quick question about what sensor controls injector firing

[dueces]

Hey guys, ive been chasing an issue with my car for a while now, and now that i finally got it back home i can work on it more liberally.

I have spark, verified at the spark plugs. i have flow from the fuel pump. pump runs, and also i disconnected the feed line and jumped the 'T' connector, and plenty of fuel came out. So now i am thinking its narrowed down to the sensor that controls the injectors. I looked and didnt see a crank sensor, so what actually drives the injectors to fire? Cam sensor? If so where would it be located on my 89 efi? im a bit lost and thank everyone in advance for trying to help. thanks

John

[Team Lightning]

If I remember correctly, the sensor that fires the injectors is inside the distributor. 89 autos are different from 90 and up, so maybe someone else can answer also.

[dueces]

Ok thanks. i replaced the disty, and when i did the car was firing slightly, then it just quit again. im lost as to whats really going on....

john

[M3NTAL]

Double check your timing?

[dueces]

I havent done that yet, but with how the car was acting(it started to randomly cut out and randomly not start) i assumed it to be fine considering it would come back online and run great, meaning not down on power like if it were to jump a tooth....

[dueces]

Ok im trying to check timing, but i cant get anything in to rotate the crank(its a dual v pulley). Any suggestions on how to get cyl 1@TDC?

[Damkid]

Pull the dist. cap and crank it over and see if the rotor spins... That's how i'd check for a broken timing belt

But to check the injectors, use a test light on the injectors wires

[georgeb]

You might have to lower the pass side of the motor to get a 21mm socket on the crank bolt.

[dueces]

^^^ thats not what i wanted to hear, lol. Sorry i meant to mention that the timing belt does spin. I stated that the spark plugs had spark, ant the only way for that to happen is for the rotor to turn to make contact but i did in fact watch the rotor turn.

So besides checking timing, does anyone know what drives the injectors, and where it is? Ill have to buy a test light as i dont have one right now.

[scitzz]

You can do the loaner tool thing at auto zone. Ask for noid lights. You plug one into the connector for the injector, and watch for it to flash.

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[scitzz]

Cutting in and out, did you check the VAF connection at the air filter?

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[dueces]

Ok ill look at renting the noid light. Checked the vaf, and connector, and they look fine. anytime ive had issues with vafs the car would always start, but just stumble and die, thats not the issue im having, my car wont even attempt to start.

[crazyrog17]

The fuel injectors are pulsed a ground from the ECU. As long as they're getting constant +12v and their pulsed grounds, you should have fuel in the cylinders.

[Damkid]

^^^ thats not what i wanted to hear, lol. Sorry i meant to mention that the timing belt does spin. I stated that the spark plugs had spark, ant the only way for that to happen is for the rotor to turn to make contact but i did in fact watch the rotor turn.

So besides checking timing, does anyone know what drives the injectors, and where it is? Ill have to buy a test light as i dont have one right now.

Ah ya your right, my bad lol

I always thought the ECU controlled the injectors and it gets its signal from the dist? i could be wrong on that though

you could easily make your own little test light with a small light bulb you got kickin around

[dueces]

The fuel injectors are pulsed a ground from the ECU. As long as they're getting constant +12v and their pulsed grounds, you should have fuel in the cylinders.

I understand that, but the ecu has to see a position sensor to know when to cycle the injectors. IM just trying to find where the sensor is so i can check wiring.

Ill look at doing the light test qhen i get off work. My suspisions are that they arent opening.

Thanks for all the responses so far!