Suggestions

[chunder]

Guys had that nightmare of nightmares today, out my recently acquired 306GTI 6 on the rollers to have a look see.
No mods so is standard, flywheel power should be 167, I got138.
Now car has done 90,000 miles so would expect some drop off but not 30 Hps.
Car pulls well and is fuelling well. But I can't really compare it to anything!
Doesn't miss or appear to do anything dodgy, but surely that much would mean a problem like an injector block or something more serious rather than simply a fuel issue or dodgy mods fit net.
Am a little perplexed and not sure how to play it.

[MGDavid]

combustion is everything - have you had the injectors cleaned and checked the spray pattern, need mist not droplets.

[chunder]

Yes indeed I think a compression check first to see if there isn't a horror show, then if that's ok injectors cleaned.
Worst nightmare though, horrible!

[GORDON STREETER]

Also you can't get an accurate flywheel HP reading off of a rolling road, you can only compare it to another GTI on the same day to get a better idea of how good (or bad) it is, unless the RR operator has good previous experience of one particular type of car I wouldn't worry too much

[chunder]

I know gordon, but a mate got a goid reading thete from a van, hardly normal roller fare
So i am fairly sure something is amiss, especially when on forums etc there are loads of similar mmilage versions getting good figures.
I dont know really, wont hurt to do a compression check and clean injectors maybe, anything worsr and its scrap, but it dont burn oil or use it so cant be anything hotrrendous

[FastDB2s]

Is the cam timing accurate, if its had a head skim it may not be correct but retarded, K series suffer from this.

[chunder]

I am thinking this might also be the issue, after doing some research on various 306 forums.

[FastDB2s]

One of the mods the K series Clubmans racers do is skim the head but they are not allowed to fit vernier cam wheels so this retards the cam timing which actually costs power, many engines are also affected by this.
Its best to find out correct cam timing as lift at TDC, not always easy but then use a vernier cam wheel to correct the timing, or take the engine out & plot the max opening point in terms of degrees & do it that way then make a note of the valve lift at TDC as a refernece.

[Lancsbreaker]

Originally Posted by chunder

I know gordon, but a mate got a goid reading thete from a van, hardly normal roller fare
So i am fairly sure something is amiss, especially when on forums etc there are loads of similar mmilage versions getting good figures.
I dont know really, wont hurt to do a compression check and clean injectors maybe, anything worsr and its scrap, but it dont burn oil or use it so cant be anything hotrrendous

Gordon's right, you have to compare apples with apples.....it doesn't matter what people got on other RRs, only what a theoretically identical car gets on the same RR, on the same day with similar weather conditions.

[GORDON STREETER]

I will always remember a guy that brought a V8 Rover to me years ago because he said that it didn't go "quite right".
This car had been on the same rolling road twice for the problem and couldn't fix it, as soon as he turned up with it I said "by the sound of it it's going on 6 cylinders" a quick look under the bonnet showed 2 plug leads on wrong !!!!
I have to say that particular rolling road went out of business pretty quick

[FastDB2s]

Have you found out what's wrong yet