Need some advice

rsecrist · 07-21-1999, 11:13 AM

Having some problems.. Here's the scoop. I've got a '71 914. The head on the engine decided it wanted to crack so I dug up a 1.8 engine and had a friend of a friend do the swap. Was going to go with dual carbs - got some used, but the butterfiles in one didn't want to turn so as a band aid till I can get that problem sorted out, the mechanic just put the D-Jetronic FI onto this 1.8 engine. Now to the problem. When accelerating - if I apply too much pressure to the accelerator or try to get on it in the least, it sounds like the engine is choking (and actually starts to slow down). I have to speed up very slowly. This happens in all gears. Is this model FI completely incompatible with the 1.8? I know that the 1.8 originally had the L-type injectors.. Could it be a timing or ignition problem? Any suggestions?
Thanks -
Rob

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

If your mechanic used the whole D-jet system, it should work OK. Maybe not great, but at least OK.

I suggest starting the FI diagnostic, which means first of all checking out the ignition system. Check the spark, dwell, timing, and make sure that it advances and retards reasonably. While you're doing that, check the plugs to see if the engine is running rich or lean. (I'd personally guess rich.)

Check the fuel pressure. Check the valve adjustment. Then start checking the FI components. Kjell Nelin's D-jet guide on the 914 Fan Page http://www.914fan.net is an invaluable guide.

Good luck!

--DD

JP Noonan · 07-21-1999, 06:01 PM

Always check the ignition first. Sounds like it may be retarded. Also since it is a 1.8L with a D-Jet (BTW my friend's 75 1.8L had a 2.0L D-Jet on it and it worked fine for the PO, that is untill he ran it without oil) REALLY check the timing. Reason is that the 1.7L and 2.0L engines have timing marks sometimes at "0" usally at "5 degrees" and always at "27 degrees" (I've only seen one fan, from a 78 bus that had NO marks, it also didn't have a hole in the fan housing). The D-Jet is set to 27 degree BTDC (before top dead center) at 3500+ RPM. This is it's TOTAL advance.

The 1.8L L-Jet is set at 850 RPM (around idle) to 7.5 degrees. Both are done with the vac hoses pulled and plugged.

So if the tech timed the car as if it were a 1.7L he would have timed it for 7.5 degrees advance at 3500 RPM. Can you say "DOG"?

Try doing a "static timing", that is timing with a test light not a strope light.
Step 1: buy a Haynes 914 manual.
Step 2: follow the directions.
Seriously, you should get the book, there are too many picures far me to discribe.

Another way is to either put the 1.7L fan on the 1.8L motor (not too hard, about as hard as changing an altinator belt) or count 4 fan blades over from DTC (the 4th blade is right next to the thick fan support, again pictures would help imensly) this is about 23-25 degrees, probably better than where you are, but not too advance to get you in trouble.

Next test the dwell. Actually you MUST check the dwell FIRST. Any change in dwell changes the timing.

Finally make sure each plug is getting a fat spark and that they all look the same, if one is really clean compared to the others you have a dead cylinder.

For the FI, check that the thottle position sensor is plugged in.

halbl · 07-23-1999, 03:37 PM

JP, DAVE, I could use some advice on the same subject. What is the correct timing for a 2.0L with mild cam, 009 distributor and single progressive 32/36 carberator. Help solve an argument. Is it still 27 degrees BTDC at 3500????

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

Sorry. There *is* no "correct" timing for a carb set-up with a 009. This is an aftermarket distributor, whose only two virtues are that it fits, and it's cheap. It was not designed with the 914 motor in mind--in fact, I hear it was designed for "industrial" motors that ran things like electrical generators. One RPM only.

The 009 has something like half of the centrifugal advance built in as the stock distributor. So, you can set the static timing (0 RPM) and be able to go reasonably right off idle. But the poor motor will run out of steam in the middle of the RPM range. OR you can set the all-in advance (3500 RPM) and have a motor that pulls well up top. But it will bog HORRIBLY off idle. But you can't get both at the same time unless you re-curve the distributor.

You can also try a compromise. You pretty much just have to try it and see how it feels.

--DD

[This message has been edited by Dave_Darling (edited 07-23-1999).]

JP Noonan · 07-23-1999, 10:35 PM

Thing about these motors is they perform better the more advance you put in, unfortunatly the also detonate the more advance you put in. So be careful about how far you go.

Don't know about the 009, but in Tom Wilson's book he says that to cure the Type-I's #3 cylinder overheating problem they retarded #3 on the dizzy. Talk about a band-aid fix.

Check out some of the VW mags they talk about tunning the 32/36 carb to get rid of the "flat spot" most of them have. Also how to time it. As for the dizzy, try to find a vac adance unit from a 1.8L I've heard they are the best way to go with a carb.