D-Jet Conversion not going as planned., Car starts but will not run. Options

[slapshot]

The CHT resistance is 2150 @ 65 degrees.

[emerygt350]

That seems reasonable.

[emerygt350]

One thing you could try is lowering the fuel pressure. If it's too rich that is an easy way to do it without messing with anything. If you drop it down to 25 and it runs better, you know it's overly rich. Then you can try and figure out why.

[slapshot]

I will try that.

[slapshot]

No change after turning it down to 24. The engine starts while cranking but dies a second later. I tried starting fluid again, but it just flooded, and it wouldn’t crank over for a while. If I give it full throttle after cranking, it runs for a couple of seconds longer, but that’s it.

Next steps: I plan to pull the ECU and take measurements at the pins. I also want to pull the injectors from the intake and place them in jars to observe the fuel flow and compare the amount from each one. I previously tested them on the bench and verified they had good flow with pressurized carb cleaner.

The MPS has a small leak, but it's not extreme. I think it should still be good enough for the car to run. Maybe not great but should run. Thoughts?

[brant]

fuel spark timing

I would verify spark with a timing light at the plug wire
And that the injectors were opening with a noid light

Before tearing it apart

[slapshot]

I'm not able to check timing since it will not run but it was running great with carbs before I put D-Jet in although I did pull the dist to remove the air tin to install the CHT. I didn't move the adjustment bracket, only pulled it straight out and put it back in. My paint marks on the dist line up so I'm 99% sure its spot on.

I will pick up a noid light and test that. Thanks for the idea.

[emerygt350]

"and it wouldn’t crank over for a while" what exactly do you mean here? Is the engine no longer turning over or it's turning over but not firing?

[slapshot]

After spraying a good amount of starter fluid into the throttle body it would not crank over for about 15 or so seconds. After that it would crank over then die as before.

[JeffBowlsby]

Do you know if this ECU is functioning? You can have it tested and repaired if necessary. But I would only do this if everything else checks out.

https://www.ecudoctors.com/

[slapshot]

I don't know. I'll get a noid light tomorrow to test if each injector is getting a signal from the ECU.

[emerygt350]

Again, i am confused by " it would not crank over for about 15 or so seconds. After that it would crank over then die as before." Is the engine failing to turn over at all or it just isn't 'firing'?

I assume the engine is turning over, just not firing.

As you poke around you should just really quick verify the spark plug wires are all going where they are intended.

when it dies, does it just stop running immediately or does it kind of peter out?

[dr914@autoatlanta.com]

no calibration necessary, make sure that you have good dwell and timing and fuel pressure as you crank the car, and that the trigger points are plugged in to start, we can work through this but many variables to deal with since it is a fresh installation. (you can also spray some brake clean into the throttle body to make sure that it keeps running to totally eliminate the ignition system

I am converting back to D-Jet and my car will start but dies right after. It will not rev up applying throttle. I have a 1975 914 2.0. It was running great with Weber 40s prior.

The D-Jet system is from a 1974 2.0. All the parts came in visibly good condition. TPS calibrates good, AAV tested good, Thermo sensor good, air intake temp sensor good, and a new cylinder head temp sensor. The only test that I think is failing is the vacuum test on the MPS. It leaks. Video of testing the MPS.. The MPS has also been rebuilt at some point. The original part # has been removed. There's a good chance it is not calibrated for my car. I have all new vacuum hose and fuel pressure is between 28 and 30.

I don't have any tools to calibrate the MPS. Should I try turning the inner screw on the MPS to see if it helps? Or should I send it to someone to have it rebuild again and recalibrated? If the later do you have any recommendations on who to send it to?

[rjames]

As MJames stated, the MPS is critical.

Yes yours doesn't hold pressure, but it doesn't drop so fast that the car shouldn't at least start and run for a bit, albeit likely with a surging idle.

Did they rebuild the MPS such that you can make adjustments without opening it up?
If it were my car I'd try turning just the inner screw a quarter of a turn clockwise first, and if that didn't work, turn it the same amount the other way. Just keep track of how much you're moving it so you can get it back where it was if need be. Given your description, if the cause is the MPS being out of adjustment, a quarter to half turn one way or the other would either allow the car to idle, or rule out the MPS as the issue.

[slapshot]

Again, i am confused by " it would not crank over for about 15 or so seconds. After that it would crank over then die as before." Is the engine failing to turn over at all or it just isn't 'firing'?

I assume the engine is turning over, just not firing.

As you poke around you should just really quick verify the spark plug wires are all going where they are intended.

when it dies, does it just stop running immediately or does it kind of peter out?

Ignore the "it would not crank over for about 15 or so seconds.", that was only after I sprays quite a bit of starter fluid in the TB.

