I converted to a point-less ignition module some months ago, and up until recently had no problems with the engine. A month ago or so I was driving and had the car heated up pretty well, when it started to have problems at low RPMs. The tack started going nuts, and unless I had the engine at high rpms it would stall out. This only happened when the engine got hot. My daily commute is nor more than 10 minutes each way so it wasn't really much of an issue.

So I took off the cap and things looked funny inside. The part that the rotor rubs against at the middle of te cap was worn pretty good for being only a few months old. It also looked like the rotor was striking the contacts at their tops. My thought was that the little disk with magnets for electronic ignition module was causing the rotor to stick up too high and when the car got hot, the shaft of the distributor got a little longer and passed the threshold of working. so I sanded down some of the base of the rotor and put it back in. It seemed to help a bit.

The next problem I fixed was a leaking fuel line which I caught very quickly. Ignition was still not working great however until I pulled out the rotor and wiggled it back in a little better.

Today on the way to the dentist (a bit farther than the car usually goes) another weird thing started happening. If I didn't hold the throttle open a bit the engine would idle on 1 or 2 cylinders for a few beats and then die. Occacional backfires too. So I'm still thinking its an ignition problem...
The tach would drop very quickly to 0, unless I had my foot on the pedal. Does this sound like a TPS problem maybe????

The engine runs very well except when it is allowed to die. Its not missing, etc. Just struck me as odd that it would behave the way it is.

My current plan is to get a new ignition module, maybe a pertronix, and install it to see if that helps it. Any other suggestions?

-Tony

Replace the cap and rotor, once they get messed up they stay that way.

Tony, did you fix the exposed wire on the points module?

QUOTE (bondo @ Jul 13 2005, 01:30 PM)

Replace the cap and rotor, once they get messed up they stay that way.

Darn! I was hoping that by continuing to use them, they would fix themselves.


Andrew

You guys are all Electrical Engineers.....

looks like you need an ME to solve this one

QUOTE (Aaron Cox @ Jul 13 2005, 02:38 PM)

You guys are all Electrical Engineers..... looks like you need an ME to solve this one

What did you just call me??!?!

I'm a.. um.. a... hmm.

QUOTE (Aaron Cox @ Jul 13 2005, 01:38 PM)

You guys are all Electrical Engineers..... looks like you need an ME to solve this one

Please don't insult Bondo!


Andrew

his post snuck in when i was typing......

royce is an architect right? he can make it work on paper then...

QUOTE (jkeyzer @ Jul 13 2005, 01:34 PM)

Tony, did you fix the exposed wire on the points module?

He never got a round tuit. He was too busy trying to get Euro lenses for me and bondo.

Andrew

QUOTE (Aaron Cox @ Jul 13 2005, 02:43 PM)

his post snuck in when i was typing...... royce is an architect right? he can make it work on paper then...

I have a degree in architecture, but I don't think I'd like being one that much. Besides, I can't find an architecture job here. For the time being I am working half time at Cal Poly as a technician, and fill in working at Go Westy (a vanagon place). I don't know what I want to be when I grow up.

QUOTE

He never got a round tuit. He was too busy trying to get Euro lenses for me and bondo. Andrew

yeah! I was trying to get euro lenses for you guys from that dude. That dude is a weird guy. He has all this stuff he wanted to sell, took FOREVER to get me a list of stuff, and then when I told him what we wanted by email and by voice mail he never got back to me. Very weird. But at least I managed to get a good roller out of him for a good price.

QUOTE

You guys are all Electrical Engineers.....   looks like you need an ME to solve this one

ya ya ya. It is funny though that Mr. Architect has the only useful advice.

I guess us Lectrucul Engunears are just good for nuthins.

Or "sparkys" as the MEs call us here.

-Tony

Back to answers...........whether related or not, I have exactly the same thing and it drove me crazy. I broke down and took it to a local guru. First, the replacement of cap etc., then the replacement of the MPS. I got an old one from a type 4 VW and had it calibrated by Jeff Bowlsby in San Jose. The problem was that I forgot I had a big bore kit and hydraulic valves in the car. It took some fooling around at the gurus and riching up the mix but runs really strong now. I understand that the MPS thing is fairly common at the advanced age.

fadler15222
San Diego

Damn. I hope its not an MPS. I really need to get this Subaru conversion on my other car done so I don't have to fool around with this crap anymore. Of course having to fool around with this crap is whats keeping me from finishing.

I think I'll first try the cap and rotor, and then see about a new ignitition module. After that I'll try another MPS.

-Tony

Ever thought about cleaning up your vacuum lines and those bad electrical connections?

It always helps to start with the basics.

When's the last time you checked your spark plugs?

