Injectors aren't firing

[johnnymac09]

Hello, I just finished swapping my 2.9 with another 2.9 I had. I replaced all the gaskets, seals, sensors, timing chain, water pump, fuel injectors and clutch. The engine cranks over fine, has spark and fuel to the rail. If I spray starting fluid into the intake the engine will pop and die otherwise it just cranks over with no combustion. I am pretty sure that the injectors are not firing, but I am borrowing a tester from a mechanic friend tonight to be sure.

My question is, if the injectors aren't firing, what do I do next? Relays? Fuses? ECM? Distributor?

The engine was out of an 88, but I don't think it was original to that truck, and my truck is an 89. Thank you in advance.

 

[Psychopete]

If they are working, it should be flooding out really bad.

Have you pulled a plug to smell and inspect it for raw fuel?

How much accelerant are you putting into the upper intake plenum?

Pete

 

[85b2chopper]

maybe check to make sure the timing chain is in the correct position?

 

[koolmilds]

make sure the injector harness is plugged in ? something i found on my replacement 2.9 was someone installed the injector harness backwards. (injector plug #6 was on #1 injector.)

 

[johnnymac09]

Thanks for the suggestions,

I have pulled a plug and it is dry as a bone. I am just putting a small 2 second spray of starting fluid in. Just enough to know that it fires, I don't want to damage the engine.

Currently I am ruling out timing chain as it doesn't seem to be getting fuel to the cylinders. But is there a way to check without taking the front of the engine apart again.

I have checked all the connections on the harness, in fact last night I put my old harness on the new engine, being very careful to label each wire.

Like I said I am 99% sure that the injectors are not working, and I am going to test them tonight to be sure, but I am looking for suggestions on how to fix them.

 

[koolmilds]

reset the inertia switch ?

 

[mudnsnow]

first look if you have fuel pressure on the rail. After this you should check if you a "+" on one of the 2 wire on each injector when key is on. On the other wire at the injector you should have a "-" pulse when you crank the engine. A tester is very easy to make, you only need 2 wire a LED and a resistor, but i don't remember the value of the resistance .

 

[mudnsnow]

http://www.electronics-tutorials.com/test-equip/led-test-lamp.htm

here the link
a 560 ohms resistor is needed

 

[johnnymac09]

Ok,

I check the fuel inertia switch last night and I push the button to be sure even though it wasn't tripped.

I have fuel pressure on the rail. I just tested the #1 injector with a light and nothing happened, no light.

What now?

 

[mudnsnow]

have you power at the wire? have you pulse?(you can't see the pulse with a normal test lamp)......

 

[johnnymac09]

Using an injector test light, with the proper resistance, I did not see a pulse when turn the engine over.

Using a normal test light connected to ground, I found power on both terminals of the connector. Does this mean there is a short somewhere? Could it be a problem with the ECM?

 

[bobbywalter]

sounds like the ecm isnt grounded right.


make sure the smaller black wires have good ground. though generally the pump wont cycle in that case, but it could be modified from that.


what codes does it give you??

 

[johnnymac09]

The smaller black wires? Are these in the wire harness to the ECM? How would I test that they have a good ground?

Unfortunately I don't have a code reader for this truck.

 

[koolmilds]

The smaller black wires? Are these in the wire harness to the ECM? How would I test that they have a good ground?

Unfortunately I don't have a code reader for this truck.

dont need a code reader, just a piece of wire and a functioning MIL on the dash.

 

[johnnymac09]

dont need a code reader, just a piece of wire and a functioning MIL on the dash.

Where do I put the wire? What is a MIL?