No power below 2000 RPM, aircooled VW motor

Desp · Post by **Desp** » Wed Feb 10, 2010 3:32 am

A bit baffled by this situation and I'm not sure where to start on troubleshooting this. I have the stock distributor curve for my vehicle and set a flat map for it. Sitting still revving the engine it revs nicely, no issues. While driving down the road, regardless of the gear (even first gear at a low speed) I'll be rolling around at about 1500 RPM and floor it, and the engine sputters and bogs down badly, has almost no power and wants to die. As soon as i reach 2000/2200 RPM it launches nicely. I tried advancing and retarding the ignition and nothing seemed to help. It almost seems like it's missing, but it doesn't do it at all when there is no load present. It also didn't do this with the stock distributor so I'm really not sure where to start.

NITROPIXIE · Post by **NITROPIXIE** » Wed Feb 10, 2010 8:54 am

How have you calibrated the load axis on your map? Do you have enough load axis so the megajolt can control the ignition curve at these low load areas??

How old are your ignition parts? If the engine is stuttering it can be a sign your coil pack, leads or plugs are on there way out?? If you have a spares try changing them. I had something similar on mine which gradually got worse without changing anything.

Desp · Post by **Desp** » Wed Feb 10, 2010 1:43 pm

Below are my current ignition and the stock curve, right now it doesn't change any between load and no load. I originally had it with less advance under load then increased it trying to resolve the issue. Like I said it works fine at 2000+ RPM.

The coil pack and wires are from ebay, they were out of a junked car and reported to have been tested and working. The coil seems pretty strong as I accidentally unplugged one of the wires and the spark jumped about 4 inches to my hand. The motor stayed running during that which was pretty amusing. Just installed 4 new plugs, originally it didn't have R plugs in it, which I switched them out with. It didn't make any change at all.

The load is calculated through the MAP sensor

NITROPIXIE · Post by **NITROPIXIE** » Wed Feb 10, 2010 2:18 pm

Your load axis looks acceptable.

I don't think its a megajolt or edis problem. More than likely coil pack or leads since you have relatively new plugs. You can't really test the leads and coil packs with a traditional multimeter as this doesn't put a load on to these components so is not really an adequate test. Ideally these components are better off bought new in order to have a reliable setup.

What i would do now is a confidence check that the edis and megajolt are working correctly by using a timing light and observing the timing is moving as to what is displayed on the configurator screen above the 2000rpm where the problem is least noticable.

Another good sign that ignition components have failed is that it can sound a bit like a diesel.

DannyP · Post by **DannyP** » Wed Feb 10, 2010 10:56 pm

Nitro is probably right. I would replace the coilpack and wires. I don't use resistor plugs, but I have no accessories, not even a radio. Lights, wipers, ignition switch, that's it! NGK DP8EA9 in mine.

There is also a possibility that your VR sensor bracket is vibrating/resonating at certain rpms, and then clears up after 2200.

Those curves look good, but I wouldn't use more than 32 degrees from 70% to Full load above 3000 rpm. They really can't handle that much at full load, AFAIK.

Desp · Post by **Desp** » Thu Feb 11, 2010 5:47 am

Thanks for the suggestion guys, I'll try that as soon as it stops snowing.

As far as the coil packs go, would you recommend the accel ones, or are they crap? Also is there a way to switch over the wires to normal spark plug wires?

NITROPIXIE · Post by **NITROPIXIE** » Thu Feb 11, 2010 8:29 am

I believe them to be no more or less reliable than other coil packs, plus the edis is programmed to give the correct amount of dwell for the specifications of the coil pack, so ideally is best to stick with this type of coil pack.

As for ignition leads there are kits to make your own, people who fab them up to your specs, and even some std OE ones if you hunt around enough. There are also 2 types of OE coil packs, 1st gen and 2nd gen with different style lead to coil pack connectors. Its a matter of finding the correct setup you want and at the right price. Generally if you can find some OE leads with the correct style connectors it can certainly make life easier in the long run.

DannyP · Post by **DannyP** » Fri Feb 12, 2010 2:15 am

I have had only the Accel for two years, works great. Desp, location? In US, get wires for a 1990 or so Ford Escort. Add airseals and they go right on, as long as you have the threaded ends on the plugs covered with those metal nipple type ends. Plug length is OK also, but I guess it depends on where you put the coil, doesn't it?