DJet won't stop flooding on start up?, flooding is fixed, now no injector pulse Options

[Jon H.]

I have 1973 2.0l with djet and it will flood and not start. I bought the motor from a friend of mine and I heard it run before I bought it .

Now this thing will not run long enough so i can figure out what is going on. I have already done two oil changes to get ride of the fuel in the oil. This is starting to get expensive.

I have checked the CHTS it is good. The MPS coil values are within spec and the MPS also holds vacuum, some what. Fuel pressure is 30-29 psi while cranking.

I cranked the engine for 15s and the Fuel injectors fuel volume measured between 4 and 6 tsp's per injector(is this good)??. I checked the valve adjustment, all is good. I unplugged the cold start valve and capped it off so i know its not that. If i pull the injector plugs it will start to kick, run a bit and burn off the excess fuel and then not run(because the unplugged injector).
I'm sure it's an ignition problem.

How can I check my timing and dwell with a motor that wont run? it will run after waiting 12 hours then it floods and dies.

This is not an engine that is running rich but an engine that won't run because of a rich condition. I raise my fists in frustration!!

I'm sure this is an ignition problem and not a DJet issue.

I have tried to figure this out since May but have been unsuccessful.

Regards'

Jon (IMG:style_emoticons/default/dry.gif) (IMG:style_emoticons/default/dry.gif)

[JamesM]

1. MPS holding vacuum "somewhat" might not be good enough.

2. Did you check the CHT resistance at the ECU connector? infinite resistance (broken wire) will cause a super rich condition that makes it pretty much impossible to start without holding open the throttle.

if none of the injectors are leaking and you are super rich, these are your prime suspects, swap out the MPS for a known good one and see if it helps.

[mankowski]

From Brad Anders' website:

Injector flow rate data (courtesy of Roland Kunz):

Yellow (1.7L) - 265 cc/min @ 2.0 Bar, 3V, 0.15 mm ± 0.05 mm lift
Green (2.0L) - 380 cc/min @ 2.0 Bar, 3V, 0.15 mm ± 0.05 mm lift

So, your output is well within this rate, quite a bit lower, in fact.

The MPS sounds bad.

MPS Vacuum leaks: Depending on the extent of the leak, the car can run
slightly rich to very rich across the entire load range.

You can make an approximate setting of your ignition timing statically. Here is a good description, which although written for the 911 is largely the same for our 914s. Once you get it close enough statically, it should run well enough for you to set timing dynamically. Of course, your valves need to be correctly adjusted first, and you didn't mention them, but I am guessing you think they have not changed substantially since you ran the motor previously.

Do you have the correct CHTS for the motor (with correctly functioning resistor, MPS and ECU)? What is the resistance shown by your test to be 'good'? Finally, have you cleaned and checked the functioning of the trigger points in the distributor housing?

Check these additional things and report back on what you find. Hang in there!

[mankowski]

Here is the reference to the static timing description that I left out of the last post.

http://www.pelicanparts.com/techarticles/9...atic_timing.htm

Also, should have been Paul Anders.

- Eric

From Brad Anders' website:

Injector flow rate data (courtesy of Roland Kunz):

Yellow (1.7L) - 265 cc/min @ 2.0 Bar, 3V, 0.15 mm ± 0.05 mm lift
Green (2.0L) - 380 cc/min @ 2.0 Bar, 3V, 0.15 mm ± 0.05 mm lift

So, your output is well within this rate, quite a bit lower, in fact.

The MPS sounds bad.

MPS Vacuum leaks: Depending on the extent of the leak, the car can run
slightly rich to very rich across the entire load range.

You can make an approximate setting of your ignition timing statically. Here is a good description, which although written for the 911 is largely the same for our 914s. Once you get it close enough statically, it should run well enough for you to set timing dynamically. Of course, your valves need to be correctly adjusted first, and you didn't mention them, but I am guessing you think they have not changed substantially since you ran the motor previously.

Do you have the correct CHTS for the motor (with correctly functioning resistor, MPS and ECU)? What is the resistance shown by your test to be 'good'? Finally, have you cleaned and checked the functioning of the trigger points in the distributor housing?

Check these additional things and report back on what you find. Hang in there!

[Mblizzard]

Sorry to suggest things you have likely all ready done but we just got to the party.

Working with you on it being a timing issue. What did you change since you heard it run?

Assuming you did a basic tune up and you did not remove the dizzy from the car.

Go through the process of finding TDC and verifying it is at TDC by confirming the piston is at the top in #1 cylinder. Remuneration the timing marks on the impeller make 2 revs to one of the dizzy.

At TDC, the rotor should be pointing to #1 which should be toward the rear of the car. If it is not then you are not at TDC or your wires are incorrect. Since you have verified TDC by the presence of the piston at the top of #1 your next step is to arrange the plug wires on the cap in the correct firing order starting with #1 lining up with the location of the rotor at TDC. The car should run if this is correct. If it wants to start and is still flooding, pull the fuse on the fuel pump and see it will start using starting fluid.