The car does start, barely, sputters and dies after a second or two.

I verified the plug locations. The 123 Distributor plug position is different than my previous one so the plug wires in the video might look off but its right for this Dist.

[Spoke]

The engine starts while cranking but dies a second later.

If the dizzy isn't hitting the injector contacts or whatever is in the 123 dizzy, the engine will not continue to run after the initial 2 sec charge-up when the key is turned on.

Have you confirmed the dizzy is hitting the contacts for the injectors? When I was testing the DJET for my 914 before mounting on the engine, I would turn the dizzy by hand and could hear the injectors firing confirming the dizzy is hitting the injector contacts.

[slapshot]

As MJames stated, the MPS is critical.

Yes yours doesn't hold pressure, but it doesn't drop so fast that the car shouldn't at least start and run for a bit, albeit likely with a surging idle.

Did they rebuild the MPS such that you can make adjustments without opening it up?
If it were my car I'd try turning just the inner screw a quarter of a turn clockwise first, and if that didn't work, turn it the same amount the other way. Just keep track of how much you're moving it so you can get it back where it was if need be. Given your description, if the cause is the MPS being out of adjustment, a quarter to half turn one way or the other would either allow the car to idle, or rule out the MPS as the issue.

They did. I have access to the inner screw. The outer is marked with paint. I have debated adjusting the inner but will not be doing that until I have verified all injectors are firing and all measurements on the ECU pins are good.

How sensitive is that inner screw? If I move it could it cause damage to the engine?

[slapshot]

The engine starts while cranking but dies a second later.

If the dizzy isn't hitting the injector contacts or whatever is in the 123 dizzy, the engine will not continue to run after the initial 2 sec charge-up when the key is turned on.

Have you confirmed the dizzy is hitting the contacts for the injectors? When I was testing the DJET for my 914 before mounting on the engine, I would turn the dizzy by hand and could hear the injectors firing confirming the dizzy is hitting the injector contacts.

I have not. I do have the yellow and white wires from the 123 plugged into the ECU harness but I haven't confirmed that its is working. My noid light will be here this evening and I can verify the injectors are getting a signal from the ECU. If they are that would indicate the dizzy is triggering right? I don't want to move my dizzy ATM since I set it before with the webers and it was good then.

[Spoke]

The engine starts while cranking but dies a second later.

If the dizzy isn't hitting the injector contacts or whatever is in the 123 dizzy, the engine will not continue to run after the initial 2 sec charge-up when the key is turned on.

Have you confirmed the dizzy is hitting the contacts for the injectors? When I was testing the DJET for my 914 before mounting on the engine, I would turn the dizzy by hand and could hear the injectors firing confirming the dizzy is hitting the injector contacts.

I have not. I do have the yellow and white wires from the 123 plugged into the ECU harness but I haven't confirmed that its is working. My noid light will be here this evening and I can verify the injectors are getting a signal from the ECU. If they are that would indicate the dizzy is triggering right? I don't want to move my dizzy ATM since I set it before with the webers and it was good then.

Hopefully your noid light can let you know if a signal is changing state. The 2 signals should go GND - 12V - GND ... very rapidly as the engine is turning. A volt meter may not work as it is good mainly for DC or signals that don't change like battery voltage.

Yes if the signals are not functioning correctly the injectors won't fire and your engine will do what you describe: Fire initially as the FP pressurizes the system when the key is turned on then the trigger points keep the fuel pump going.

[rjames]

As MJames stated, the MPS is critical.

Yes yours doesn't hold pressure, but it doesn't drop so fast that the car shouldn't at least start and run for a bit, albeit likely with a surging idle.

Did they rebuild the MPS such that you can make adjustments without opening it up?
If it were my car I'd try turning just the inner screw a quarter of a turn clockwise first, and if that didn't work, turn it the same amount the other way. Just keep track of how much you're moving it so you can get it back where it was if need be. Given your description, if the cause is the MPS being out of adjustment, a quarter to half turn one way or the other would either allow the car to idle, or rule out the MPS as the issue.

They did. I have access to the inner screw. The outer is marked with paint. I have debated adjusting the inner but will not be doing that until I have verified all injectors are firing and all measurements on the ECU pins are good.

How sensitive is that inner screw? If I move it could it cause damage to the engine?

You won't damage the engine. Adjusting the inner screw clockwise will lean out the mixture, counter-clockwise will richen the mixture. It's farily sensitive, which is why I only suggested 1/4-1/2 a turn, but you won't break anything if you go further. Note that you need the Tangerine Racing adjusting tool so that you don't also turn the outer screw that the inner screw sits in (not the outer screw you're talking about which is more commonly referred to as the full-load stop screw).