Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

95 VS V8 running rough & very sluggish, help!!!

Salan95VS

Member
Joined
Jan 20, 2019
Messages
46
Reaction score
2
Points
8
Age
27
Location
Wagga, NSW, Australia
Members Ride
95 VS V8 Ute
Hi everyone so my VS Ute has been running really well up until a few weeks ago.
Morning cold start: I prime the fuel system once & the tachometer jumps up to 2grand before it starts (takes about 3 seconds to start) then once it idles down it & warms up a bit it runs like it’s cammed as hell & you can hear the IAC whistling on & off trying to correct the idle, it also shakes the whole Ute & smells like raw fuel.

Warmed up: it’s very sluggish & when backing off it sounds like it’s missing. Idles rough at lights shaking everything ect & you can hear the IAC whistling on & off constantly, it also feels very harsh to shift & feels as though it’s giving the clutch/drivetrain a hard time.
Doesn’t throw an kind of codes at all.

I’m running out of ideas & really need help please as it’s starting to drive me crazy
 
Last edited:

Salan95VS

Member
Joined
Jan 20, 2019
Messages
46
Reaction score
2
Points
8
Age
27
Location
Wagga, NSW, Australia
Members Ride
95 VS V8 Ute
Things I have changed:
- IAC got changed end of last year
- O2 sensor (end of last year)
- IAT sensor (end of last year)
- Engine mounts (end of last year)
- Fuel pressure reg (a year ago)
- 9mm eagle leads ( a year ago)
- MSD Blaster2 coil & relocated to strut tower (a year ago)
- Air cleaner (6,000k’s old)
- fuel filter (6,000k’s old)
- oil & filter (6,000k’s old)
- coolant & Thermostat (6,000k’s old)
- new clutch kit (4 months ago)
- Fuel pump ( Aeroflow, 1 month ago)
- cleaned throttle body out a month ago
- spark plugs ( a week ago)
- VS HSV extractors, twin 2.5inch system, hollow cats & twin 3inch mufflers at rear (end of last year)
- New alternator (2 months ago & is charging)
- battery tested by century for 3 days & passed (last week)
 
Last edited:

gtrboyy

Well-Known Member
Joined
Jan 25, 2006
Messages
4,253
Reaction score
2,737
Points
113
Members Ride
vt ss & lc gtr
No codes I'd be looking at

cracked coil or wiring
swapping ignition module with known good one
rotor button,dissy cap & leads check with multimeter..also look for signs of arcing
earths or even add some

compression & fuel pressure test would be handy to rule things out.

When got vp ute had a lot of new gear on it yet ran like crap caused by aftermarket junk parts.

*sounds like it's dropping a cylinder or 2 if idling rough enough to shake car
 

Salan95VS

Member
Joined
Jan 20, 2019
Messages
46
Reaction score
2
Points
8
Age
27
Location
Wagga, NSW, Australia
Members Ride
95 VS V8 Ute
No codes I'd be looking at

cracked coil or wiring
swapping ignition module with known good one
rotor button,dissy cap & leads check with multimeter..also look for signs of arcing
earths or even add some

compression & fuel pressure test would be handy to rule things out.

When got vp ute had a lot of new gear on it yet ran like crap caused by aftermarket junk parts.

*sounds like it's dropping a cylinder or 2 if idling rough enough to shake car

Yeah righto I’ll definitely try & check all of those thanks heaps gtrboyy, I’m currently trying to get hold of an ignition module to test if mine stuffed as we speak but it’s proving to be a task.
When the battery specialist at Century put the battery back in & connected the earth lead after the positive it arced between the terminal & lead as it was going on, is this normal?
It’s definitely misfiring, when backing off it doesn’t crackle or anything anymore it just gets this drone & backs off really slow.
 

gtrboyy

Well-Known Member
Joined
Jan 25, 2006
Messages
4,253
Reaction score
2,737
Points
113
Members Ride
vt ss & lc gtr
Yeah man just going to have to go right through it again hopefully something simple...be easier if you had another 5.0 car or mate with one to swap parts over & get lucky that way.

Most of my mates would have issues after buying 'cheap' new parts usually some crap brand & get annoyed when put old factory part back on issue goes away

Sometimes you'll see little spark mainly from tap/touch as terminal goes on...if it arcs hard they did something wrong.

Earths on commodores get worse the earlier the model.
 

Salan95VS

Member
Joined
Jan 20, 2019
Messages
46
Reaction score
2
Points
8
Age
27
Location
Wagga, NSW, Australia
Members Ride
95 VS V8 Ute
Yeah unfortunately there isn’t many 5.0L’s where I’am which sucks a lot. I’am hoping that it’s only something simple but knowing my lucky it won’t be haha.

I try to spend the bit extra & buy original factory replacement parts where ever I can but sometimes the second hand part is the best.

Yeah righto I thought that was the case that there should be a bit of a spark but wasn’t 100% sure.
Thanks again for your help gtrboyy
 

delcowizzid

on holiday
Joined
Jul 8, 2008
Messages
6,988
Reaction score
445
Points
83
Location
NZ
Members Ride
в∞ѕтεכ √&
Throttle position sensor could be bad it effects shift pressure and idle decel etc .or the dizzy has moved
 

EYY

Well-Known Member
Joined
Mar 6, 2011
Messages
5,752
Reaction score
2,032
Points
113
Location
Vic
Members Ride
VS Statesman
That's an ignition module (I'd try module first) or dizzy problem for sure. Nothing else will make tacho jump like that imo...
 
Top