Running trouble

[czakky]

The pump sounds as good as it ever has. I'll measure there too.

 

Thanks again Roy.

We should have a Thanks Roy emoji

[docc]

Is it time to try the High Current OMRON relay in Position #5?

[czakky]

Tried fresh fuel, again. Checked TPS, again. No change.

 

What is wire 23 & 24? The ECU is grounded where?

 

I'm pretty sure it's running rich, would a bad ground effect that?

 

Getting bummed about this, it's just not making sense....

[Scud]

Is it time to try the High Current OMRON relay in Position #5?

 

Or at least rotate the relays you currently have and make sure they are all making good contact. I had three seemingly unrelated problems solved, as if by magic, by putting in new relays (but one that I removed was loose).

 

There will be a logical solution. Chances are it will seem obvious once we find it.

 

How's the condition of the rubber caps or hoses on the throttle bottle vacuum tubes? 

[docc]

 

Is it time to try the High Current OMRON relay in Position #5?

 

Or at least rotate the relays you currently have and make sure they are all making good contact. I had three seemingly unrelated problems solved, as if by magic, by putting in new relays (but one that I removed was loose).

 

There will be a logical solution. Chances are it will seem obvious once we find it.

 

Relays? magic? magic smoke?   . . . trickery?!? 

.  .  .  .  .   electrickery?

 

[czakky]

Fresh omrons last summer. I have tried rotating them and tightening bases. I'll try again though....

[czakky]

I found wire 23/24...

[Kiwi_Roy]

Too Rich,what would cause that?

                 Leaking injector, they would both have to leak

                                       Can you borrow a pair

                 ECU holding them open too long

                                     Temperature sensor showing cold - I think you said you measured those

                                      TPS way off - measure mV at idle, loosen it off and try it all over, it may run better at some point

                                        Bad map

                                                      This can happen if a download goes wrong, ask me how I know

                                       Any others?

 

 

 

                 Fuel pressure too high, forces more fuel through per opening time

                                      Regulator not plumbed right making the pump relieve at 75 psi not 45

                                                 This would show as a high current, measure Amps on relay 5 base 30 to 87 with the key Off (pump will run)

 

You say too rich based on what. exhaust?

 

Something else to try

Pull off each plug cap and measure resistance from cap to chassis, both sides should be the same, I'm guessing around 8K Ohms

[Chuck]

Have you actually tested the injectors? I don't remember reading that..

At this point, I would (although I don't like doing it) spray a little starting fluid in the intake to rule out ignition issues.

[Scud]

Ok just to re-iterate what she's doing.

Starts with a good amount of cranking and some throttle. Throttle held open partially she runs and purrs like a kitten albeit around 2k. Give her a bit of throttle she responds really well (when warmish) then it dies immediately when let off the throttle. Doesn't idle down revs don't "hang" just plain dies. Usually with a super loud backfire.

 

 

 

Too Rich,what would cause that?

                 Leaking injector, they would both have to leak

                                       Can you borrow a pair

                

 

 

Let's keep Czakky's description of the current problem (from 2-21 post above) in mind. What could account for the fact that it "purrs like a kitten" at 2,000 RPM, but has hard starts and shuts down off-throttle with a backfire? 

 

I don't know the answer - just trying to make sure we are asking the right questions.

 

I have a pair of injectors, which I would gladly send to Wisconsin in exchange for some cheese.      But... can injectors work well at some RPMs but not others? 

[Chuck]

 

 But... can injectors work well at some RPMs but not others?

My understanding is that the injectors are either on or off controlled by the computer. Digital stuff, don't ya know..

 

 What could account for the fact that it "purrs like a kitten" at 2,000 RPM, but has hard starts and shuts down off-throttle with a backfire?

That sounds to me like it's not getting enough fuel. I was asking if the spray pattern has been checked.

[czakky]

Chuck, i am leaning towards the injectors myself. What makes me think she's rich (I will gladly be wrong) is that my plugs when pulled have been black. The way I understand fueling is that at idle and low RPMs motors have to run somewhat rich, so maybe inconclusive. Also after she backfires there is most of the time a vapor coming out of the exhaust. Also also the way it revs and the way it reacts to throttle seems to my not wise mind that it is certainly not lean. It reacts somewhat smooth to inputs, revs dont creep and when it's running can smell fuel... a little.

[bbolesaz]

My $ is still on a timing problem.   As someone in the computer chip industry, I wouldn't rule out that the ECU itself has a failure.  Anyway to do an ECU swap with someone?

[MartyNZ]

...I am leaning towards the injectors myself. What makes me think she's rich (I will gladly be wrong) is that my plugs when pulled have been black...

Could the injectors be leaking? You can check this by releasing the velocity stacks off the throttle bodies,  and sliding them back into the airbox. Then you can use a mirror to look into the throttle bodies. With the throttle wide open, turn on the key and look for dribbling from the nose of the injector during the few seconds while the pump runs. 

[czakky]

So I basically did a high-tech version of what Marty recommended using a bore scope/inspection camera. Key on, prime pump, cycle kill-switch 3-4 times, nothing never a dribble of fuel from the injectors.

I know that I was told that there should be a squirt from the injectors at start up. Am I getting closer?