1.7 d-jet '73 almost running Options

[isdyl]

Hi all - so I've refitted d-jet on my 1.7 which had a single weber when I bought it. It's almost running but I've run out of ideas as to what to adjust or check. I've recorded a video of it starting. You'll hear that it starts quite lumpily and wants to stall. I manage to get the revs up by feathering the throttle and they go up to 2.5 or 3000 revs on their own for a second, and then it all dies again. I can keep it running by feathering the throttle again.

https://www.youtube.com/watch?v=Y06kdQC2IZg

Fuel pressure when running is 2 BAR. Theres no cold start valve connected. All injectors are 'squirting' as I took them out and checked in a jam jar. I've tried adjusting timing, mixture screw, air screw. I haven't checked the valve clearances yet but have had the distributor in 100 different settings with no improvement. I just wondered if anyone has any ideas please?
Thanks, Dylan

[BeatNavy]

I've heard conflicting things on whether it should hold pressure after shutting off (and how long), and whether there's a check valve in the old 3 port pump to keep up pressure (or not). I really cared when my old engine ALWAYS required two starts (unless I immediately feathered throttle). I figured it was not getting enough fuel initially, and I did notice that my fuel pressure dropped off pretty steadily after shutting off the engine. Having said that, I don't think that was the root cause of the minor issue.

In terms of whether it's an issue for you: if you have a leaking injector that is letting fuel bleed out (both with engine running and not running) that would be an issue - cause an over rich fuel mixture. If you're maintaining pressure while the engine is running and not otherwise leaking fuel anywhere, I wouldn't think it would be a significant problem.

If you suspect fuel delivery might be an issue even after confirming that the injectors are firing, you need to look for some clues. Be careful about chasing your tail though - focus on getting things right in one area (e.g., ignition and timing, then fuel delivery, etc.) and then move on to the next.

If you have a conventional dizzy with points, get a dwell meter.

More reading: https://members.rennlist.com/pbanders/DJetParts.htm

[isdyl]

Thanks very much, and yes I'm on the case re the valve clearances - new feeler gauges just arrived! D

I've heard conflicting things on whether it should hold pressure after shutting off (and how long), and whether there's a check valve in the old 3 port pump to keep up pressure (or not). I really cared when my old engine ALWAYS required two starts (unless I immediately feathered throttle). I figured it was not getting enough fuel initially, and I did notice that my fuel pressure dropped off pretty steadily after shutting off the engine. Having said that, I don't think that was the root cause of the minor issue.

In terms of whether it's an issue for you: if you have a leaking injector that is letting fuel bleed out (both with engine running and not running) that would be an issue - cause an over rich fuel mixture. If you're maintaining pressure while the engine is running and not otherwise leaking fuel anywhere, I wouldn't think it would be a significant problem.

If you suspect fuel delivery might be an issue even after confirming that the injectors are firing, you need to look for some clues. Be careful about chasing your tail though - focus on getting things right in one area (e.g., ignition and timing, then fuel delivery, etc.) and then move on to the next.

If you have a conventional dizzy with points, get a dwell meter.

More reading: https://members.rennlist.com/pbanders/DJetParts.htm