2G No fuel in #3 or #4

[Jacob_Barnes520GST]

Heres an interesting one, I replaced my throttle body today with new gaskets, and all of a sudden I have no fuel in 3 and 4. I pulled the plugs and 1 and 2 were wet but 3 and 4 were dry. Can anyone give me an idea why the injectors aren’t pulsing? The car will try to start after the first few cranks but then won’t do anything

 

[92AWDHX40]

Sounds like you have a bad connection check for power at the injectors with a volt meter, to see if you have power to them. Sounds random if the others are working and you just did a gasket change.

 

[Jacob_Barnes520GST]

Will do. I checked everything already and everything looks good. I haven’t had anything injector related off before, so I’ll go over everything again.

 

[motomattx]

A couple of connectors will interchange, if I remember right the a/c connector and the coil pack plug interchange or it might be the cam/crank sensor and a/c connector, in any event go back and check those if you had them off.

 

[luv2rallye]

Also the CAS controls when injectors fire so check it's connector pins.

 

[Jacob_Barnes520GST]

I have been looking this morning, and I found that my knock sensor wire came loose from the main harness plug. Would this cause a no start issue?

 

[Jacob_Barnes520GST]

Knock sensor won’t cause no start. Fixed plug and same symptoms

 

[Jacob_Barnes520GST]

Checked CAS and everything checked out. What’s around the throttle body that would make the injectors not pulse? I worked only in that area

 

[92AWDHX40]

Nothing unless you have bad wiring, if you have two that works but the others don't, sounds like wiring issues, could be a gremlin lurking around.

 

[Jacob_Barnes520GST]

I’ve traced the wire loom that’s below the tb and all the wires that go to the injectors and haven’t found anything. Anyone think it’s a bad resistor pack?

Also tested power to injectors and have power to all of them

 

[Jacob_Barnes520GST]

Just swapped back to old tb for the hell of it and same symptoms. I’m stumped.

 

[pauleyman]

Heres an interesting one, I replaced my throttle body today with new gaskets, and all of a sudden I have no fuel in 3 and 4. I pulled the plugs and 1 and 2 were wet but 3 and 4 were dry. Can anyone give me an idea why the injectors aren’t pulsing? The car will try to start after the first few cranks but then won’t do anything

How do you know 3 and 4 arent firing correctly but 1 and 4 dont just have spark issues.

 

[Jacob_Barnes520GST]

I checked spark across all 4, and they all had spark. My 1 and 2 plugs were wet with fuel but 3 and 4 were bone dry

 

[pauleyman]

At least get a noid light and see what is firing.

 

[Jacob_Barnes520GST]

That's the plan, I'm bringing one home from work today. I'm suspecting its the resistor pack. If that's it, then my CAS must have just magically gone bad after I drove it into the driveway

 

[1990TSIAWDTALON]

If they were wet, they were getting fuel but not burning it. Maybe I'm crazy but what it sounds like.
Firing order correct?
PTU plugged in good?

 

[Jacob_Barnes520GST]

I checked the firing order and the ptu is plugged in well. That was my first suspicion. I will check the ptu again. Seems logical because that is in the general vicinity of the TB. I will try to check again when I get home and keep this updated

 

[luv2rallye]

Also tested power to injectors and have power to all of them

+12V always goes to one side of each with ignition on. The other side gets a ground pulse by the ECU (based on CAS output timing) to fire each injector.

 

[Jacob_Barnes520GST]

Thank you, I have a noid light that I will be using tonight to see what all is firing. I will keep this thread updated

 

[Jacob_Barnes520GST]

Just tested injectors with a noid light. No pulse on 3 and 4 but have power. 1 and 2 working just fine

 

[Jacob_Barnes520GST]

Also verified ecu is working as well

 

[Jacob_Barnes520GST]

Any help is really appreciated. Need to get this car back on the road

 

[delta448]

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[Jacob_Barnes520GST]

I thought it was the resistor box too, but I replaced it with a known good resistor and same symptoms

 

[Tyeler18]

The resistor pack supplies 12v to the injectors, since you have 12v we can assume the resistor pack is fine. How did you test the ecu? Since you don't have injector pulse on 3/4 but do have power that means something between the injector and ecu is not supplying a ground. You need to check for ground pulse at the ECU on 3 and 4.