2056 advice needed

Pritchard · 04-05-2002, 06:10 PM

I just finished the conversion from 2.0 L to 2056 cc. To my surprise, the engine fired right up. I remembered to connect everything. That was a miracle in itself.

Now that I have the car roadworthy again, I have a question for those who have done this conversion and retained the stock D-Jet FI. What adjustments have to be made to the FI system for the increase in displacement? I have done the following: bumped the fuel pressure to 31psi, adjusted the MPS to run a little richer, adjusted the ECU idle knob for richer... Is there something else that I should do? I plan on taking it to a nearby garage to put it on the "sniffer" to really get the MPS dialed in correctly.

Also, for those that have done this, did the car "feel" different at idle? Mine idles a little like its mad at me. It kinda "grumbles." The idle is mostly smooth but just different. Very hard to put into words. BTW, the compression ratio is up to 8.4. Maybe that's the difference I'm feeling.

For those thinking about this mild upgrade, I can definately feel the difference when accelerating. It won't lift the front wheels off the ground, but there is a noticable improvement.

Thanks for any input.

David Pritchard

Bleyseng · Bleyseng's Garage

I have basically the same motor and I recommend taking the car to a dyno shop to dial in the MPS. You want to get a reading on what the fuel mix is in partload and WOT. It should be set to about 13.7 to 1 at partload and 12.8 at WOT. Do several runs adjusting the MPS in between to get it right. After you are all done you must set the full load stop. Otherwise if you adjust the full load and not the stop you will break the diaphram inside.
Once you get it adjusted the car really does have more power plus you can see on the dyno sheets how much!
I assume ALL the other FI parts are in good shape, no air leaks, and the dist is in excellent condition, timing set.
Geoff

r_towle · 04-18-2002, 03:47 PM

If you find that you are running to lean, look for the Bosch injectors for the 2.5 liter Mercedes from the 70's.

The injection system basically tells the injector how long to stay open...to increase fuel to the cylinder you will need a larger hole in the injector, ala larger injectors.

Sorry I do not remember the part number, but 2.5 liter gas mid 70's mercedes

Rich

Pritchard · 04-18-2002, 05:03 PM

I still haven't taken the car to get the exhaust sniffed. I have had a lot of idle trouble. READ...I couldn't drive the car

I took out the Pertronix Ignitor to reinstall the points, but the ground strap between the two plates was broken. BTW, how do you solder to the plates in the dizzy? I have been soldering stuff for over 20 years and could not get the solder to stick. I'm at a loss.
Anyway, reinstalled the pertronix, reset the timing, and now a perfect idle. I have no idea what variables got changed, but it idles perfectly now.

I used to have a Volvo wagon with a similar FI system. It was a 2.3L four-banger. I was thinking that the injectors from this engine might work. I don't think I'll need to change the injectors, but someone may.

Any thoughts?

David Pritchard

Jim Smolka · 04-18-2002, 06:26 PM

To solder the braided wire of a dizzy, simply go to your local Radio Shack and purchase copper de-solder wick, solder and some flux. Cut about a 1.25 inch piece of the wick. Hold the wick with a pair of neddle nose pliers about 1/4" from one end. Then, apply some flux and heat the wick with a solder gun and tin the end of the wick. Repeat the process for the other end. The trick is to tin the ends of the wick, not the middle of the wick.

If the wick is completely gone from the dizzy, you might need a bigger solder gun and a bunch of flux. However, I have always been lucky since a piece of the old ground was still left.
Tin the dizzy plates. Then solder the tinned wick into place. Again the trick is to use the needle nose pliers as to act as a heat sink to prevent the middle of the wick from absorbing the solder.

Pritchard · 04-18-2002, 06:37 PM

The ground wire(braid) is completely gone. I guess I'm not using enough flux. I know what you mean about keeping the solder out of the middle of the wire. I wasn't thinking last nite and let the solder run way too far up the wire. Not very flexible. I might try again, but the pertronix is working fine right now.

Thanks

David Pritchard

red-beard · red-beard's Garage

Use needle nose vise grips for your heat sinks

James

Jim Smolka · 02:32 AM

To keep the solder from traveling to far up the wick, use a piece of a cotton ball around the jaws of the needle nose pliers. Then soak the tips of the pliers in water. As the wick gets hot, the water will prevent the solder from going past the pliers.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

If the ground braid is broken, the plate has seen a lot of use. Why not replace it?? There's a VW part number, I think a Type III part, that drops right in. I don't have the part number here, and I won't have access to my files until next week. Kap'n Krusty over on the Rennlist has sent the part number to the list a few times...

--DD

Bleyseng · Bleyseng's Garage

I didn't have any problems getting the A/F mix right by adjusting the MPS and bumping the fuel pressure up to 32 lbs. It is a little bit tricky but if you read Paul.B Anders page carefully you can do it all at the dyno shop. The trick is reseting the full load stop but that can be done later on the bench at home.
I don't see any need to swap out the injectors for the MB ones as the 2.0l ones flow enough fuel.
Geoff

HarveyH · 04-19-2002, 04:48 PM

I don't think the Pertronix unit requires a ground through the breaker plate. The unit I installed appeared to be a completely epoxy encased piece, with no exposed metal for a ground point. The two leads from the sensor that pass out of the distributor to make the required connections.
Harvey

Pritchard · 04-20-2002, 01:40 PM

HarveyH- you are right about the Pertronix not needing the ground wire in the dizzy. I was just fiddling around with it to try and use the points again suspecting a possible Pertronix unit gone bad. All is well with the motor as of 30 minutes ago. It might idle fine the next time I crank her up, or she'll be pissed at me for something and not idle worth a flip. I am still at a loss.
With this particular episode today, the motor was running rich at idle, so I backed off the potentiometer that I have in-line with the CHT to correct the idle problems. Some days I have to increase the richness to get it to idle correctly. It sounds like a vacuum leak, but I can't find one anywhere. I have even risked what little hair I have left and sprayed starting fluid all around the hose connections to no avail.
Having read Brad's webpage, I am thinking that the throttle position switch is not causing the idle circuit to engage all the time. Is this a possibility?

Keep the ideas coming. I need all the help I can get!

Thanks

David Pritchard

Pritchard · 04-21-2002, 06:27 PM

For those who have been keeping up on my idle problems, I may have found the problem.

On a hunch, I took the cover off the ECU to check the potentiometer that helps with the fuel mixture at idle. It was only registering at 100 ohms. So I turned the knob on the top of the ECU and no change. I pulled the pot. out and found that the thing was siezed at its leanest position. The knob was just spinning on the shaft and not turning the pot. With a little coersion and machine oil, it is now turning freely. The range of the pot is from about 100 ohms to just over 6000 ohms. This lack of input for the ECU explains a lot of my problems. I checked every wire in the ECU harness for continuity and reinstalled everything. The motor will now idle almost perfectly.

I say almost because when the lights are turned on, the idle drops to about 500 RPM. That's for another day.

Thanks to all who have given advice, it is greatly appreciated.

David Pritchard