2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

3800 rpm cut off

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Old Oct 27, 2003 | 09:50 PM
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3800 rpm cut off

My 88 turbo will not rev past 3900 rpm. I cant even ease it past. When I stomp on the gas in neutral it revs to 3900 rpm cuts out drops down to about 1100 and repeats again. The boost pressure stays at vac 20 at idle and equalizes at 0 psi just as the rpm cuts. It sounds almost computer controlled like a rev limiter. I could really use some help here. Thanks
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Old Oct 27, 2003 | 10:13 PM
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Sounds like one (or both) of the secondary injectors is not coming online. Check to see they're both securely plugged in. You'll probably need to remove the UIM.
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Old Oct 28, 2003 | 10:22 AM
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I just checked both sets of injectors are plugged in. any other thoughts
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Old Oct 28, 2003 | 02:39 PM
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Hmmm....Inability to rev above 3800 generally indicates malfunctioning secondary injectors.

What mods are on the car?

Jarrett
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Old Oct 28, 2003 | 03:00 PM
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The car has an aluminum TID, cone filter, RB turbo back exhaust, under drive alt. pulley.
I just sent the injectors to RC and had them cleaned and flow tested. Just bought the car it has never ran right scence Ive had It. Also checked it for codes the other day. it gave me the code for the pressure sensor
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Old Oct 28, 2003 | 03:24 PM
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Pressure sensor wont prevent you from revving past 3800, but get that fixed, pronto!

Now, Here is my next question... What size injectors are your secondaries?
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Old Oct 28, 2003 | 03:26 PM
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the secondaries are the stock 550's
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Old Oct 28, 2003 | 03:29 PM
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Hmmm...Blows that theory out of the water... Unless...

Can you check the resistance of the secondaries?

*just so you know where I am going with this.. If you (or previous owner) mis-matched injector impedance, you may have a blown ECU circut*

Jarrett

Last edited by J-Rat; Oct 28, 2003 at 03:32 PM.
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Old Oct 28, 2003 | 03:54 PM
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just replaced the ecu I had the same thought. I forgot but the engine is a Jspec didnt come with egr and he took off the air pump and acv. do I need to ground any of those connectors?
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Old Oct 28, 2003 | 04:16 PM
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No, those connectors are fine as they sit. Just cover them with tape or something so they dont touch metal.

Now, do you have the resistance of the secondaries?

Jarrett
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Old Oct 28, 2003 | 04:49 PM
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about on each 14 ohms
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Old Oct 28, 2003 | 05:54 PM
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do you have the orifice thingy in the pressure sensor vac line? =/
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Old Oct 28, 2003 | 06:00 PM
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Im not aware of any orfice thingy. its just a hose from the pressure sensor to a split where its spliced in with the BOV
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Old Oct 28, 2003 | 06:02 PM
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spliced into the bov? i dont think its supposed to do that.. mine goes from the pressure sensor to the motor.
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Old Oct 28, 2003 | 06:02 PM
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then again my car doesnt run soooo =/
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Old Oct 28, 2003 | 06:12 PM
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I think from the factory it hooked in to the air control valve. but its been removed
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Old Oct 28, 2003 | 06:52 PM
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14 ohms and its an 88. Thats a good thing. Okay, next check.

Do you have the FSM? Lets verify that the output voltage is present for your secondaries by probing the secondary output directly on the ECU plug.

Chapter 4B of the FSM has the ECU pinout.

Jarrett
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