Lack Of Power

[Pie 0]

Right, I have a 1991 1.6 CTi.

When I got it, it had starting / idle problems but WOT was fine.

 

Slowly been fixing things on it and have finally got it starting and idling well.

Changed then vacuum advance, fuel pump and filter. Adjusted the TPS and throttle body. Tested TPS, AFM, Coolant temp sensor, SAD all working fine.

 

Now, it idles fine, but just seems really gutless. After fixing everything, if you put it in neutral and put the foot to the floor, it would take forever to get up to even 4k revs and was really! slow. (this was mainly after putting a new vac advance on)

 

Now I have advanced the dizzy (turned it clockwise whilst stood on passenger side) as far as it will go, the throttle is a lot more responsive but driving it, it still just doesn't seem as quick as it should be. The more I advanced the dizzy, the more power I got, and also the higher the idle would get ( is this normal?).

 

Any idea where the power has gone? And is it normal that the dizzy has to be fully advanced to get any power? Could the dizzy be faulty/worn?

 

Thanks in advance

[davey sprocket 14]

If the problem started after you changed the vac unit and adjusting the timing improves things, I'd imagine that's where your problem lies.

It's a while since I changed my vac advance unit but if I remember correctly it was a faff to get the actuating arm to hook up to the mechanism in the distributor.

 

I wonder whether yours may not be quite on right and either pushing the timing way out or just locking it in a fixed position or something?

 

 

And yes, advancing the timing will increase the engine speed up to a certain point where it will drop off again, at which point you need to back the timing off a bit.

[Pie 0]

The world of timing is all new to me, so thanks for confirming that!

 

I thought it might be that, just wanted to confirm that it isn't likely to be anything I have overlooked. Been meaning to get the dizzy refurbed at h&h ignitions for a while now (only heard good things about them) so I think that could be on the cards soon. I think that will be the best option leaving it to the experts, then I can properly tick it off the list and hopefully spring the car back to life!

 

Thanks for quick reply mate, much appreciated.

[steve@cornwall 100]

has it always been gutless ? iff an improvemeent can be felt fully advancing the dizzy, and still it doesn't pink under load, that points to the cam timing being a tooth out. Imagine turning the cam that few degrees with the dizzy in place as it were .

[Tom Fenton 1,542]

I'd agree with Steve. If the timing is fully advanced and it isn't pinking then it points to the cam timing being wrong. You shouldn't be able to run it fully advanced on normal or super unleaded without it pinking. Ask Leetdave, in the last week we have transformed his 1600 GTI from a nervous handling slug, to a good handling zippy car, just by correctly adjusting the tracking and timing.

[Pie 0]

Thanks for the input Steve and Tom.

 

I don't entirely know what pinking is, is it a knock from the engine? It isn't making any unusual sounds, misfires occasionally at high revs but other than that no odd noises and the dizzy is fully advanced.

 

OK, that sounds like it makes sense to me, doesn't sound too complicated. Going to have to read up on how to do that as I'm not sure though.. Or is it more complicated than it sounds and I should get someone else to do it? :/

 

Quite excited as this appears to be the last piece in the puzzle to getting it running sweet!

[Pie 0]

Oops forgot to mention, no it hasn't always been gutless, used to be great on WOT but a PITA at idle.

Now it's great at idle but sluggish at WOT :/

[steve@cornwall 100]

usually, get the crank and cam pulleys lined up into the position where they are locked by dowells (as Haynes) I usually mark the cam belt / pulley with a vertical line on the belt and down through the corresponding tooth on cam pulley and as a failsafe, a couple of teeth further along I mark 2 teeth and the belt the same way. Slacken the cam belt tensioner, slide the belt off. move the cam pulley one tooth, refit belt, retension and give it a try!

[Pie 0]

Doesn't sound too bad.. Looks like I'll be cracking the Haynes manual out sometime this week then! Is there any way of knowing which way to move the pulley? Or is it just trial and error? E.g if you move it and it's worse then you should move it two teeth the other way on the next attempt.

 

After I have moved the pulley, should I leave the dizzy fully advanced or put it somewhere in the middle?

[BlueBolt 156]

Judging by the movement you have made to the dizzy, put that back to somewhere in the middle, slightly closer to the other end though, and move the cam pulley the same way by a tooth...

In principal, that should bring you back to more or less where you were in terms of the dizzy timing!!

 

Always make sure you can crank it over by hand off the bottom pulley before you start it by key!!!

[Pie 0]

Thanks Chris, that makes sense I get it now.

 

Appreciate the patience guys, will post results when I get it done sometime in the next week or so!

[steve@cornwall 100]

Move the belt, as said, crank by hand - although 2 teeth out is safe and wont give you valve/piston contact - leave dizzy where it is for first trial... best to only touch one thing at a time Fully advanced and with the timing right it will pull better, but pink under load (you'll know it when it happens!) move the dizzy a few degrees back and try again, best is with reasonable accelleration uphill in a higher gear than you would usually use. When you move it a small amount and the pinking has gone, ignition timing is as near optimum as makes no odds! Turn cam anti-clockwise i think .... if you end up 2 teeth out it will start and run lumpy, poss backfire. Just return the engine to its original point, as evidenced by your previous belt / cam marks and put it a tooth the other way!

 

PS the cam marks can be invaluable as the cam movement will probably take the cam over its "rocking point" and can quickly turn more than one tooth away! You need to be able to easily return to where you started!

[welshpug 1,657]

got the dizzy on the right way up?