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]

You haven't run out of ideas - you haven't adjusted the valves yet (IMG:style_emoticons/default/smile.gif)

1. Adjust valves
2. Set dwell (45 to 50 degrees) and THEN set timing right where it should be 27 BTDC

Must do dwell before timing, as dwell adjustments will throw dwell off. With those variables out of the way, you can see if there's any improvement or if you need to get into testing / adjusting specific D-Jet components and vacuum setup.

[isdyl]

Ok thanks - I was hoping to avoid climbing under the car but I can see I'm going to have to. At the moment it won't idle or hold steady revs to set the timing. Would the valve clearances make that much difference please?
Dylan

You haven't run out of ideas - you haven't adjusted the valves yet (IMG:style_emoticons/default/smile.gif)

1. Adjust valves
2. Set dwell (45 to 50 degrees) and THEN set timing right where it should be 27 BTDC

Must do dwell before timing, as dwell adjustments will throw dwell off. With those variables out of the way, you can see if there's any improvement or if you need to get into testing / adjusting specific D-Jet components and vacuum setup.

[BeatNavy]

I will add that if you've had the distributor in 100 different settings you are probably struggling to even know which direction to go at this point. I've been there, and it's usually caused by timing mark confusion or even a distributor gear being aligned differently than stock. I'd put the engine at TDC. Verify where the timing mark is on the fan (and verify that you know which mark is 27 BTDC). See if the rotor is generally pointing toward plug 1. Understand which way the fan rotates with engine running and which way you need to turn the distributor to advance (CCW to advance, CW to retard).

You need to get it within the right "ballpark" so you can make fine adjustments.

[BeatNavy]

Ok thanks - I was hoping to avoid climbing under the car but I can see I'm going to have to. At the moment it won't idle or hold steady revs to set the timing. Would the valve clearances make that much difference please?

If the valves are significantly out of adjustment yes. You're going to need to verify / adjust them at some point anyway (unless you know they were set correctly before).

Goal at this point is to get everything close enough that it will run / idle enough for you to make fine adjustments. It may help to have another person available. It takes practice to do the timing by yourself, but it's certainly possible. One hand on throttle body one hand on light, leaning over timing hole, one eye on mark, one eye on tach...etc.

[isdyl]

Yes I'm not sure where it is set now! I initially set it statically to TDC (the white mark I think) and it started in a similar fashion to the video. I then moved it in about 1 degree increments about 30 times in both directions, each time starting it to see if it would improve the running. This is why I assumed it wasn't a timing issue as I'd tried it in every position possible! I'll check the valve clearances. It's something I'll need to do as some point anyway.
Dylan

I will add that if you've had the distributor in 100 different settings you are probably struggling to even know which direction to go at this point. I've been there, and it's usually caused by timing mark confusion or even a distributor gear being aligned differently than stock. I'd put the engine at TDC. Verify where the timing mark is on the fan (and verify that you know which mark is 27 BTDC). See if the rotor is generally pointing toward plug 1. Understand which way the fan rotates with engine running and which way you need to turn the distributor to advance (CCW to advance, CW to retard).

You need to get it within the right "ballpark" so you can make fine adjustments.

[BeatNavy]

Don't forget that dwell though (assuming you have a conventional dizzy with points)! If that's not in spec that'll cause a host of issues too.

Good luck, Dylan!

(IMG:style_emoticons/default/beer.gif)

Yes I'm not sure where it is set now! I initially set it statically to TDC (the white mark I think) and it started in a similar fashion to the video. I then moved it in about 1 degree increments about 30 times in both directions, each time starting it to see if it would improve the running. This is why I assumed it wasn't a timing issue as I'd tried it in every position possible! I'll check the valve clearances. It's something I'll need to do as some point anyway.
Dylan

I will add that if you've had the distributor in 100 different settings you are probably struggling to even know which direction to go at this point. I've been there, and it's usually caused by timing mark confusion or even a distributor gear being aligned differently than stock. I'd put the engine at TDC. Verify where the timing mark is on the fan (and verify that you know which mark is 27 BTDC). See if the rotor is generally pointing toward plug 1. Understand which way the fan rotates with engine running and which way you need to turn the distributor to advance (CCW to advance, CW to retard).

You need to get it within the right "ballpark" so you can make fine adjustments.

[TheCabinetmaker]

Have you checked vacuum on the mps? How about the throttle position switch? Condenser on the distributor? Have you actually checked or set dwell? Have you ohmed the head temp sensor?

[Bleyseng]

Have you checked vacuum on the mps? How about the throttle position switch? Condenser on the distributor? Have you actually checked or set dwell? Have you ohmed the head temp sensor?

What he said....

Also is the advance working on the distributor? 45 grease on the weights inside can freeze em and so no advance.

[Spoke]

It would help to have an AFR sensor to tune your FI. Good running FI is all about proper fuel mixture and without AFR info it is very difficult to tune FI. You may want to consider installing an oxygen sensor and gauge or logger to get it tuned well.

