1.0L Polo losing power under heavy acceleration

david burton · Post by **david burton** » Wed Aug 06, 2003 2:37 pm

I have a MKIV 1998 (Mk 3 to some) 1.0L Polo that is losing power (it does have some power, honest!) under hard acceleration.

If I'm gentle on the throttle then it's fine and is actually quite perky to drive, and I can actually accelerate quicker than if I really hammer the throttle. Can't figure out what's going wrong - maybe I need new sparks but should I just take it to VW for them to check out the ECU? It seems to keep constant power instead of picking up at about 3500rpm. It's searching a little bit at idle but not much.

Any ideas?

Cheers

Dave

polo2k · Post by **polo2k** » Wed Aug 06, 2003 2:42 pm

ok firstly id clean the throttle body then get the air flow sensor and the lamba sensor checked out by vw, other that that maybe run some injector cleaner and change the plugs and leads

Speedlaw · Post by **Speedlaw** » Wed Aug 06, 2003 5:38 pm

Perhaps a silly suggestion, but can a filthy air filter have an influence on this?

[Btw; David: Welcome!]

david burton · Post by **david burton** » Thu Aug 07, 2003 2:31 pm

Changed the plugs last night which seems to have mostly cured it... I say "mostly" because it was 100% ok and then spluttered a wee bit after deceleration. The plugs were visably worn so it definitely needed doing!

These polo engines are pretty torquey for their size... I have just been offered a 2001 reg black 3 door 1.4 (75bhp and 19k miles) polo for Â£5950... Very tempted!

Cheers for the replies.

Dave

(watch this space, may post some pics of my bird's modded mkiv with some pretty unique Hella rear lights - LED ones, none of this common lexus stuff

you can get em from www.airspeedshop.co.uk)

Speedlaw · Post by **Speedlaw** » Thu Aug 07, 2003 2:46 pm

David,

If she has a Polo too, invite her this way!

Torque is nice btw, makes for excellent drivability, albeit with low Hp figures.

david burton · Post by **david burton** » Fri Aug 22, 2003 3:34 pm

Alex - I like the grill. very clean car. is it hand made?

The problem with my car has come back, I have run injector cleaner through it and changed the plugs. No luck. It seems to be struggling for either fuel or air. I am planning on changing the air filter this weekend and finding out where the fuel filter hides to do that (any hints?! - i've only has the car a month so haven't had time to explore). then it'll be a trip to vw.

Impressed with the little car's economy too - have done a 200 mile 4400rpm (80mph) run and 160 miles thrashy town driving and got 41mpg from it. the new plugs helped tho

. the polo is earning a place in my heart!

Chat to y'all later

Dave

P.S. got a 50mm lowering kit booked in for next week, and some 14" alloys to set it off. no point in spending a fortune - it's only a 1litre

P.P.S Anybody catch the conversation on performance vw magazine's forum about the chap who wanted to get 80bhp out of his 1litre polo? It was very amusing. all hell broke loose!

Speedlaw · Post by **Speedlaw** » Fri Aug 22, 2003 3:51 pm

Thanks David! The grill is made by FK Automotive (or at least, they sold it to me). Pops straight in.

I'm ashamed to say that I wouldn't know where the fuel filter is...

...but both air and fuel filter could be a prime suspect.

I didn't see that discussion on the 80hp 1 litre by the way - but now I'm curious!

Don't forget to take some pics after you've fitted the wheels and suspension!

david burton · Post by **david burton** » Tue Aug 26, 2003 12:08 am

The argument was actually last year:

http://www.performancevwmag.com/forum/t ... IC_ID=6535

I didn't realise it was so old! Very funny tho.

Cleaned the throttle body ehich seems to have helped. Cheers for the advice polo2k.

I will take some pictures before / after the lowering and also when I get these wheels. can't wait!

Dave

KarlM · Post by **KarlM** » Tue Aug 26, 2003 9:11 pm

how funny is that post!

reminds me of the turbo v6 9n we had on here once!

Post by **mole** » Fri Aug 29, 2003 1:07 pm

haha @ Karl!

toXXin · Post by **toXXin** » Fri Aug 29, 2003 3:08 pm

Anyone I know?

dubpolo · Post by **dubpolo** » Tue Dec 16, 2003 9:48 pm

hi i have the same problem!! but ive had the spark plugs, ht leads, dissie cap and rotor arm changed. i booked it into VW like you said and all they came back with was the temp sensor which has now been changed. how do you clean your Throttle body? is there any seals that will need to be changed after removing?

david burton · Post by **david burton** » Tue Dec 16, 2003 10:31 pm

hello!

never got it fixed - cleaned the throttle body and did the filters and plugs but haven't had time to take it to vw. I take it your VW dealers came up with the temp sensor as an error code on your ecu? Did it help?

cleaning the throttle body will always help. Take the air filter off and you'll see the inlet chamber. spray some throttle body cleaner into it both when the engine is off and on (when it's off, open the butterfly valve fully and blast if clean of debris and carbon). It'll run funny for a few miles, but should adjust itself soon enough.

you might want to reset the ecu too - disconnect the battery for half an hour, turn the ignition with it disconnected a few times, then reconnect.

let me know how you get on!

Tahrey1043 · Post by **Tahrey1043** » Fri Jan 09, 2004 8:18 pm

Now, yknow, I don't think it's that unlikely. Stick a decent filter and intake on, fresh exhaust, a chip and get a performance cam for a 1.3 (seeing as they're the same head, just a taller block... aren't they?) and...... a G-Lader

preferably a 60 if you can make it fit.

Look at the performance difference between the GT and the G40... and what are the differences between them... a supercharger and a few other simple parts. 75hp going up to 115hp... and that's for an untweaked G40 to boot.

Now if you work that out in equivalent fashion, then heck.. i could get almost 70 horse out of my Spi 1043cc'er, which isn't bad at all, especially considering the equivalent torque increase would actually let me whip a GT thru to about 90mph... If theirs is a 50 or 55hp modern MPi 1-litre it could easily reach 80 (or, if you managed to kludge an injector head fitting onto the 1-litre block - 75hp from a previous 55hp remember, though the torque stays the same) and start looking towards 90. Probably be far more worth my while getting hold of the power unit and gears out of a stock Toyota Yaris VVTi (999cc, 70bhp) and figuring a way to mount it and tweak THAT however.
Add some NOS for extra torque, and whahey...

And it stays a 1 litre for insurance reasons (and the cc even goes down with the second option). However I think they might get pissy if they find out you've added 50% onto the cars power and a number of performance components without "consulting" them first so they can "revise" the premium.

(( Of course, a very interesting subject to me all round, what with being "stuck" in a 1L with 3 and a half cylinders right now ))

david burton · Post by **david burton** » Fri Jan 09, 2004 11:22 pm

ok with a turbo I think you'd be there - or a supercharger. But the point I think everyone was making is that insurance would be cheaper for a g40... I don't think an insurer would take too kindly to a supercharged 1 litre!

3 and a half cylinders?

You want a mint 1 litre polo? I'm test driving a 16v tomorrow... I'm in brum too...

laters