If you did remove the dizzy you will also want to confirm that you did not move the drive gear. Look for the thread referring to 12 degrees.

This should get you the information to either keep chasing a timing problem or move on to the FI system.

Sorry if I am only suggesting things you have done already.

[Jon H.]

Thanks for all the replies.

1. The CHTS is the correct one. I didn't check the wire to the ECU though.

2. I re-did the valves last night just to be sure.

3. I will try and get a good MPS today.

4. The fuel pressure holds pressure quite well, no leaky injectors.

5. It has ran after sitting all night but after about a minute it will flood.

6. Can you put the distributer in wrong as mentioned above? I did remove it when I re-sealed the engine. I didn't remove or loosen the lock collar though.

I will be gone away from the house until Sunday so then I'll try the items mentioned above.

Regards'

Jon

[Jon H.]

The kids are still sleeping so I checked continuity from the CHTS to the ECU and the MPS to the ECU, all is good. Fuel system still has 10 psi, which is surprising.

Jon

[r_towle]

did you remove the fuel supply line from the cold start injector?
They have been known to get stuck in the open position, so if you reroute the fuel line around the cold start injector, you guarantee to get it out of the loop.

You will need either a new fuel line, or a male male connector to do this.

Unplugging the electrics from the cold start injector will not shut it off.

If you have already done this and its still flooding, its most likely the MPS.

Rich

[sean_v8_914]

yeah. what Rich said

[Dave_Darling]

Also, should have been Paul Anders.

He goes by "Brad Anders".


I had similar symptoms once that turned out to be a problem with the ECU. In fact, I even wound up hydro-locking the motor with fuel, once!! It took me a long time to track that one down, since the ECUs are generally quite robust.

--DD

[r_towle]

Also, should have been Paul Anders.

He goes by "Brad Anders".


I had similar symptoms once that turned out to be a problem with the ECU. In fact, I even wound up hydro-locking the motor with fuel, once!! It took me a long time to track that one down, since the ECUs are generally quite robust.

--DD

Interesting to hear of another ECU going south.

Seems the soldering process changed in the early 80's to a worse process.
Some sort of flow process that made more cold joints than not.

84 911 ECU needed to be redone
91 BMW light ECU needed to be redone.

Never had to do either a 914 or Volvo p1800 ECU's from the 70's

Rich

[toadman]

Also, should have been Paul Anders.

He goes by "Brad Anders".


I had similar symptoms once that turned out to be a problem with the ECU. In fact, I even wound up hydro-locking the motor with fuel, once!! It took me a long time to track that one down, since the ECUs are generally quite robust.

--DD

This happened to me, too, except that I didn't have the hydro-locking. I flooded the engine a few times and was stranded by the side of the road a few times before I solved this one. I was troubleshooting this problem off and on for several months before I accidentally brushed up against the ECU with my arm and felt a hot spot on the metal case. I thought "that's not good" so I changed the ECU and everything was fine.

[tumamilhem]

I am having the same issues you are right now. Unfortunately, I'm no mechanic, so it's been difficult for me to figure this out. Reading the suggestions on your post is even more confusing to me, but probably relevant to my issue.

I've received lots of good suggestions on my post, same issues as yours. Maybe they will be of assistance to you as well. Good luck! Here's the link:

http://www.914world.com/bbs2/index.php?act...=2&t=216237

[Jon H.]

I am having the same issues you are right now. Unfortunately, I'm no mechanic, so it's been difficult for me to figure this out. Reading the suggestions on your post is even more confusing to me, but probably relevant to my issue.

I've received lots of good suggestions on my post, same issues as yours. Maybe they will be of assistance to you as well. Good luck! Here's the link:

http://www.914world.com/bbs2/index.php?act...=2&t=216237

Isn't this painful? I do have a bit of mechanical skill but that doesn't make this easier. I have been following your thread and trying some of the suggestions that have been made. Hopefully we will get this figured out. I'm sure we will!

Jon

[Jon H.]

I had mike at Mikes 914's double check my mps, he said it was good and wouldn't be the issue. I now know that the chts is the wrong one. The motor and all associated electronics are from MY 73' so my chts should be reading 1300 ohms vice the 2500 or so that it is currently reading (Is that 1300 reading at the usual 68 degrees?) I should have the chts ending in #017 and not #003. This is still surprising since the motor ran before removal.

Now since these are NLA I guess I need to install a resistor? Will this work as well as trying to source the correct chts?

Jon

[Java2570]

How is your injection wiring harness? If the engine ran prior to you putting it in your car and now you are having these flooding issues, I would think it's a harness issue.
Even if your MPS tests good, a bad wire in your harness could tell it otherwise.
I ended up sending my harness to Jeff Bowlsby and he found it was not fixable.
Jeff makes great replacement harnesses and it made a huge difference in how my car ran. Or you could also try swapping MPS & ECU with known good units to see if it makes a difference but it really sounds like wiring is causing your components to ask for too much fuel.

