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

[ctc911ctc]

Hi,

I went down all of the paths that you did with a barn find that had not been running for 30 years.

Djet will only work correctly if the vacuum system is solid.
Repeat after me:
Djet will only work correctly if the vacuum system is solid.

Hate to suggest this but the Plenum is very susceptible to leaks, especially if the car has been in humid geography.

Take the Plenum out and get some plumbing stoppers. Plug it up and pressurize then immerse in water. Mine had a dozen leaks. I welded AND JB Welded (epoxy) the thing. Re-installed in a car that I had already:

Valves Adjusted
Timing
Rebuilt Throttle Body (throttle position switch)
New Fuel Pump
All new hoses
Calibrated Fuel Pressure to 29 psi
rebuilt injectors.
New MPS
New Engine Temps Sensor


When the plenum was complete, the car started, idled, went from 1200 cold to 900 after warmed up.

The next thing I chased was Exhaust leaks. But that is another thread.

[isdyl]

Thanks - ok so I've done a bit of testing this morning and found quite a bad leak around the cold start valve. I put duck tape over the throttle body opening, blocked the AAV, and blew into the MPS hose whilst spraying with leak detection spray. I don't need a cold start valve here as it's quite warm so I removed it and covered the hole with aluminium tape.
It now starts up ok and revs at about 1500rpm. It holds for a couple of seconds but then dies. I'm now wondering if it's getting enough fuel, but when running the fuel pressure stays constant at 29 psi.
Dylan

Hi,

I went down all of the paths that you did with a barn find that had not been running for 30 years.

Djet will only work correctly if the vacuum system is solid.
Repeat after me:
Djet will only work correctly if the vacuum system is solid.

Hate to suggest this but the Plenum is very susceptible to leaks, especially if the car has been in humid geography.

Take the Plenum out and get some plumbing stoppers. Plug it up and pressurize then immerse in water. Mine had a dozen leaks. I welded AND JB Welded (epoxy) the thing. Re-installed in a car that I had already:

Valves Adjusted
Timing
Rebuilt Throttle Body (throttle position switch)
New Fuel Pump
All new hoses
Calibrated Fuel Pressure to 29 psi
rebuilt injectors.
New MPS
New Engine Temps Sensor


When the plenum was complete, the car started, idled, went from 1200 cold to 900 after warmed up.

The next thing I chased was Exhaust leaks. But that is another thread.