Cold Start Issue 914-4, Admitting I'm stuck and asking for help Options

[Blue Lightning]

The MPS is the "Euro" version. I had a 043 and when I went by AA George Hussey recommended going with the 037 "Euro" part instead (and he had those, but no 043s). And yes, have vacuum tested the new part several times (IMG:style_emoticons/default/smile.gif)

So AA is back up to the old tricks? (IMG:style_emoticons/default/chair.gif)

Parts should not be mix and match. An 037 is not an 043 which is why it has a different part number.

The 037 is for the 73’. However, the 73 1.7L and the 2.0L use the same ECU and have some “tricks” played with the CHT and the calibration of the MPS to differentiate the calibrations to compensate for the 1.7L to 2.0L displacement change while using the same ECU. Both the MPS and the EcU for 73’ are different than the 76’ setup.

I assume you’re aware of the Brad Anders parts lists and the recommendation not to mix and match.


The MPS you have can be retuned but that isn’t part of what you bargained for. There is some bench calibration that can be done but per the guys (like Emery) that have retuned their MPS, you will really want to tune it on-road with a wide band air fuel meter.

I had seen Brad's parts page, but it didn't click that I may have ended up with the wrong part from AA.

The parts in the engine current are:
Engine: GC (correct for '76 2.0)
ECU: ??? (no sticker...only way I know is to open the case, which I didn't have a reason to do...yet)
Fuel Injectors: 0 280 150 038 (correct for '76 2.0)
CHT: resistance/temp curves are consistent with a 012 (correct for '76 2.0)
Thermotime: ??? (not cold enough out for me probably ever to need)
Deceleration Valve: ???
MPS: 037 (now incorrect)
Distributor: 011 / 205A (for '76 2.0 GA-series engine; correct for GC would be the 021 / 205B)

I've spent time looking at the differences between the 205A and 205B distributors, but have not found anything (this is the best reference I have found for the 205A: https://web.archive.org/web/20031213100259/...h/distrib.html)

I've read some stuff on retuning your MPS, but at some point you should just put in a megasquirt or something that and take advantage of a WB02 sensor and maybe have some closed-loop idle control (IMG:style_emoticons/default/smile.gif)

[Superhawk996]

Don’t sweat the distributor too much - the differences are related to the advance curves and what type of vacuum can they used.

Let’s try to power through the MPS for the moment. As Emery stated, the fact that it had an effect when you put vacuum on it is a great sign that when the low vacuum is addressed, things will get significantly better.

[emerygt350]

Don’t sweat the distributor too much - the differences are related to the advance curves and what type of vacuum can they used.

Let’s try to power through the MPS for the moment. As Emery stated, the fact that it had an effect when you put vacuum on it is a great sign that when the low vacuum is addressed, things will get significantly better.

Yes, at this point the mismatched ECU and such is not really going to mean much. When this is sorted it 'may' matter enough to require sorting. We will find out. The djet is actually a very robust system to faults. It won't run perfectly, but it should get you home.

[ctc911ctc]

I watched the video:

1. Once it starts it runs good
2. Takes too long to start - Spark or Fuel?
3. Seat Buzzer - HHHHhhhhmmmmmmmmmmmm
4. Ignition Switch at the key?

Here is my experience - I had a 1.7 that would run fine and then not start, I was 20, and it drove me crazy - turned out the ignition switch was intermittent - know problem. Every 914 I have owned since I change the ignition switch - FIRST THING

I would:

1. Eliminate the seat belt buzzer and all of that circuitry - many guides as to how this is done
2. As you are cranking - check the ignition switch circuit at the junction box (Yellow wire?) for 12ish volts. If this is solid 12v while you have the long cranking, I have no idea, however, if you are long cranking and have no 12v - the switch behind the key is fried

Question: how many of us on this thread have experienced this before???? (IMG:style_emoticons/default/dry.gif)


Oh, as to the plenum leaks - fix them - this will be a constant cause of uncertainty - the entire DJet system is an open-loop control system based on differential vacuum between the high vacuum (plenum) and low vacuum (air cleaner area) system - The Djet system does not handle control variations in vacuum very well, fix the vacuum and the control equation is at least no longer a variable.

Still no bueno. Added a jumper cable between the battery negative terminal and the engine, plugged off the cold-start injector fuel line, and plugged the vacuum lines on the decell valve. None of this seems to have made a change.

Video of run at https://www.youtube.com/watch?v=9xbr0VjFFkE
~1:20 adjusted the idle air bleed screw. At the end, it is backed out so far it is almost falling out of the throttle body, but I get the idle up to 1400 RPM.
~2:10 checked fuel pressure (30 psi)
~2:15 couple shots of starting fluid, which almost kill engine
~4:20 rev up to ~4k RPM
~6:30 starts to die (AAR fully closed at this point?)
~7:45 added the PO's air filter, which make things worse

Note that I cranked the engine for a minute or two before starting the recording, then pulled a spark plug (which looked the same as the previous pictures...no obvious fuel or oil fouling).

