Leaking Fuel Injectors

Topic: Leaking Fuel Injectors (Read 3129 times) previous topic - next topic

Leaking Fuel Injectors

Reply #15 – June 15, 2012, 06:06:28 AM

The first thing i would do is swap injector 1 with 4. The 2.3 pairs 1&2 and 3&4. This way if the trouble happens again and moves you have a better idea of what is happening. Because of the paired injectors their may be an imbalance in that group. But as for it doing the same thing with the 3 suspected injectors is puzzling at best. But with a trouble like this all avenues must be tried and or tested. Also were the injectors bought new and the proper application used??? I would also change the coolant temp sender just for kicks. But swapping the injectors is in my view a good start. There may be an impedance issue between the injector number one and two as they are paired. Tough call on this one. The chances of another set of injectors doing the same thing is highly unlikely. You can also check the paired resistance readings with a good meter and compare the balance. But that is a long shot i guess. You would need a good FLUKE with low ohm stability to read it. Also the number one injector just might be the bad one. Replacing the three did the same thing. So my thinking is maybe the number one is bad. You might try installing one of the old injectors in position ONE just for kicks. Just a thought.

when you shut off your car, there is a time delay to when the eec relay turns off. during this time depending on the distributors position, there may be power applied to the same three injectors with a somewhat simulated ground being supplied to the injector

1&2 are grouped together. So it would be highly unlikely. Just me could be wrong again.

Leaking Fuel Injectors

Reply #16 – June 15, 2012, 05:10:35 PM

Quote from: softtouch;392342

Does that mean you got code 11 or no code at all?

I asked this to confirm that the software in the EEC is running and it is not in LOS mode.

I don't know how the intake is designed, so this may be a dumb question. If the front of the engine is a little higher than the rear, and the injectors pulsed while the engine was stopped, wouldn't the gas from the #1 injector run toward the rear?

To theorize a little more on the 5 second time period the EEC stays powered up after the engine shut down.
Something generating electrical noise being picked up by the PIP wire from the TFI causing the EEC to pulse the injectors. Maybe non-stock cooling fans still running after shut down. Maybe the fan wires are too close to the TFI wires.

Maybe a bad TFI module. If the PIP pulse voltage is not switching between good on and off levels, but is staying near the switching level. In my old computer trouble shooting days we called this being "on the hairy edge".

Leaking Fuel Injectors

Reply #17 – June 16, 2012, 05:44:08 PM

yeah, i see what you mean tom, odd problem for sure

Leaking Fuel Injectors

Reply #18 – June 16, 2012, 10:50:25 PM

I wonder if a bad or intermitant ground to the eec could effect the pip sensor, giving the engine the effect that it is turning over differently then normal. Thee evc4 system only uses pip input for rpm's right?

Leaking Fuel Injectors

Reply #19 – June 16, 2012, 10:59:31 PM

Once again if false trigger is the issue why is not the paired 1&2 having the same ISSUE??? Swap the injectors . Just me could be wrong again.

Leaking Fuel Injectors

Reply #20 – June 17, 2012, 12:44:17 PM

Well I will go do more testing today. But I probably wont find anything. I have not had the problem the last few days. And when the problem first started I replaced the fuel pressure regulator, fuel pump, and checked fuel pressure. The 3 injectors I replaced came off my spare motor. The motor ran just fine when I pulled it. So I would say the injectors where fine.

O and some one asked how I knew it was doing it. Normally it will start up just fine if it was running with in a hour of trying to start it again. If it sits any longer then that then it gets very hard to start. If I let it sit over night it more then likely wont start unless i pull the spark plugs and dry everything out..

I have been using the fuel cut off switch to kill the pump while the car is still running. Then before I go some where turn it back on and it starts just fine.

Leaking Fuel Injectors

Reply #21 – June 18, 2012, 01:41:40 PM

Quote from: softtouch;392428

I don't know how the intake is designed, so this may be a dumb question. If the front of the engine is a little higher than the rear, and the injectors pulsed while the engine was stopped, wouldn't the gas from the #1 injector run toward the rear?

Is this a dumb question?

From the 88 EVTM:
Fuel injectors on the 2.3L and 3.8L engines fire simultaneously (once for each crankshaft revolution).

