Bogging issue still occurring.

[Prelude Guy]

Hey all,

Here is my original thread; http://nicoclub.com/zerothread?id=80665

Well, I just finished replacing the fuel pump (Walbro 255) and the car still hesitates/bogs.

I am SOOO pissed right now. I am not sure what to do here. Should I take it to the dealer now??

Timing?? MAF??

[s13sr20chris]

do you know if its ign or fuel? you may have to go dealer but as long as you try fighting it we will help you.

[Prelude Guy]

Let me recap on what has been done to the car (89 240SX Hatch SE)since I got it.

Items changed:Distributor capRotorSpark plug wiresSpark plugsO2 Sensor300ZX TT fuel filterWalbro 255 fuel pumpNegative battery terminal

I checked the engine bay for vacuum leaks. I found the hose underneath the BPT (thing attached to the intake manifold with 3 tubes going to it.) with a pretty good sized hole. I replaced the hose. No difference.

I have disconnected the AIC device (the black contraption that allows exhaust fumes back into the intake box near the air filter)

I plugged the EGR valve.

If I unplug the MAF, the car dies out almost immediately

If I unplug the TPS, the car almost dies immediately

I put injector cleaner and filled up with Premium gas. I used intake cleaner too.

Oil has been changed.

I ran another ground wire to another point on the chassis.

I am not throwing an CEL or codes

The battery light lights up on the dash half way at idle and slowly fades out as the RPMs increase. However, it never totally turns off. This is the ONLY other thing that I see wrong with the car. It idles pretty well too.

At idle, if I push the gas pedal down more than 15%-100% of the way to full throttle, the car bogs BAD! It will rev from 500-1000 rpms in a repetitive sequence. However, less than 15% of full throttle, the car revs almost perfectly fine. Same thing happens while driving on the streets. The car accelerates better if I slowly push the pedal down and to a certain point. Beyond that point, the car will bog.
Modified by Prelude Guy at 10:45 PM 9/15/2004

[180fan]

so how's the timing?

[Prelude Guy]

That's the next thing that I am going to check.

Also, when I push the gas pedal down more than 15% of the way down, I can hear the intake sucking in a lot of air. The car just doesn't want to go.

This leads me to believe that it is an ignition/fuel problem.

I will check the timing soon.

[Prelude Guy]

New info.

I took the car out for a test. I noticed that if I rev up the car in neutral, when I get to 4000-4500 rpms...the light on the dash and the clock start to flicker and the battery light starts to light up brighter.

[Prelude Guy]

Also, how can I check my ignition coil??

[s13EastTN]

The light might be your alternator. A bad would would cause weak power, and higher revving would make more power, but still low enough to cause that light to come on. If you hear your intake sucking, it might be a vacuum leak. Spray some carb cleaner around all of the vacuum hoses and if the car sputters or dies then you have a leak there. My 240 ran like crap, backfired, barely started and had no power. Found out I had a small hole in a vacuum line, fixed that and it fixed all my problems.

[JNM240]

Also check your coolant temp sensor connection. They are know for getting corrosion in them causing the ECU to read the engine as cold and dump excessive ammounts of fuel in. That would cause it to bog.