# fuel injectors



## grad (Dec 30, 2013)

Hi. 
I own a 1994 Nissan Sentra who has had a long and busy life. With close to 2500 miles the engine has reached the end of it's useful life but the rest of the car still has a few miles left to run. I do most of my own work and once again need help with the latest problem.

I found an an almost identical engine with less than 100,000 miles in a wrecking yard to replace the old one. Fairly straight forward swap but I can't get the engine to start. All the plugs are connected and appear to be tight. I have good spark, timing seems on, but only runs if I manually inject gas in the intake manifold. There is +12 volts at each injector but the injectors don't get a pulse signal. The only code in the ECM is 55 which the manual indicates might be normal. 

The old engine was still running when I swapped it out. The "new" engine was running when it run off the road. All plugs are connected so I expect it should run but it don't. Have not found anyone familiar with this problem.


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## otto888man (Dec 30, 2013)

Does this engine uses a distributor? or not? Did you use the old ECM? Does the engine uses crankshaft & camshaft position sensor?


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## rogoman (Dec 16, 2004)

There's a good chance that the camshaft position sensor, which is built into the distributor, is bad or the harness connector is not plugged in. Install the old distributor which apparently was working to see if it fixes your problem.


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## grad (Dec 30, 2013)

It has a crank angle sensor behind (under) the distributor. Timing light shows that the timing is on, the distributor has not moved.


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## grad (Dec 30, 2013)

I don't understand how / why the engine runs when I squirt gas in the intake if there's a problem with the distributor or local wiring.


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## otto888man (Dec 30, 2013)

You are basically replacing the fuel that the injectors should have squirted. The crank angle sensor could be responsible for the fuel trim but the ECM does not see it then it will not inject any fuel. Does the new engine comes with a distributor , crank & cam sensor?


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## otto888man (Dec 30, 2013)

The timing light indicates the pulse from the distributor, not from the crank sensor.


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## grad (Dec 30, 2013)

the engine was complete, even came with transaxle. All the harness on the engine up to where it was off near firewall.


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## otto888man (Dec 30, 2013)

Swap the crank sensor from the old engine see if the engine starts. If it does not remove the distributor. Then swap it. Before swapping it be sure you mark the relationship with the head & the distributor so you do not loose the timing of the engine.


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