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

[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

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.

I do have the list of compatible components, I'll double check that mine match. I did test the wiring harness from the ecu to the cht.

Jon

[ConeDodger]

Is the wire from your CHT sensor broken or disconnected? (IMG:style_emoticons/default/sad.gif)

[Jon H.]

Is the wire from your CHT sensor broken or disconnected? (IMG:style_emoticons/default/sad.gif)

Nope, it all checks out. I wish it was something as simple as that.

Jon

[914_teener]

I agree with the suggestions about the MPS and can relate about what happened to me that was particularly frustrating:

My car had similar symptoms....sometimes flooding....sometimes running.

I went to Harbor Freight and got the Actron vacuum gauge just to test it.....statically it tested out fine....HOWEVER...I noticed that it would leak down slowly just barely within the time limits on the Anders site.

Over the course of about a month.....it got worse. This time I tested it again and "no go". Decided on a new one.

I took the original apart and discovered it had split. I surmised that the diaphragm had split slightly and then progressed to the extent later that is just wouldn't hold vacuum at all.

So when you say somebody else tested it.....make sure the criteria of the test. It must hold the vacuum over time.

Secondly after replacing the MPS it would run....but still running uber rich...by then....it was WTF.....I just happened to have a spare ECU I had picked up....swapped it out...all has been good for 3 years now.


So be prepared for several things (meaning the FI components)....and that given confidence in your own self that the solution will be found, given that you need to be methodical in your approach. There is nothing like a good running FI system...in my opinion.

Some of the best advice I have received...and confidence...has been from folks here.

You have to be in the frame of mind to receive it. What you choose to do with it is up to you.

[Jon H.]

I agree with the suggestions about the MPS and can relate about what happened to me that was particularly frustrating:

My car had similar symptoms....sometimes flooding....sometimes running.

I went to Harbor Freight and got the Actron vacuum gauge just to test it.....statically it tested out fine....HOWEVER...I noticed that it would leak down slowly just barely within the time limits on the Anders site.

Over the course of about a month.....it got worse. This time I tested it again and "no go". Decided on a new one.

I took the original apart and discovered it had split. I surmised that the diaphragm had split slightly and then progressed to the extent later that is just wouldn't hold vacuum at all.

So when you say somebody else tested it.....make sure the criteria of the test. It must hold the vacuum over time.

Secondly after replacing the MPS it would run....but still running uber rich...by then....it was WTF.....I just happened to have a spare ECU I had picked up....swapped it out...all has been good for 3 years now.


So be prepared for several things (meaning the FI components)....and that given confidence in your own self that the solution will be found, given that you need to be methodical in your approach. There is nothing like a good running FI system...in my opinion.

Some of the best advice I have received...and confidence...has been from folks here.

You have to be in the frame of mind to receive it. What you choose to do with it is up to you.

I am fairly committed to get this thing fixed just because put on carbs will be like a cop out. I wish I had a bunch of spare FI parts that I could swap around but I don't. I'm also holding out on buying used new stuff since it can get costly if it the new parts I replace don't solve the problem.

Thanks for the encouraging words.

Jon

[Spoke]

You mentioned that the CHT measured 2500 ohms instead of 1300 ohms.

This will cause the engine to run rich. Not sure if this is your entire issue but it isn't right.

Go to Radio Shack or equivalent and get a 2500 ohm resistor (any power level) and connect it from the CHT connector to ground. When paralleled with the 2500 ohm CHT the 2 will measure 1/2 that value or 1250 ohms.

Try that and see if it runs.

[Jon H.]

You mentioned that the CHT measured 2500 ohms instead of 1300 ohms.

This will cause the engine to run rich. Not sure if this is your entire issue but it isn't right.

Go to Radio Shack or equivalent and get a 2500 ohm resistor (any power level) and connect it from the CHT connector to ground. When paralleled with the 2500 ohm CHT the 2 will measure 1/2 that value or 1250 ohms.

Try that and see if it runs.

Or what about a 1200 ohm one in series?

Jon

[r_towle]

get a 0-3k variable potentiometer.
Its a volume control switch at Radio shack.