[isdyl]

Hi - Thanks for your replies. I have checked the head temp sensor and the air sensor. The MPS holds vacuum, I haven't actually checked the vacuum advance on the distributer so will look at that. I don't have a dwell meter so have the points set to 0.4mm gap. How do I check the condenser please? I haven't done anything with the throttle position switch either - is that something that should be adjusted somehow please?
Many thanks, Dylan

[euro911]

(IMG:style_emoticons/default/agree.gif) on the valve adjustment taking priority. My '71 (with a 1.7L at the time) would hunt for an idle when I bought it. I checked all the FI components, replaced all the vacuum and fuel lines, checked/adjusted the dwell & timing, all to no avail. After performing a valve adjustment, the idle hunting went away. One cylinder had the valves adjusted too tight.


The TPS board's traces can get worn down and cause dropouts. You may get by trying to clean the traces and repositioning the 'fingers' to a better looking portion on the trace(s).

If the traces are real bad, 914 Rubber sells new reproduction TPS boards.

[isdyl]

Thanks - I'd better get under that car....

(IMG:style_emoticons/default/agree.gif) on the valve adjustment taking priority. My '71 (with a 1.7L at the time) would hunt for an idle when I bought it. I checked all the FI components, replaced all the vacuum and fuel lines, checked/adjusted the dwell & timing, all to no avail. After performing a valve adjustment, the idle hunting went away. One cylinder had the valves adjusted too tight.


The TPS board's traces can get worn down and cause dropouts. You may get by trying to clean the traces and repositioning the 'fingers' to a better looking portion on the trace(s).

If the traces are real bad, 914 Rubber sells new reproduction TPS boards.

[isdyl]

Follow up - TPS is all working correctly.

Hi - Thanks for your replies. I have checked the head temp sensor and the air sensor. The MPS holds vacuum, I haven't actually checked the vacuum advance on the distributer so will look at that. I don't have a dwell meter so have the points set to 0.4mm gap. How do I check the condenser please? I haven't done anything with the throttle position switch either - is that something that should be adjusted somehow please?
Many thanks, Dylan

[BeatNavy]

These are legit suggestions, but IMO you do have to prioritize the fundamentals such as valves and dwell/timing (which can be difficult if it won't stay running of course). If it won't stay running after that then it is definitely time to test / troubleshoot the D-Jet components that have the biggest impact on mixture (e.g., MPS and CHT). After you get it to the point that it will stay running, then you can focus things that impact drivability and reliability more (e.g., TPS, AAR, CSV, decal valve, etc.). As Spoke says the AFR is good for troubleshooting that at some point if you don't already have one.

[isdyl]

Great - thanks. I'll get on to it. D

These are legit suggestions, but IMO you do have to prioritize the fundamentals such as valves and dwell/timing (which can be difficult if it won't stay running of course). If it won't stay running after that then it is definitely time to test / troubleshoot the D-Jet components that have the biggest impact on mixture (e.g., MPS and CHT). After you get it to the point that it will stay running, then you can focus things that impact drivability and reliability more (e.g., TPS, AAR, CSV, decal valve, etc.). As Spoke says the AFR is good for troubleshooting that at some point if you don't already have one.

[Tdskip]

Just a thought - you have flow when testing the injectors off the car by are you sure you are getting flow when on the car?

Question for the brain trust here - does his set up have a cold start injector or any other way to getting fuel to the car outside the four main injectors?

[isdyl]

Hi - there is a cold start injector but it’s not yet plumbed into the fuel hose that runs past it between cylinders 2 and 4. I did wonder a bit about fuel pressure and flow as I only get 2 bar when the pump is running. As soon as it stops running (like when the engine is off) the gauge drops to about 1.2 bar. I assumed it’s leaking back past the pump. D

Just a thought - you have flow when testing the injectors off the car by are you sure you are getting flow when on the car?

Question for the brain trust here - does his set up have a cold start injector or any other way to getting fuel to the car outside the four main injectors?

[ndfrigi]

Hi - there is a cold start injector but it’s not yet plumbed into the fuel hose that runs past it between cylinders 2 and 4. I did wonder a bit about fuel pressure and flow as I only get 2 bar when the pump is running. As soon as it stops running (like when the engine is off) the gauge drops to about 1.2 bar. I assumed it’s leaking back past the pump. D

Just a thought - you have flow when testing the injectors off the car by are you sure you are getting flow when on the car?

Question for the brain trust here - does his set up have a cold start injector or any other way to getting fuel to the car outside the four main injectors?

fuel pressure should be between 28 and 31 psi. probably your fuel pump need replacement or getting low voltage.

[isdyl]

Yes that’s about 2 bar - should it hold at that when the engine is off please? D

Hi - there is a cold start injector but it’s not yet plumbed into the fuel hose that runs past it between cylinders 2 and 4. I did wonder a bit about fuel pressure and flow as I only get 2 bar when the pump is running. As soon as it stops running (like when the engine is off) the gauge drops to about 1.2 bar. I assumed it’s leaking back past the pump. D

Just a thought - you have flow when testing the injectors off the car by are you sure you are getting flow when on the car?

Question for the brain trust here - does his set up have a cold start injector or any other way to getting fuel to the car outside the four main injectors?

fuel pressure should be between 28 and 31 psi. probably your fuel pump need replacement or getting low voltage.