Finally got around to working on the 914 lately, got the 1.7 Djet motor fired up surprisingly easily with only static timing it. Put in new plugs, wires, cap, rotor, Pertronix, CHT, gaskets, fuel hoses, fuel filter, etc.

Anyways, to my problem.

I jacked up the rear to tighten some things up and now that it's back on the ground again it won't restart. I figured the pump just needed to be cycled quite a few times to get the fuel pressure back up, but after 4 or 5 times of cycling the pump, I heard a very loud POP, almost like something blew up or a backfire. What could this be ? I was only cycling the fuel pump circuit on and off.
I looked around everywhere and can find nothing, no leaking fuel, nothing burned or exploded into pieces. Still won't start, just hiss and pop occasionally now. Pump still turns on fine.

I am getting spark, and the injectors are firing.

Any ideas?

You just timed it? Got a pic of the position of the dizzy, what's the actual psi on fuel rail?

Just rough timed it to get it running by turning the engine to TDC and lining up the dizzy. The dizzy drive gear looked correctly oriented as in Haynes manual.

Have yet to check fuel pressure, my new cheap Harbor Freight gauge leaked like crazy. I'll get a good one tomorrow.

You're welcome to borrow my f.p. gauge.

Pertronix just installed? You may want to revisit that. The pop and no start throw up a red flag on ignition.

Mike

Thanks. I might need to borrow your gauge, I'll let you know Mike.
I figured it might've been the pertronix unit, but I'm still getting spark...

I wonder if your distributor wasn't seated all the way and jumped up off the gear. It might still turn and give a spark just dragging on top of the gear. You might have heard a cylinder fire with a valve open, if the distributor is out of place, giving you the pop sound. Might as well check the vaccum hoses to see if any of those blew off.

Thanks Mels, didn't think of that, I'll double check the dizzy.


Now I'm just getting a loud pop/backfire out the intake when keying the fuel pump on

Intake valves to tight

timing way off ... best guess is to advanced ... fire before valve is closed.

I'll 2nd wrong ignition timing.

I'll double check the valves again as sugggested.

What should be my procedure for rough timing just to get it running? I turned the engine to TDC (felt for compression on #1 cyl and watched for white mark on fan) and then installed dizzy.

Any luck yet? It sounds like your getting the engine set up correctly, #1 compression stroke, lining up the paint mark. Your rotor should be pointing to the little mark on the edge of the distributor body, that's #1 position. Make sure your cap is wired to match that. Now to get close with the timing, put the distributor in running shape with the cap on, pull #1 plug or use a spare plug, connect the #1 wire to the loose sparkplug, ground the sparkplug metal body with a jumper wire. Now turn on the key to the run position, do not crank the engine over. With the distributor loose enough to turn, rotate the distributor body till you hear or see the #1spark plug spark. If everything is set correctly, the distributor should be pretty close to a decent initial timing. Hope this helps, Mike

Went through today and readjusted valves, found a few of them tight (as Ron stated above) so hopefully I've got them set better this time.

And yes you were all correct on the timing, I think I had it 180deg off.

After Rechecking the TDC mark on fan and feeling for a compression stroke from #1 cyl, I realized the dizzy rotor was pointed at #3. Reinstalled dizzy around, then used 914Mels' advice above to set initial timing: ignition on, rotate loosened distributor until #1 plug sparked. This got it fired right up. So how did it run before if 180* off?

Idles a lot smoother now after the valve adjust, though revving up gives noticeable knock/unsmooth running. I know I haven't even timed it yet and I assume that's why, I'll get that done tomorrow.

Thanks all for your help. Much appreciated.

PS: I still don't know WTF that huge backfire/pop/explosion sound was a few days ago.

I experienced almost the exact same senario back in may. Mine back fired too, and somehow when taking the dizzy out and putting it back in, pulling the cap etc. i changed the wires out and had 4 and 3 switched. But then getting that straight, the timing was far enough off that it backfired, and i had the TDC right, valves, etc but i had the dizzy rotated off at first. if this is d-jet , once you set your timing- 27' before tdc at 3500rpm- you should be good to go, as long as your dwell and points gaps are set-, and no vac leaks( i'm still fighting that battle)

good luck. let us know how it runs and idles once you get all that set.

PW.

Edit: i see you have petronix so ignore that about the points, but they can be bad or have too little of an air gap, - i have not had petronix but do have hot-spark which is almost the same thing. and when running was running great except for a hessitation or occasional hickup and that is due to a worn TPS- which is getting replaced soon.

Thanks for the replies all. ...
Had the car running pretty decently. I was getting pretty close on timing but had troubles finely dialing in the timing . Idled well 1000rpm after warming up, this is with no vac hoses on the dizzy, only MPS hoses and plenum to PVC valve. I have deleted my decel valve and no air filter hooked up yet. Hooked up dizzy vaccum lines and idle raised up a few hundred rpm




Here's my newbie timing questions.......
Using an advance timing light set at 27* and engine at 3500+ -- when the fan impeller's white TDC mark is headed too far off towards the pass. side of car, is this too far advanced or retarded?

Same question for rotating the dizzy, is clockwise advancing or retard?

Also, how much should I rely on my timing light's advance dial? Or should I just use the red 27* (hard to spot on my fan) marker?

Finally, timing should be advancing to 27* at 3500 rpm, What should I be at idle?




Now it won't start again. Was getting some backfiring but no start, so i Set initial timing again as 914Mels suggested below, and still not getting it to fire up. I'm smelling slight gas so I can assume injectors are firing, and getting spark

Appreciate the help all - z

If you are using a light with the knob and have the knob set at 27 degrees, you use TDC (white mark) as your timing reference. If you use the red mark (27 degrees) you have just set the total advance to 54 degrees BTDC ..... WAY OVER ADVANCED. You are igniting the mixture while the intake valve is still open (more than likely) and the "pop" will be a backfire out of the intake. To retarded, the gas mixture is still burning when the exhaust valve opens and the "pop" will be experienced in the exhaust tract.

Turning the dizzy clockwise RETARDS timing ... counterclockwise ADVANCES timing.

Never cared what the idle timing is 'cause the timing is set at and elevated RPM .... hell, on a six, you check the timing at 6K, but idle timing is 5 degrees After Top Dead Center.

Retarded timing will cause the car to start easily but it will have no power as the gas/air mixture is being ignited to late to get the full force of the bang (expansion of gasses). Over advanced is like putting pressure in the cylinder as the piston is trying to move up in the cylinder trying to stop it.

I tossed my timing light with the advance knob. Anyway, once you get it timed right, let the car idle, start with 0 on the knob and slowly turn it until the white mark appears in the timing notch ... record the reading on the knob and you will have the idle advance number.

Rock and Roll

*** Sorry Phil ... was editing while you were posting.

You use the white mark,put the dial at 27. Should be. Set now at 3500 rpm with the vac dis objected from the distributor, but have your air cleaner on the t.b., plug all hoses( according to haynes)
I had the same backfire, not running because I had it way too advanced. Now when you hook up the vac to the distributor, it goes to the t.b. from retard side of vac can. Some only have a retard 75-76, but the 73, 74 I believe have both. When I first got my car the p.o.had the advance side connected to the plenum, it should not be there. So recheck your hose attachments and their locations.

Phil

I would add one thing if you are going to use the stock distributor and Vac advance retard.

You check the hoses for the right locations, and evac. the "dashpot" or diaphram for leaks.

Ask me how I know.

Good luck and have fun.