[Blue Lightning]

I watched the video:

1. Once it starts it runs good
2. Takes too long to start - Spark or Fuel?
3. Seat Buzzer - HHHHhhhhmmmmmmmmmmmm
4. Ignition Switch at the key?

Here is my experience - I had a 1.7 that would run fine and then not start, I was 20, and it drove me crazy - turned out the ignition switch was intermittant - know problem.

I would:

1. Eliminate the seat belt buzzer and all of that circuitry - many guides as to how this is done
2. As you are cranking - check the ignition switch circuit at the junction box (Yellow wire?) for 12ish volts. If this is solid 12v while you have the long cranking, I have no idea, however, if you are long cranking and have no 12v - the switch behind the key is fried

Question: how many of us on this thread have experienced this before???? (IMG:style_emoticons/default/dry.gif)


Oh, as to the plenum leaks - fix them - this will be a constant cause of uncertainty - the entire DJet system is an open-loop control system based on differential vacuum between the high vacuum (plenum) and low vacuum (air cleaner area) system - The Djet system does not handle control variations in vacuum very well, fix the vacuum and the control equation is at least no longer a variable.

Still no bueno. Added a jumper cable between the battery negative terminal and the engine, plugged off the cold-start injector fuel line, and plugged the vacuum lines on the decell valve. None of this seems to have made a change.

Video of run at https://www.youtube.com/watch?v=9xbr0VjFFkE
~1:20 adjusted the idle air bleed screw. At the end, it is backed out so far it is almost falling out of the throttle body, but I get the idle up to 1400 RPM.
~2:10 checked fuel pressure (30 psi)
~2:15 couple shots of starting fluid, which almost kill engine
~4:20 rev up to ~4k RPM
~6:30 starts to die (AAR fully closed at this point?)
~7:45 added the PO's air filter, which make things worse

Note that I cranked the engine for a minute or two before starting the recording, then pulled a spark plug (which looked the same as the previous pictures...no obvious fuel or oil fouling).

The safety relay has been removed and the heavy yellow wires connected permanently. The seatbelt buzzer is the only part left. This was all done by one of the PO's, and the car was running with this so am reluctant to touch it at this time.

I have thought about replacing the ignition switch, but haven't found anything that doesn't work that it controls. The car does start, and even try to start while cranking early.

[emerygt350]

You should check the voltage to the coil while cranking and when it is running. But first....

[Blue Lightning]

The parts in the engine current are:
Engine: GC (correct for '76 2.0)
ECU:0 280 000 052
Fuel Injectors: 0 280 150 038 (correct for '76 2.0)
CHT: resistance/temp curves are consistent with a 012 (correct for '76 2.0)
Thermotime: ??? (not cold enough out for me probably ever to need)
Deceleration Valve: ???
MPS: 037 (now incorrect)
Distributor: 011 / 205A (for '76 2.0 GA-series engine; correct for GC would be the 021 / 205B)

I've spent time looking at the differences between the 205A and 205B distributors, but have not found anything (this is the best reference I have found for the 205A: https://web.archive.org/web/20031213100259/...h/distrib.html)

I've read some stuff on retuning your MPS, but at some point you should just put in a megasquirt or something that and take advantage of a WB02 sensor and maybe have some closed-loop idle control (IMG:style_emoticons/default/smile.gif)

Confirmed ECU is correct for the car

[emerygt350]

I think everything can be back burnered until you get a compression test done or if you feel like it, check the valves. What method did you use to set them?

[Superhawk996]

Confirmed ECU is correct for the car

(IMG:style_emoticons/default/smilie_pokal.gif) worth knowing that information.

[Blue Lightning]

I think everything can be back burnered until you get a compression test done or if you feel like it, check the valves. What method did you use to set them?

I did compression in December shortly after I bought the car (trying to understand what I bought) and the numbers were pretty good (130-140 psi cold). Are you suggesting doing it again?

One of the issues the PO disclosed about the car was that several of the pushrod tubes were leaking, so I tackled this right away. This required removal of a fair amount of the valvetrain, so I set the clearances after this. I had just re-marked the timing marks on the fan impeller and on the flywheel (added paint to the existing factory scribe marks), so used these to find TDC when doing the adjustment. Then feeler gauges and patience. (IMG:style_emoticons/default/unsure.gif)

[Blue Lightning]

Here is a video of mine at cold start this morning. You can see how the vacuum starts and where it is after a minute and a half. The video starts maybe 5 seconds after I started the car. Didn't think of it till I started otherwise I would have recorded that for you too.
https://www.youtube.com/shorts/-owQvPa68sc
Don't mind the wonky AFR, it takes forever for that thing to kick on.

Here is where all the needles are after my 1 mile commute to work.

Do you have a deceleration valve in your car still? Reading https://members.rennlist.com/pbanders/DJetP...tm#troubleshoot in the Deceleration Valve section, it seems like this should limit the vacuum to ~17 psi?

