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Posted by: luskesq Oct 24 2010, 06:40 PM

Have a '70 1.7 that I picked up that hasn't been run in years. Gone through ignition, points, plugs, timing and it runs . . . badly. Discovered when running that I can pull the ignition wires to 1 & 2 and it runs the same. No injector clicking with key on and opening the throttle switch on 1 or 2. 3 & 4 click. Could the problem be the trigger points and do all stock 1070 1.7's have trigger points?

Posted by: swl Oct 24 2010, 07:39 PM

I think that 1&2 failing is indeed half of the trigger points. Quick way to check is to reverse the plug on the dizzy. If the fault travels to 3 and 4 you have your culprit. Be very careful when you pull the plug. Very easy to break wires.

Posted by: brp986s Oct 24 2010, 07:39 PM

All stock 1.7 have the trigger points in the distributor. The way to test them is have someone turn over the engine while you measure continuity between the center and either of the the outer pins of the distributor. The circuit should open and close once per rev of the distributor rotor. One side of the trigger will fire injectors 1 & 4, the other 2 & 3. As the triggers wear, the slider blocks wear out - the circuit fails to open, and the ecu doesn't receive the signal to fire the injectors.The function of the trigger points is unrelated to the tps. good luck.

Posted by: ejm Oct 24 2010, 07:45 PM

Sounds more like a problem with the injector grounds. They are paired left and right. Check the three ground connections on the top of the engine case under the intake plenum.

Posted by: Jeff Bowlsby Oct 24 2010, 08:20 PM

Posted by: Cap'n Krusty Oct 24 2010, 08:29 PM

QUOTE(swl @ Oct 24 2010, 06:39 PM)

I think that 1&2 failing is indeed half of the trigger points. Quick way to check is to reverse the plug on the dizzy. If the fault travels to 3 and 4 you have your culprit. Be very careful when you pull the plug. Very easy to break wires.

No way. The Cap'n

Posted by: luskesq Oct 24 2010, 08:53 PM

QUOTE(brp986s @ Oct 24 2010, 06:39 PM)

All stock 1.7 have the trigger points in the distributor. The way to test them is have someone turn over the engine while you measure continuity between the center and either of the the outer pins of the distributor. The circuit should open and close once per rev of the distributor rotor. One side of the trigger will fire injectors 1 & 4, the other 2 & 3. As the triggers wear, the slider blocks wear out - the circuit fails to open, and the ecu doesn't receive the signal to fire the injectors.The function of the trigger points is unrelated to the tps. good luck.

Thank you all for the input. The ground connections are in place but I'll double check the quality of the connections. STUPID QUESTION??? Are the trigger points under the regular points, meaning I pull the reg. points & plate and the trigger is underneath and inside the distributor?

I wasn't certain if I even had trigger points (this is only my 3rd 914 but the last one I had was over 30 years ago. Thanks again all.

Posted by: brp986s Oct 24 2010, 09:08 PM

2 phillips screws mount the triggers into the side of the distributor - no need to remove ign points/plate.

Posted by: luskesq Oct 24 2010, 09:25 PM

QUOTE(brp986s @ Oct 24 2010, 06:39 PM)

All stock 1.7 have the trigger points in the distributor. The way to test them is have someone turn over the engine while you measure continuity between the center and either of the the outer pins of the distributor. The circuit should open and close once per rev of the distributor rotor. One side of the trigger will fire injectors 1 & 4, the other 2 & 3. As the triggers wear, the slider blocks wear out - the circuit fails to open, and the ecu doesn't receive the signal to fire the injectors.The function of the trigger points is unrelated to the tps. good luck.

Buried under the vacum hose to the advance is a 3 wire plug into a receptcle on the side of the dist. That piece goes into the dist but I don't see screws holding it in place. It is lower than the point plate so I don't see how I can either service it or replace it without pulling the plate (with points) off? Am I missing something (likely)? Thank you again for the help.

Posted by: ejm Oct 25 2010, 04:32 AM

You need to pull the distributor to remove the trigger points.

QUOTE(luskesq @ Oct 24 2010, 08:40 PM)

No injector clicking with key on and opening the throttle switch on 1 or 2. 3 & 4 click.

Again...doesn't sound like your problem is the trigger points.

Posted by: luskesq Oct 25 2010, 10:17 AM

Thank you for confirming what I suspected. I intend to confirm good ground connections as you suggested first before pulling the dist. Do easy part first & cross fingers.

Posted by: Tom Oct 26 2010, 10:04 AM

An easy test is to hook up a meter to the injector plug to see if the ICU is sending a signal to the injectors. Plug has two contacts, one is ground. So check that the ground is good, then put the meter to the other connection and turn over the engine and see if the voltage gets to the injector. That way you are checking that the ground is good also from the injector to the rear junction for the inj. ground wires.
Tom

Posted by: rick 918-S Oct 26 2010, 10:58 AM

I made a simple test light from a couple small wire connectors and a side marker socket from a 1980's GM car. The bulb was a 194 which is a small single filament bulb. I unplugged the injector and plugged the test light into the socket. Crank the car and watch the bulb. If the light flashes the wiring is good and the injector is dead. If no joy unplug the ground side of the test light from the injector socket and ground it. Re-test. If the light flashes the ground is dead. These old harnesses get brittle and can snap off. mid-stream causing a failure.

Posted by: realred914 Oct 26 2010, 11:00 AM

QUOTE(Tom @ Oct 26 2010, 09:04 AM)