1911 injectors?, re-hash, I know Options

[r3dplanet]

Hi.

Does someone know which injectors are best to use with a 1911cc engine? The D-Jet system is from a 1973 1.7 liter engine. I originally did not know that the engine had larger displacement and tried to use the VW black injectors, but those didn't squirt enough fuel. The yellow injectors were near impossible to find but I think those are also not adequate.

Your thoughts? Share them with me.

Thanks!

[McMark]

I don't think the injectors are the problem. I've always understood the stock injectors to be a bit on the large size for our engines.

You can also just bump the fuel pressure to give enrichment across the board. So 1.7 injectors could be fine by running an extra few PSI. Worth a shot for free.

[r3dplanet]

Interesting...

The injectors I was using aren't stock. The stock yellow injectors were unavailable at the time, so I switched to the black injectors for 1600cc engines. At the time I didn't know the displacement was 1911cc. The stock displacement is 1679cc so I figured the black injectors would be good enough. I could never get the engine to run right because it ran horribly lean as you can imagine. My thinking is that the black injectors are inadequate for the job.

I'll try bumping the fuel pressure just as soon as I put the engine back together. Just planning ahead.

I appreciate your thoughts.

-m.

I don't think the injectors are the problem. I've always understood the stock injectors to be a bit on the large size for our engines.

You can also just bump the fuel pressure to give enrichment across the board. So 1.7 injectors could be fine by running an extra few PSI. Worth a shot for free.

[McMark]

Another thought....

You might also tee in a vacuum gauge with your MPS hose, just to see what sort of vacuum signal you're getting at idle. Maybe they swapped in a cam with more overlap and the MPS isn't getting enough vacuum. Inserting a small orifice (MIG welder tips work well for this) can slow down the vacuum signal, sort of averaging. That may make a difference as well.

[r3dplanet]

I think you're a mind reader sometimes.

Yes, the autopsy showed that it had a hotter cam in it now that I remember some of the details. I'm toying with the idea of maybe just selling the D-Jet as a complete running kit. I went through the MPS with a rebuild kit and verified its function with a Fluke meter.

I'm probably getting ahead of myself. Maybe I should figure out whether I'll keep or sell the D-Jet assembly before I dink with it too much. I just didn't want to sell it unless I knew for sure it was perfect.

Hmm... wish I had a 1.7 runner sitting here.

Thanks!

Another thought....

You might also tee in a vacuum gauge with your MPS hose, just to see what sort of vacuum signal you're getting at idle. Maybe they swapped in a cam with more overlap and the MPS isn't getting enough vacuum. Inserting a small orifice (MIG welder tips work well for this) can slow down the vacuum signal, sort of averaging. That may make a difference as well.