[emerygt350]

Here is a video of mine at cold start this morning. You can see how the vacuum starts and where it is after a minute and a half. The video starts maybe 5 seconds after I started the car. Didn't think of it till I started otherwise I would have recorded that for you too.
https://www.youtube.com/shorts/-owQvPa68sc
Don't mind the wonky AFR, it takes forever for that thing to kick on.

Here is where all the needles are after my 1 mile commute to work.

Do you have a deceleration valve in your car still? Reading https://members.rennlist.com/pbanders/DJetP...tm#troubleshoot in the Deceleration Valve section, it seems like this should limit the vacuum to ~17 psi?

That would cause my idle to skyrocket. My engine produces 'extra special' amounts of vacuum. My decel keeps my vacuum below 23 on overrun and that is about all it does. The decel shouldn't be setting idle vacuum, it would only function as an AAR. Why is my vacuum so high? No clue (freshly rebuilt, larger displacement, very careful tuning and timing)... However, not many people run vacuum gauges on their dash so how many other 2056s with my compression ratio and a stock cam are also at these low pressures? Hard to know. Made tuning the MPS fun.


OP: Did you check the compression after the valve adjustment?

I prefer (just personal choice) the crusty method of valve adjustment. No need to look at the flywheel or get out from under the car.
Have one wheel on the car, block the other wheel from moving, and put it in 5th gear. Rotate the wheel until a valve (let's say the one closest to the driver is completely compressed. When it is you know the opposite valve (closest to the passenger) is completely loose. Set that loose valves lash. Rinse and repeat all the way around. No guessing about what cylinder is at what stroke etc. Just methodical and no getting up and down. What clearances did you use? And just a thought, are you sure you have flat tappets? Stranger things have happened.

[emerygt350]

Here is a nice clear guide on what a vacuum gauge can help you diagnose. Valve issues is near the bottom.

https://www.onallcylinders.com/2015/05/08/q...ngine-problems/

[Ron914]

Here is a nice clear guide on what a vacuum gauge can help you diagnose. Valve issues is near the bottom.

https://www.onallcylinders.com/2015/05/08/q...ngine-problems/

I have been following this post also .Thanks for the information on the gauge Emery , I think I need to look into this later down the road
@ Blue Lightning good luck with solving your 2.0L D-Jet issues we are chasing different but similar problems . @emerygt350 and @Suoerhawk996 seem to have a lot experience with these issues and this forum are our best source of information to resolve are issues .

[Blue Lightning]

Did you check the compression after the valve adjustment?

I prefer (just personal choice) the crusty method of valve adjustment. No need to look at the flywheel or get out from under the car.
Have one wheel on the car, block the other wheel from moving, and put it in 5th gear. Rotate the wheel until a valve (let's say the one closest to the driver is completely compressed. When it is you know the opposite valve (closest to the passenger) is completely loose. Set that loose valves lash. Rinse and repeat all the way around. No guessing about what cylinder is at what stroke etc. Just methodical and no getting up and down. What clearances did you use? And just a thought, are you sure you have flat tappets? Stranger things have happened.

No haven't checked compression again after adjustment. I added a compression check to my list after the valve adjustment this weekend.

The valve adjustment method you did is similar to mine, except I look at the TDC and 180-degree marks on the flywheel while under the car. No need to get out from under the car, as long as you check the distributor before you start!

[emerygt350]

Did you check the compression after the valve adjustment?

I prefer (just personal choice) the crusty method of valve adjustment. No need to look at the flywheel or get out from under the car.
Have one wheel on the car, block the other wheel from moving, and put it in 5th gear. Rotate the wheel until a valve (let's say the one closest to the driver is completely compressed. When it is you know the opposite valve (closest to the passenger) is completely loose. Set that loose valves lash. Rinse and repeat all the way around. No guessing about what cylinder is at what stroke etc. Just methodical and no getting up and down. What clearances did you use? And just a thought, are you sure you have flat tappets? Stranger things have happened.

No haven't checked compression again after adjustment. I added a compression check to my list after the valve adjustment this weekend.

The valve adjustment method you did is similar to mine, except I look at the TDC and 180-degree marks on the flywheel while under the car. No need to get out from under the car, as long as you check the distributor before you start!

I would do the compression check next.

And you are certain no one upgraded your car to hydraulic lifters?

[Blue Lightning]

And you are certain no one upgraded your car to hydraulic lifters?

I'm the 4th owner, and I have a binder of records, but I am not "certain". Based upon the records I have, I believe the car only has ~83k miles, and the engine has never been out. This is also consistent with what the engine looks like (all the missing grommets and seals).

While not impossible, I would be surprised if there were hydraulic lifters.

[emerygt350]

Ok, just one of those assumptions hawk keeps going on about. It isn't common but it does happen.

[Ron914]

I like you believe I have an original survivor car with only 95,000 miles but I am learning along the way that with these cars and all the hands that have touched them in their life it's hard to tell sometime . Hence you photo of you distributor my photo of mine shows a different number and the A vs B was lined out along with number 2 021
I hope we both do.

[emerygt350]

At least they weren't as drunk as they were when they built mine.