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1.8 injector help

Hi im trying to bring a 74 914 with a 1.8L back to life. It dident have spark so i replaced the points. now i have spark...but the problem is that my injectors dont fire. If i unplug an injector and test the terminals i have power at both terminals key on engine off is this normal or does it sound like a short to voltage? If so can any tell me a simple path that the injector wires travel? Also do any of the inputs from the sensors affect injector pulse on start up? if so could that be a problem? Any help would be greatly appriciated Thanks in advance!!!
Old 09-07-2010, 08:24 PM
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Hi Bronto914, the dual relay connections are very important, the voltage on both injector pins when key on is normal, the points breaking is what sends the signal to the ecu to fire (ground) one side of the injector connector. The cable to the single connection cable from the ecu will attach on the (-) negative side of the coil as will the points wire and the black/purple wire from your tach. Hope this helps. Where are you located??
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'74 914-1.8
Old 09-08-2010, 10:09 AM
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does the ecu take readings from any sensors to control injector pulse during start up or does it just send a ground to the injector every time the points break? sorry if any of these questions seem novice i am new to any porsche injection system.
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Old 09-08-2010, 10:35 AM
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I believe the point do most of the work but there are sensors such as cyl head sensor, and there is a large one that I think is called a timecert? (mounts on top of the motor under the air manifold) that modify the amount of fuel to add depending on the engine temp and such
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Old 09-08-2010, 10:41 AM
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alright i bought the car becasue the body is mint and i got it for dirt cheap the problem i found out is that a few wires are burnt that run underneath the pasenger side intake manifold tubes. thats why i was asking if a bad connection from one of the wires will cause the injectors not to pulse when i get home tonight i will check the single black wire from the ecu to the coil and make sure its on the negative side of the coil and that, that wire isent harmed in any way. I wanted to wait to replace wires untill i found out for sure what it will take to get the injector pulse back
Old 09-08-2010, 10:51 AM
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so there should be a wire runing from the points inside the cap to the negative terminal on the coil correct?
Old 09-08-2010, 10:53 AM
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so from what i understand there should be a black wire from the ecu to the negative terminal on the coil? Where is this wire on the ecu is it supposed to be in the harness? I uncoverd the wires in my harness from the ecu conector and every one of them is white. On my coil i have a green and a black w/purple wire on the negative side and two wires on one spade connector on the positive side. Am i missing a wire?
Old 09-08-2010, 07:38 PM
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The FI wires are all white. If one of the two on the (+) side of the coil is white, or tan (oil-stained white), try moving it to the (-) side of the coil.

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Old 09-08-2010, 09:31 PM
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Big thanks to dave the white wire was on the negitive side i switched it and now she starts, so thank you very much. it has a very high idle tho besides a vacume leak is there any other comon reasons for a high idle
Old 09-10-2010, 05:41 PM
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Usually vacuum leaks in a 1.8 result in a very poor lumpy idle or the car being unwilling to idle.

A cold engine will often idle somewhat high, and that should drop to normal as the engine warms up. An abnormally high idle could be caused by air leaking through the Aux Air Reg or the Decel Valve. Or from overly-advanced ignition timing.

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Old 09-11-2010, 08:42 PM
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does the decel valve look like the fuel pressure regulator? The fuel pressure regulater is in line after the injectors on the driver side and then runs back to the tank, But on the passenger side there is a valve that looks identical to the regulator but is ran with all the vacumme lines that the decel valve uses? if it would be helpful ill post a picture to give a better understanding.
Old 09-13-2010, 08:11 AM
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One version of the decel valve looks similar to the fuel pressure regulator. I don't have a picture handy, but I think there is one in Haynes.

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Old 09-13-2010, 09:30 PM
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