Quote from: jonwayne1988;392559

Normally it will start up just fine if it was running with in a hour of trying to start it again. If it sits any longer then that then it gets very hard to start. If I let it sit over night it more then likely wont start unless i pull the spark plugs and dry everything out..

Well that seems to put the problem outside the 5 second EEC power down delay.
Put a volt meter on the red wire to the injectors. The battery voltage should go away about 5 seconds after key off.

If it doesn't, you are looking a either an ignition switch problem or an IRCM problem.

If it does, you don't have an electrical problem.

If it is intermittent, good luck catching it when it is failing.

Leaking Fuel Injectors

Reply #22 – June 18, 2012, 10:38:37 PM

humm,,, good points ,,, noid light on injector would be the right choice... never gave the ign sw a thought.

Leaking Fuel Injectors

Reply #23 – June 19, 2012, 07:42:41 PM

Just curious why would an ignition switch be an issue. And even if it was how do you explain number one not being effected. Unless the paired 1&2 are out of balance impedance wise. Or the paired 3&4 is out of balance and is effected by a BACK EMF!!! But why is it not effecting number one injector??? you might want to see if the injectors are leaking from a carbon build up on the PINTEL. You did say the injectors were USED!!

Leaking Fuel Injectors

Reply #24 – June 19, 2012, 08:46:09 PM

Quote from: TOM Renzo;392781

Just curious why would an ignition switch be an issue.

I asked him to check to see if the battery voltage was staying on the injectors with the key off. If it was, the ignition switch could be shorted and keeping the EEC power relay picked.

Quote

And even if it was how do you explain number one not being effected.

Tom he says it has to sit with the engine off for a long time before the problem shows up. If the front of the engine is higher would the gas from the #1 injector drain to the rear?

Leaking Fuel Injectors

Reply #25 – June 19, 2012, 09:57:17 PM

logical, the fuel rail does lean down in the rear

I suspect your nailing this one softtouch

in other words Tom, if the ign sw is off and is allowing the fuel pump to power down, if there is a defect in the ign sw keeping the EEC relay picked, then the injectors may have some degree of power irregardless of distributor position, the back two injectors sit lower,, with the fuel pump off **but** with fuel presure still on the tops of all the injectors,,, its possible the fuel pressure could bleed out the pental.

It took me a while before it clicked what softtouch was saying,, i get it now.

Leaking Fuel Injectors

Reply #26 – June 19, 2012, 10:07:06 PM

But if the injectors are not powered up they cant LEAK. And if they do without being powered up they need replacing So with all this technical mumbo jumbo The rail still has residual shut down pressure. So the fuel should leak past all the injectors not just 3. Even if the fuel rail was vertical the residual pressure would leak on all 4 if their was an electronic reason for it. Just me could be wrong!!

SWAP NUMBER 1 WITH NUMBER 4 And call it a day. This is so intermittent and random he needs proof of which injectors are actually leaking and he has this info. So by swapping them he can see if the trouble moves. SIMPLE AND takes like 10 minutes to do. just me and without swapping the injectors he is CHASING BALLOONS!!

Leaking Fuel Injectors

Reply #27 – June 19, 2012, 10:55:17 PM

ahh , yes but "what if the injectors are powered up" because the EEC relay is allowing it to be so due to a faulty ign sw?

Leaking Fuel Injectors

Reply #28 – June 19, 2012, 11:49:36 PM

An intermittent power condition to. The eec would cause a random miss in the engine, as well as the fuel pump. But where it continues running, I doubt that the fuel pump isn't supply fuel, at least enough to run all 4 injectors.

However, the car might run lean, and the eec could try to richen it up with longer injector pulses in an attempt to make the o2 read right, and putting a bunch of fuel in the cylinders. I don't think this wouldn't effect number 1 though, it should do all of them the same.

I agree with tom, swap number 1.

Have codes been pulled? What about a cylinder ballance test?

Leaking Fuel Injectors

Reply #29 – June 20, 2012, 05:51:10 AM

Quote from: jcassity;392806

ahh , yes but "what if the injectors are powered up" because the EEC relay is allowing it to be so due to a faulty ign sw?

Then all of them would FIRE!!! Unless number one is bad in a different way. Another words if number one is harder to fire it might NOT. So in reality he is looking for a common problem and we are dwelling on the issue that one injector is working properly and it is NOT!!!! Either swap number one or better yet install 4 new or different injectors!!!