Help! Engine started missing bad & needs to be fixed quick

[Tidybuoy]

Help! This is for a 1974 L-Jet 1.8

I was driving to work today just like normal - engine was running perfect. As I pulled into the parking lot, the car started missing (bad). Felt like it was running on two cyl.

I drove at lunch & the car idles fine but starts to mis & cough as I step on the throttle.

My Theories:

Throttle position sensor - car has been jerking on occasion lately.
Petronix - just installed 2 months ago
Head Temp Sensor (it's new too).

I need to fix this quick. I'm going to the mountains tomorrow afternoon (bringing a new date!). If necessary, I will drive another car but I really, really, wanted to take the 914.

I have a spare throttle position sensor & I'm going to switch out tonight - just in case.

I may switch back to points too - just in case

Any Thoughts would be Great.............................Vern

[Jared at Pelican Parts]

I'd check for loose wires, cables, vacuum hoses... Sounds like something may have gotten knocked loose..

[Ferrell]

Contact trigger points perhaps.

[Dave at Pelican Parts]

The throttle position switch in the 1.8 doesn't do an awful lot--and will almost certainly not make the car buck. There are no FI trigger points. The 1.8's L-jet FI gets its RPM signal from the main ignition points.

I'd look for loose wires and hoses, or ones with poor connections, just as Jared said.

--DD

[sean_V8_914]

double relay plug under the battery tray. clean it and slightly re-crimp the contacts. this thing will make your L-Jet buck intermittently. car will not run if temp II circuit opens. The 4 pack of resistors AKA cigarett pack, for the injectors is in the same location as the double relay. battery acid and acid vapor does a number on these components. My 1.8 had an open in teh cigarett pack that caused #2 injector not to fire intermittently. I hope this solves your problem.