Could a vacuum leak or poor ground be a starting killer?, 73 914 2.0 - EARLY Sept 72 VIN4732901102 Options

[avidfanjpl]

I am having a world of hurt. Car ran on Saturday. Drove it an hour. Got slightly warm and it ran rich the whole time. Crack in the dual tube elbow into the Manifold corrected last night.

Gapped at .017 to start. Waiting for dwell/vacuum/fp gauge/timing light in mail.

Backfires and will not start. I have the ecu at 11, all electrical checks out, changed ht sensor and manifold sensor last night.

Have one chinese relay but the rest are wehrle and good

chinese one ran the fan so it seems OK All hoses new. Fuel hoses too. How serious is a poorly adjusted fps on the drivers side? I am sure mine is not on 29psig.

I am wearing out my solenoid and maybe my ignition switch!

Thanks!

John

Any ideas? (IMG:style_emoticons/default/WTF.gif) (IMG:style_emoticons/default/wacko.gif) (IMG:style_emoticons/default/hissyfit.gif)

[Root_Werks]

Check your points again. Make 100% sure the little ground strap in the dizzy isn't broken or the green wire didn't rub up against something grounding out. Sounds like that might have happened.

[realred914]

whats the fps you refer to? duel tube elbow?

rich running on a D-jet (stock 2 liter system) can be worn trigger points that are bouncing, high resistance head temp sendor or wire / resistor that conects to it, defective manifold pressure sendor or some bad wires to the sendors and brain.
the ecu know that I think you refer to with the 11 shoudl be basically be set at the mid range, it has only a small effect on mixture however.

aslo supper rich could be fromt eh cold start injector being on, dissconnect it to be sure that is not it either. your ignition switch shoudl have no effect on the mixture as it energizes a relay to run teh injection electrical so long as th ekey switch trips the relay it is not a problem

sine you say it was running prior to doing some work suggest you look carefully at wires and vacuum hoses in areas you did work for broken connections and leaks

good luck (IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/driving-girl.gif)

[avidfanjpl]

Thanks Root Werks and RealRed!

I meant the Manifold Pressure Sensor, and later I was talking about stupidly messing with the Fuel Pressure Regulator. Dope that I was, I have to wait for my fuel pressure meter to arrive and undo my work from Saturday.

Replacing the dual elbows into the MPS may have worked, but the backfire last night was so loud I have to wait till this afternoon to try again.

Root Werks - The green wire seems intact. Rechecking the gap to .17 later today.

Checked all hoses, cut some for tighter fits, but I think I may have a bad trigger.

It sends out some spurious signals when testing with a continuity tester when cranking, but the damn thing ran rich but pretty well on Saturday before I messed with it.

Truly, as it warmed up in SoCal, it starting messing up.

THANKS!

John

[Rand]

Root Werks - The green wire seems intact. Rechecking the gap to .17 later today.

Be sure and check the other wire Dan mentioned. It's a little braided wire that connects between the advance plates inside the distributor. Sometimes one of the ends will come loose where it's soldered to the plate, and it will cause your exact symptoms. (Spark will be super weak, it won't start, and when it tries you'll get a nasty loud backfire. Happened to me.)