Loss of power...

[jazza21]

I have a '97 VS, and gradually over the last few months I have noticed a marked decrease in the amount of power my poor baby can put down on the road.

Example - travelling 110Kph, start going up an incline... Car drops gears from cruising in 4th at 2000RPM to 3rd at about 3000RPM. Incline and/or speed increases so car needs more power to retain speed, tries to accelerate (I've got cruise control on) but there's no increase in RPM so Auto kicks down... TO SECOND!!! Think what RPM it'll be doing in this gear and you know how freaky this would be... Especially in traffic, and it does not accelerate but slows down more because there's simply no guts there.

Then there's this - when I accelerate from standing or just in general the car seems to reach a point in it's rev range (the 3000 RPM mark) where it just won't upshift, spinning like buggery and hanging on to nothing. I'll go up a hill in an 80 Km zone and it refuses to get out of second and/or third, just seems to hold it like a last resort ditch at power even though there's none there. It feels as if the car is wheezing or just running out of steem, like it sorta shudders, you can feel mini-spurts then they weaken. I have to ease off the accelerator a little and then it will relax, but even then it still wont get the guts together to get it over the mark.

Basically I have no power/torque above 3000 RPM. It's not the Auto, I had that checked out last week. Another thought has been I think I have dodgy spark leads... I don't have genuine Holden ones, they're "Top Gun", ones on there when I got the car over 18 months ago, and so far as I can tell they only make these now for Supercharged engines... I know the plugs are Ok, I put Bosch Super4's in and they improved it marginally but still no fix. Other possibilities have included the Coil pack, and also the TCC solenoid in the Auto not working as well as it used to (eg slipping transmission). I have also thought it could be the road-speed sensor telling the Auto the wrong info, or the Thottle position switch has been recommended by a mate.

Any suggestions?

Jazza

 

[hako]

Jazza - I'd be looking for a restriction in my exhaust...possibly a catalytic converter which is crumbling inside or has a blocked matrix. When the cat blocks you will lose power gradually as it gets worse to the point where the engine will only idle. I'm not sure if you can unbolt the cat to look inside at the matrix on the Commo - I know on Astras you can.
Good luck.

 

[Michelson4301]

I'm with hako, check air filter and cat by undoing the 2 bolts on the slip joint on the back of the cat. If both of these check out i suggest you try another set of standard plugs as 1. they are cheap 2. i have heard of funny problems happening with these plugs as you have described. P.S probably cat breaking down though

 

[jazza21]

Thanks for that guys

I took my poor little baby to Armstrong Holden on the weekend and asked for some "technical advice". The guy was very helpfull and looked at the car for me, and advised me of some things I need to do.

Firstly he said that I need to replace the wiring loom between the back of the alternator and battery/fuze box. The wire originally installed at the back of the alternator at manufacture isn't strong enough to handle the higher output from this larger component compared to older models (VR's etc). He said it was a common problem up through VT's as well, until they realised and upgraded the harness. You can see if yours is going by looking under the rubber cup thing that sits over the connector at the back of the alternator. If it's got black and grey powdery stuff there then it's shorting and wont last too long. My car had heaps of error codes thanks to this problem, mostly readings of too high/too low voltage. This in turn made the Air Bag light come on too. He cleared the codes and there has been a mild improvement in performance, but I have to replace the loom ASAP ($77.40 from the parts guys there).

Last but not least the place I went to that looked at my Auto and 'serviced' it did NOTHING!!! Bastards... We went for a test run around the local area and the guy basically said my Auto is screwed, this being the problem that has caused my lack of power. Here comes an expensive exercise I think...

I am wondering... Shorting of the wires will lead to less overall electrical power to the rest of the car, including the solenoid in the transmission... So if there was less power available to apply pressure to the traction plates at high RPM, this could be part of the problem!!! And then I can stop getting the bloody codes too.

 

[hako]

Jazza21 - I'd still get the cat looked at as this can cause the problems you have with lack of revs/power. Do it yourself as it sounds like you may be talking to people who are interested only in relieving you of $$$.... or get the RACQ technical service section to give you an opinion as they are independant and are not out to take your money. Never trust someone who just states that something is "stuffed" after a cursory look and finally remember there is a sucker born every day - try not to be one yourself.

 

[spazworm]

yer that sounds exactly like what happened to my vn and the guys took out th cat converter saw it was crap and replaced it.

lol i just kept driving it before hand not knowing it was the cat converter till it wouldnt go any faster than 5km per hour... now its hard to keep under control with the new cat.