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no injector pulse?

T

tweeder

New member
All I did was disconnect the battery and took off plug wires to remove the tunkside exhaust to weld up a leaking header and weld a wideband bung in the down pipe. I also replaced the map sensor. With a new one. It cranks and I have fuel pressure. I also checked and verified spark on two random wires. I also noticed that while cranking the temp guage peggs which it never has before. I have fuel pressure but no wet fuel on plugs. I hooked up hptuners and scanned as I cranked it over and nothing reading on the injector duty or either injb1 or injb2. Looks like the injectors ain't firing.

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You won't pulse when cranking. You only pulse before cranking when the pump primes. Then once it starts injectors resume.
 
Monday said:
You won't pulse when cranking. You only pulse before cranking when the pump primes. Then once it starts injectors resume.
Click to expand...

Ok wrong choice of words then, basically I'm getting no fuel from the injectors. I have power to both injector wires.
 


Yeah.. I thought you meant not injector pulsing to give you fuel. The way it works is the pcm on key on, primes the fuel pump and pulse the injectors quick to prime the cylinder for start up. Injectors are then not pulsed again until start up or a little throttle.

The ignition supplies voltage to the injectors and they stay hot as long as the ignition is on. The pcm grounds the injector as it sees fit.
 
BillBoost37 said:
Yeah.. I thought you meant not injector pulsing to give you fuel. The way it works is the pcm on key on, primes the fuel pump and pulse the injectors quick to prime the cylinder for start up. Injectors are then not pulsed again until start up or a little throttle.

The ignition supplies voltage to the injectors and they stay hot as long as the ignition is on. The pcm grounds the injector as it sees fit.
Click to expand...


Yeah my injectors ain't giving me fuel. I will have to re check but I think there was voltage to both wires even while cranking.
 
Welli found the problem, it's the new map sensor, I unplugged the new one and plugged it into the old one but left the vacuum line connected to the new one. It took a few cranks but it fired up. I left it running and plugged it back into the new sensor and it stayed the same. If I shut it off and restart it in the new, it won't start. This is the sensor I bought.
http://www.ebay.com/itm/231...id=p3984.m1439.l2649

Andy suggestions as to why the new one don't work?
 
hook up a vacuum pump to the map and watch what it does on a scanner, probly a bum sensor.

On standard's website they list the as4 for vin 1,

ship it back on warranty?
 


Seachicken said:
hook up a vacuum pump to the map and watch what it does on a scanner, probly a bum sensor.

On standard's website they list the as4 for vin 1,

ship it back on warranty?
Click to expand...

I'm not sure if I'm a vin 1 as I have a donor motor in the fiero. For the vacuum thingy, does the vehicle have to be running or just KOEO? I've contacted the seller, waiting a response. I have put in a 2 bar that I had ordered for another project but though it was wrong as the idle was surging, turns out I didn't let it learn. Now that same sensor idles fine. What should the map numbers be with the engine running?
 


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