VU Bogging?

[Matty eco]

Hi guys
my 2002 VU ute feels like it is bogging (feels like a big flat-spot in the power curve) rather badly at 2-3k rpm at around mid throttle, and is worst in 3rd and 4th gear.
While its bogging however, if full throttle is applied the car will lurch and accelerate as normal.
This issue is starting to get worse and is becoming more and more noticeable.
I have already replaced the TPS and the IAC sensors.
Any help will be appreciated to get this problem solved

cheers

 

[AA6]

I had a very similar problem in my VS V6, is it very noticeable when hot and under load also?, if so you should change the ignition leads.

 

[Bowen]

I had a very similar problem in my VS V6, is it very noticeable when hot and under load also?, if so you should change the ignition leads.

HT leads, coils or dfi on the way out I'd reckon

 

[Matty eco]

I had a very similar problem in my VS V6, is it very noticeable when hot and under load also?, if so you should change the ignition leads.

It seems to happen no matter what the temperature is.
Going to replace spark plugs and leads and see if it still occurs

 

[Bowen]

It seems to happen no matter what the temperature is.
Going to replace spark plugs and leads and see if it still occurs

Symptoms very common of dfi module, instead of replacing leads just check the resistance, same with coils, u can change plugs they're cheap enough but was just thinking I case it's one of those you'll be able to tell without replacing!

 

[AA6]

In my case the resistance of the leads tested ok, but changing them fixed the problem. If I checked the resistance when the leads were hot it may have showed up?
But yea should check the resistance n go from there, if its been a while since the leads were changed it probably wouldnt hurt to change them too

 

[Joshua.Norman]

This might sound stupid but unplug the EGR and see if it makes any difference.

 

[Matty eco]

Symptoms very common of dfi module, instead of replacing leads just check the resistance, same with coils, u can change plugs they're cheap enough but was just thinking I case it's one of those you'll be able to tell without replacing!

Ok, but what should the resistance be?

 

[AA6]

If you search on here for ignition leads resistance you should find something.
Turns out that my car is still bogging a bit too, so leads didnt fix it, the car was at op temp, and going up a slope, in third just after 2000 rpm and yea, it was bogging =(
I have changed my coils about 1.5 yrs ago with new MSD ones, so Im thinking it could be the DFI module?...

 

[AA6]

Hey mate, any luck so far?

I found this thread, which was quite interesting

http://forums.justcommodores.com.au...3-1997/66579-up-hill-under-load-problems.html

It got me thinking, in my case the hesitation is only when hot, so shouldnt be injectors, right? I dont have any other DFI related probs, such as erratic idle, revs dropping or car cutting out, so perhaps the crank angle sensor?

All opinions are welcome =)