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injectors?

ok i got it in the shop.. the guy is checking it out... the DME is ok.. it will run if you un plug one of the injectors (doesnt matter which one) if you connect an ohm meter to it it is getting a pulse and at the right strength... what could cause this?

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Old 11-20-2003, 02:29 PM
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The fuel pressure regulator sounds right..... but you can also get problems like this when one of the injectors is not up to snuff. It can even mask itself as you describe.
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Old 11-20-2003, 02:39 PM
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Doesn't sound like your "shop" knows what they are doing.

Good luck!
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Old 11-20-2003, 03:15 PM
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it has a new regulator
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Old 11-20-2003, 04:04 PM
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i have... pressure is in the correct range
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Old 11-20-2003, 04:13 PM
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could it be a ground to the injectors? if so which one grounds the injectors?
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Old 11-20-2003, 04:17 PM
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If you want to check the injector wiring ... here is a test sequence I had saved........ I can't remember where I got it.... but it should help you out.

1. Unplug all the injector connectors carefully. You can do this by prying off one side of the square C-shaped spring-clip with a screwdriver. Then grab the plastic connector and wiggle it side to side as you pull it off (do not pull on the wires!).

2. Turn the ignition-key to ON, but car not running.

3. Test the rearward pin on the connector for positive. It should be a constant +12v on all of them relative to a chassis ground.

4. Test the forward ground pin on the connector for positive, none of them should register any voltage. If you have some voltage, you've got a short somewhere. It may be in that connector you have in your hand, or a different one.

5. Test the forward ground pin for continuity with chassis ground. They should all be open because it's the DME that grounds the injectors on & off to fire them.

6. Test the forward ground pin for continuity between injectors 1 & 2, then 3 & 4. These should be connected with zero resistance. There should not be any continuity between injectors 1&3 or 1&4 or 2&3 or 2&4.

7. Turn off the key and test for continuity between each connectors postive & ground pins. Wiggle the wiring underneath the rubber shield and there should be no continuity. If there is the two sides are are shorted. Since all the injectors are eventually connected together, any short in one of the connectors will give sporadic or complete failures in all of them.
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Old 11-20-2003, 04:21 PM
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GREAT!!! thanks!!
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Old 11-20-2003, 04:24 PM
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The "will run when one of the injectors is disconnected" means fuel pressure problems.

If any one of the injectors is disconnected and the car runs it's fuel pressure problems.

To check the injector pulse get a noid light.

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Hugh - So Cal 83 944 Driver Person
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When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
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Old 11-20-2003, 08:08 PM
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