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View Full Version : 1994 Passat 2.0 16v - Lack of power



oldboy
01-09-2007, 10:35 AM
I have recently bought this car, it lacks power on acceleration, particulary at low revs.
It has covered 163K miles but sounds good and drives well. My last car had the 2.0L 8V engine which had much better accelleration at 150K miles.
Is there something that wears causing loss of power?
I have checked for air leaks and for faults using VAGCOM.
Any suggestions?

scotty33
02-09-2007, 08:47 PM
This really depends, on how 'flat' it is. 16v engines by nature, are known for being a bit gutless at low revs, they make up for it above 3500rpm!
Is it a 9A or ABF engine code?
I would suggest a knock sensor, or Mass Air Flow sensor, could be faulty, but you say VAG - com returned no faults.. Ignition Timing could also be out?

oldboy
02-09-2007, 11:35 PM
Thanks for your help Scotty
The engine code is ABF
Gutless is the right word for the low revs performance
Its a bit better above 3500 but still disappointing.
Is it possible to check the knock, mass flow sensor or ignition timing?
Feels like not enough fuel at low revs.Could it be fuel pressure? do fuel pumps wear out or do pressure regulators fail?
:confused:

a8 tech
02-09-2007, 11:40 PM
fuel filters clog up as they were designed for the life of the car but its advisable to change it or check fuel pressure at 2500rpm(2.5 bar ish)knock sensor would store fault code and timing is worth checking as the belts have a lot of slack but uneven idle/starting would be more noticeable.

scotty33
04-09-2007, 12:44 AM
As there are no fault codes, you could look at the basics first. Is the compression ok? are the plugs' colour ok and even?
I'm not sure what the set up procedure is for the ABF ignition timing. You could mark the distributor position as is, then experiment with various adjustments either way, if it improves, get it setup properly?
The valve timing could be out.
I'm dubious about the fuel supply being bad. If there is enough to make it pull higher revs, then there should be plenty for low revs? If this is not the case, try a filter and pressure test as A8 tech suggested.
The engine is the same as used in mk3 golf 16v, among others, you might get more info on a mk3 golf forum?

Crasher
04-09-2007, 01:00 AM
Go into measuring blocks 08, display group 02 and look at the voltage figure in zone 3 and see if it is around battery voltage (confirm this with a multimeter on the battery) and not fluctuating wildly or even reading something silly like 18v or as low as 4v. If the figure is off, replace the ECU relay at position 3 on the fuse box, the one with 30 on top. The VW number is 165 906 381 and they cost about 14.

tatham
13-11-2007, 01:30 PM
If the figure is off, replace the ECU relay at position 3 on the fuse box, the one with 30 on top. The VW number is 165 906 381 and they cost about 14.

Hi
Thought I'd mention that I had a similar problem (at mid range revs though) and went to 3 garages without finding a solution.
Finally solved by Crasher on another forum (the same person, I presume?). Replaced my ECU relay, which cost about 11, and it's being going really well ever since!

Crasher
13-11-2007, 02:22 PM
I do get around a bit http://smileys.smileycentral.com/cat/4/4_18_7.gif (http://www.smileycentral.com/?partner=ZSzeb001_ZNxdm824YYGB)





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aris
12-12-2007, 04:25 PM
I have this problem on an 8v MK3 GOLF GTI (1997).

I tried replacing the ECU relay - this did not help.

I took it into the garage, and the diags said the lambda was out - so we replaced this - along with the rotor arm, cap (they were looking a bit cracked - they needed replacing anyhow), and also a temperature sensor.

No joy - same problem. Here are my exact symptoms:

Car feels a bit flat, but when I get to about 3000 RPM, the car stutters quite badly. If I lay off the accelerator and accelerate gently then it is a bit better. It is also a fair bit better if I put the accelerator down to the floor when accelerating. Could it be a fuel issue?

The ECU relay I changed is not a VW one - but an aftermarket one - could this be making the difference? Changing this relay really did make no difference.

I've had this problem for over a year - and intially I changed the plugs and leads, and air-filter. No joy there either.

I don't want to go putting good money after bad and changing everything in sight.

Any ideas?

Thanks,

Aris

Crasher
12-12-2007, 05:39 PM
Have you had it read for codes again recenetly?

aris
12-12-2007, 07:02 PM
I'll reply here: http://www.vwaudiforum.co.uk/forum/showthread.php?t=21697