid dipped intake manifold to clean the carbon buildup off
-Cleaned and tested injectors on an asnu GDI test bench + new seals all round.
-Replaced failed o2 sensor with a bosch universal 4 wire and checked its operation with a scan tool
-Tested all coils
-Replaced spark plugs with correct ones - NGK BKR5EKUD
-Checked temp sensors for correct operation with scan tool + thermometer
-Blocked off EGR valve (was running rich before i did this.. so not likely to be the cause)[img]
-Checked air flow meter and compared with a known good one using a scan tool
After doing all the above its running 1000 times better than it ever did and the economy isnt too bad either (500km odd to a tank around town and an easy 650km on the open road) but the plugs are still covered in soot, indicating its a rich mixture. The electrodes and tip are clean but the body of the plug is black.
The only thing that im not sure about is the fuel pressure. If it were too high i imagine that may not be helping but as its the earlier high pressure pump its got no pressure sensor on it, which makes it that much more fun to check. We have tryed adjusting the fuel pressure but it doesnt really make much difference. It runs fine to a point then runs like rubbish in either direction so ive put back to where it originally was.
Any thoughts or suggestions?