RB20DET Bogging?

**Evans** · 11-24-2011, 01:21 PM

I'm starting to run out of options im not sure what is happening with this car, i daily drive it and need it for school. the problem has gotten progresivly worse since september. i have minimal modifications done to the car. coilpacks have been inspected, no visable spark leak and new oem copper type plugs have been installed last 200km. the car starts cold in the morning and idles fine until operating temp is reached. after that the bogging starts and all power goes out the window. the cat is already empty, runs on 91 octane, MAF is cleaned regularly. today i will check for codes on the ecu, double check wiring harness for each coil pack. after that i have no more ideas.

**amnash** · 11-24-2011, 01:24 PM

plum a geuge into your fuel system to inspect your fuel pressure.

**MKIV** · 11-24-2011, 01:27 PM

What caused my RB20 bogging was several things. A cracked IACV, MAF sensor wires were tangled, BOV location and open venting.

1) Check your MAF wires. Make sure they aren't too tight or even cut/ripped.

2) If you have a blow-off valve that is not recirculating, it should be as far from the Air sensor as possible. Also BOV that stays open longer will cause the motor to bog. I had this when I first got my car. It bogged even at idle.

3) If none of the above, check your fuel pressure. Have any lights came up on your dash?

**Evans** · 11-25-2011, 12:32 AM

today i checked the compression. lower than expected but still a pass. cylinder 3 is for sure the main problem. possibly another cylinder is out but i cant reach the back one. all coils are producing spark. i suppose the only thing left is the fuel system. i didnt see any visable leaks. i will pressure test the fuel system tomorrow. is there any chance that my injectors or rail are plugged? the local gas stations are notorious for bad gas but could debris really pass the filter and plug an injector? any more thoughts will be greatly appreciated. i am in desperate need for a fix.

**Supraclean** · 11-25-2011, 01:25 AM

I would hook your ECU up to a Dataloger/ OBD code reader to see if theres any codes. No one mentioned O2 sensor Id check there. Also you notice it only under throttle correct?

Is it over heating?

**MKIV** · 11-25-2011, 11:17 AM

Replacing fuel filter is always a good idea while you deal with this problem. Check entire fuel system. Hopefully your fuel pump is good, I experinced fuel starvation in the summer, similar issue, and it wasn't fun at all.

**Evans** · 11-26-2011, 03:44 PM

it does over heat but only if im in grid lock traffic. il take a look at fuel filter prices and see if changingmy coilpacks around changes anything. thanks for your help guys, hopefully everything is back to normal.

**Evans** · 11-26-2011, 05:59 PM

well today i was mucking around under the hood and took out cylinder 3 coilpack and replaced it with cylinder 1. and you'll never guess what happened! cylinder 1 started to missfire and cylinder 3 was fine! wow imagine that. the most obvious issue with the RB engine was in fact the problem. i suppose when the engine was cold the resistance in the coil pack was in an acceptable firing range but once operating temp. was reached the resistance went out of spec. 137,000km not bad for stock coils right? now i need to find the replacement. thanks for your time you guys.