[Jon H.]

How is your injection wiring harness? If the engine ran prior to you putting it in your car and now you are having these flooding issues, I would think it's a harness issue.
Even if your MPS tests good, a bad wire in your harness could tell it otherwise.
I ended up sending my harness to Jeff Bowlsby and he found it was not fixable.
Jeff makes great replacement harnesses and it made a huge difference in how my car ran. Or you could also try swapping MPS & ECU with known good units to see if it makes a difference but it really sounds like wiring is causing your components to ask for too much fuel.

I have tested the the mps, chts and injection portions of the harness, I unplugged the cold start fuel line and capped it off. I will check the rest of the harness when I get home on Sunday. I will also try grounding the chts to the engine. I have know access to other 2.0l FI parts here in ottawa.

Thanks for the suggestions.

Jon

[Bartlett 914]

I had mike at Mikes 914's double check my mps, he said it was good and wouldn't be the issue. I now know that the chts is the wrong one. The motor and all associated electronics are from MY 73' so my chts should be reading 1300 ohms vice the 2500 or so that it is currently reading (Is that 1300 reading at the usual 68 degrees?) I should have the chts ending in #017 and not #003. This is still surprising since the motor ran before removal.

Now since these are NLA I guess I need to install a resistor? Will this work as well as trying to source the correct chts?

Jon

Make sure you have the correct components. Brad Anders site shows the correct combination. There was a big change between 73 and 74. The MPS, ECU and the CHT must be matched. 73 used a balast resistor (resistor in series with the CHT). in 74, this was removed and the ECU is different. Make sure the CHT is actually connected to the ECU. This wire can be broken. You can also wire in a pot in place of the CHT. Near 100 ohms when warm. Higher resistance = richer condition across the full operating range. The pot on top of the ECU is for the idle circuit mixture.

[JamesM]

I had mike at Mikes 914's double check my mps, he said it was good and wouldn't be the issue. I now know that the chts is the wrong one. The motor and all associated electronics are from MY 73' so my chts should be reading 1300 ohms vice the 2500 or so that it is currently reading (Is that 1300 reading at the usual 68 degrees?) I should have the chts ending in #017 and not #003. This is still surprising since the motor ran before removal.

Now since these are NLA I guess I need to install a resistor? Will this work as well as trying to source the correct chts?

Jon

The higher resistance on the CHT would cause you to go rich but I don't know if it would cause it to go so rich it wont run. As you have found the 73 CHT is near impossible to find, your best bet is to get a 74 ECU and MPS(or just adjust your current MPS to match).

Do not get discouraged, these systems are not very complex. If you have already confirmed that the 5th injector is not leaking (which it sounds like from your rail holding pressure that it is not) then there is only a limited number of things it could be.

Also, just because your MPS holds a vacuum does not mean its good. Unless you have taken it and ran it in another car without issue, I would not count it out as a suspect. I saw this exact thing on a 73 1.7 a few weeks ago, car was running great then all of a sudden it was super rich and wouldn't idle. Checked the MPS and leaked down faster then it should but not fast enough that you would think it was a problem, everything else checked out though so I let him borrow one of my spares and sure enough, car would idle again.

[Jon H.]

I had mike at Mikes 914's double check my mps, he said it was good and wouldn't be the issue. I now know that the chts is the wrong one. The motor and all associated electronics are from MY 73' so my chts should be reading 1300 ohms vice the 2500 or so that it is currently reading (Is that 1300 reading at the usual 68 degrees?) I should have the chts ending in #017 and not #003. This is still surprising since the motor ran before removal.

Now since these are NLA I guess I need to install a resistor? Will this work as well as trying to source the correct chts?

Jon

The higher resistance on the CHT would cause you to go rich but I don't know if it would cause it to go so rich it wont run. As you have found the 73 CHT is near impossible to find, your best bet is to get a 74 ECU and MPS(or just adjust your current MPS to match).

Do not get discouraged, these systems are not very complex. If you have already confirmed that the 5th injector is not leaking (which it sounds like from your rail holding pressure that it is not) then there is only a limited number of things it could be.

Also, just because your MPS holds a vacuum does not mean its good. Unless you have taken it and ran it in another car without issue, I would not count it out as a suspect. I saw this exact thing on a 73 1.7 a few weeks ago, car was running great then all of a sudden it was super rich and wouldn't idle. Checked the MPS and leaked down faster then it should but not fast enough that you would think it was a problem, everything else checked out though so I let him borrow one of my spares and sure enough, car would idle again.

I'll try and eliminate the chts first then try and source another ecu and mps. That does seem like a good solution. There is no one near me to swap out components so it makes this more difficult to diagnose.

Jon