Use that to set the motor up...inline with the CHT.

Once you are done and the car runs right, measure the resistance across the POT, and replace it with the exact resistor you need.

Way faster than guessing.

Rich

[Spoke]

You mentioned that the CHT measured 2500 ohms instead of 1300 ohms.

This will cause the engine to run rich. Not sure if this is your entire issue but it isn't right.

Go to Radio Shack or equivalent and get a 2500 ohm resistor (any power level) and connect it from the CHT connector to ground. When paralleled with the 2500 ohm CHT the 2 will measure 1/2 that value or 1250 ohms.

Try that and see if it runs.

Or what about a 1200 ohm one in series?

Jon

Do you mean one 1200 ohm resistor instead of the CHT sensor? Yes.

If you add a resistor to the CHT, then you want it in parallel with the CHT, not in series. Resistors in series add; resistors in parallel reduce the resistance. You want to reduce the resistance.

Series resistance: Rtotal = R1 + R2

Parallel resistance: Rtotal = R1 x R2 / (R1 + R2)

[Jon H.]

You mentioned that the CHT measured 2500 ohms instead of 1300 ohms.

This will cause the engine to run rich. Not sure if this is your entire issue but it isn't right.

Go to Radio Shack or equivalent and get a 2500 ohm resistor (any power level) and connect it from the CHT connector to ground. When paralleled with the 2500 ohm CHT the 2 will measure 1/2 that value or 1250 ohms.

Try that and see if it runs.

Or what about a 1200 ohm one in series?

Jon

Do you mean one 1200 ohm resistor instead of the CHT sensor? Yes.

If you add a resistor to the CHT, then you want it in parallel with the CHT, not in series. Resistors in series add; resistors in parallel reduce the resistance. You want to reduce the resistance.

Series resistance: Rtotal = R1 + R2

Parallel resistance: Rtotal = R1 x R2 / (R1 + R2)

Right! totally didn't think that out. Of course it adds resistance when in series. I did take electrical in high school, and I got an A!

[tumamilhem]

get a 0-3k variable potentiometer.
Its a volume control switch at Radio shack.

Use that to set the motor up...inline with the CHT.

Once you are done and the car runs right, measure the resistance across the POT, and replace it with the exact resistor you need.

Way faster than guessing.

Rich

I think I need to follow your suggestion with my car, but I don't understand anything electrical.

[Jon H.]

Well I solved the flooding issue (IMG:style_emoticons/default/smile.gif) I had two wires break off the connector a while back and I soldered them back on but they were put back into the wrong spots (although I marked them (IMG:style_emoticons/default/dry.gif) ). But now that I have that fixed I have no injector pulse (I used a node light to check that). I did read that a faulty MPS would cause this. I do have a line on some ECU's and MPS's that are local (Cool914) and I will give them a try and see if it fixes this problem. I'm sure its not the dist. since it worked when I left town and now it doesn't since I fixed the MPS wires. I also tested the whole wiring harness for continuity and tested the Ohms for the MPS at the ECU. I did drop the MPS on the shop floor tonight?

One question though, would the mismatched wires cause the MPS to become inoperable? The readings across the primary and secondary coil are still both within spec.

Regards'

Jon

[914_teener]

Not sure but if this is the case but it is possible to short out a portion of the ECU....so I am not sure which wires you crossed....MPS? Which ones?

Try to get a spare ECU for your motor and see if that does it.

[914_teener]

.....oh and if you have a problem with wires breaking off.....you need a new harness.

I didn't mess around trying to solve problems that kept reappearing. I called Bowlsby and got a new harness.

[r_towle]

put a noid light on the wires from the distributor for the fuel injection timing....see if that signal is working properly.

Rich

[Jon H.]

It is now fixed (IMG:style_emoticons/default/piratenanner.gif) I assumed that since the two outside wires on the MPS went to the appropriate places then the two inside ones should be fine(since the plug can be turned around and still work). Well I was wrong, the two inside ones should also be wired as per the OEM wiring diagram.

Regards'

Jon