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

Engine hard start, fuel out of exhaust

Old Apr 4, 2008 | 05:10 AM
  #26  
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You could send your injectors out to be cleaned and flow tested for about $16 a piece.

Brian
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Old Apr 4, 2008 | 09:27 AM
  #27  
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To check the TPS you need an Ohm meter. Unplug the Throttle position sensor and check resistance at idle & full throttle. The TPS is on the front of the throttle body... a little black box with a plunger on it that goes in & out when you mash the gas or rotate the throttle plates. You are checking this black box with the plunger that rides on a cam on the throttle plates. You want to test the resistance between the horizontal pin and the right vertical pin. Resistance should be 1000 ohms with the throttle closed & 4000-6000 ohms at wide open throttle. This according to my BRAND NEW Haynes manual.... You should buy one immediately.

Ramses666
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Old Apr 4, 2008 | 12:29 PM
  #28  
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HAILERS
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Originally Posted by EnBom_Rx-7
No, I can sit there and crank it, but unless I am on the gas it will not start. It won't fire up without the gas pedal being down.

UNLESS IT IS WARM, then there is no problem. This is for cold starts only. Just bought a compression tester and about to check compression.
************************************************** ************************************************** ******************************

The water thermo sensor on the back of the water pump housing could cause your problem with cold starts. If the connector is off the sensor OR one of the two pins inside the plug is pushed back not making contact, that could cause a COLD start problem. Once the engine is warm, the above won't cause a no start problem because the ECU defaults the sensors output to 189* (hot engine).

The ECU uses the rpms under 500 signal, the Start signal from the key to being held to ON, and uses the water thermo sensors output for how much fuel to deliver during START. If the sensor is disconnected as described above, then the ECU sees a HOT engine of 189* and will deliver not enough fuel for STARTING.

The afm has nothing to do with STARTING the engine. Just FYI
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