Also don't rule out the fuel injection trigger points after you have checked everything else.

Did you know that Pelican has a d-jet tester they will let you use if you ask nicely enough?

So on the way home from work today I stopped by Pep Boys and grabbed a new cap and rotor. The old one was worn and had carbon deposits all over the inside, probably because the rotor sat too high on the distributor shaft. I sanded the base of the new one down 50 mils and it made plenty of clearance on the bottom for the magnet disk.

Tonight I took the car out for a spin and 15 minutes into it, the problem came back. came to a stop light, the engine felt like it was running on 1 or 2 cylinders, the generator light flashed in unison, and the engine died and the oil light came on. Started it back up and stumbled home with a single good and loud backfire.

When I replaced some fuel lines recently I checked the vacuum lines to make sure everything was fine, so I think they are okay and all in place.

Something that struck me odd is how the problem is almost digitally heat related. Beyond some temperature the problems are there, below it they are completely non-existent and the car runs perfectly. I'm wondering now if maybe my CHT is acting funny. I suppose tomorrow I'll measure the resistance and drive a bit and measure it again. To rule out the ignition I could drive around with my oscilliscope hooked up to the coil input to verify I'm not dropping fire pulses.

How's that for EE jargon Aaron?

-Tony

Tony,

Why don't you just buy another 914? I know of one that will be for sale soon. You are very familiar with it. You can make payments.



Andrew

QUOTE

Why don't you just buy another 914? I know of one that will be for sale soon. You are very familiar with it.  You can make payments.

I am thinking that I'm getting tired of type IV engines...

hmmm. I think what I should do is sell my daily driver and use the time I will ahve to finish my conversion. But that would put me 914less for a few months!!!! Oh the horror!

-Tony

QUOTE (TonyAKAVW @ Jul 14 2005, 09:45 AM)

QUOTE Why don't you just buy another 914? I know of one that will be for sale soon. You are very familiar with it.  You can make payments. I am thinking that I'm getting tired of type IV engines... hmmm. I think what I should do is sell my daily driver and use the time I will ahve to finish my conversion. But that would put me 914less for a few months!!!! Oh the horror! -Tony

Oh well, I guess if you don't buy it, I will have to cut it up. I tried.

This will be your fault. I hope you can live with yourself.


Andrew

QUOTE (phantom914 @ Jul 14 2005, 10:53 AM)

QUOTE (TonyAKAVW @ Jul 14 2005, 09:45 AM) QUOTE Why don't you just buy another 914? I know of one that will be for sale soon. You are very familiar with it.  You can make payments. I am thinking that I'm getting tired of type IV engines... hmmm. I think what I should do is sell my daily driver and use the time I will ahve to finish my conversion. But that would put me 914less for a few months!!!! Oh the horror! -Tony Oh well, I guess if you don't buy it, I will have to cut it up. I tried. This will be your fault. I hope you can live with yourself. Andrew

Dibs on the bumpers!

QUOTE (TonyAKAVW @ Jul 14 2005, 10:45 AM)

QUOTE Why don't you just buy another 914? I know of one that will be for sale soon. You are very familiar with it.  You can make payments. I am thinking that I'm getting tired of type IV engines... hmmm. I think what I should do is sell my daily driver and use the time I will ahve to finish my conversion. But that would put me 914less for a few months!!!! Oh the horror! -Tony

I'm going to be 914-less for alot longer than that! Better get a radiator for your truck first though!

I'll buy your yellow one for what you paid, even though it's broken now... What a deal!

QUOTE (bondo @ Jul 14 2005, 10:25 AM)

Dibs on the bumpers!

Andrew

QUOTE (bondo @ Jul 14 2005, 10:27 AM)

I'm going to be 914-less for alot longer than that! Better get a radiator for your truck first though! I'll buy your yellow one for what you paid, even though it's broken now... What a deal!

Why can't he just use the radiator from the yellow car to fix the truck?

Andrew

QUOTE (phantom914 @ Jul 14 2005, 11:47 AM)

QUOTE (bondo @ Jul 14 2005, 10:27 AM) I'm going to be 914-less for alot longer than that! Better get a radiator for your truck first though!   I'll buy your yellow one for what you paid, even though it's broken now... What a deal! Why can't he just use the radiator from the yellow car to fix the truck? Andrew

Hehehe, I have suggested he put a type IV in the truck.. he even had a spare for a while.

My car had the same symptoms.
Sure enough - when it would momentarily short out it would cause the tach to
go crazy & the engine to backfire and even quit. I traced it to the wire from the tach to the coil. I spliced in a new wire and soldered the terminal end.
Problem B gone.
30year old wires = brittle wire insulation = PITA.