serious acceleration problem
serious acceleration problem
I have a 91 sentre 1.6 sohcga xe model. vehicle will idle fine but when idle is increased to about 1500 rpm engine will surge up and down like it has a rev limiter and it will keep surging even if you open the throttle all the way it will stiil surge until you bring it back down to a idle. first i tryed a mass air flow sensor. i checked all the grounds for the computer and at the battery. i have tryed a ecu and a distributer because with a noid light on the injector i am loosing injector pulse when engine starts to surge. computer will not store any codes but i can tell vehicle is running very rich of course. i have tryed disconnecting the exhaust to make sure there is no restiction and egr valve is not sticking i even disconnected it to make sure. every sensor has been disconnected or tapped on or inspected. does any have any ideas????????? i guess something could possibly be wrong with the wiring. does anyone know i'f the eccs relay beside the computer could be causing this surge????????
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Und3rprshUr
- Posts: 570
- Joined: Sat Oct 19, 2002 5:53 am
- Car: My 300Z
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Und3rprshUr
- Posts: 570
- Joined: Sat Oct 19, 2002 5:53 am
- Car: My 300Z
three top things that give input to ecm to contol injector pulse is first on list is airflow meter second would be cam sensor. third would be o2 but an o2 gross failure would not cause the problem. try this disconnect the air flow meter while its running it should idle still but try and rev it up you should get very similar results to what you had when it starts stumbling. the cam sensor is in your distributor and may be oil contaminated to check this pull your cap off and check for signs of oil. i have read you post a few times and it seems there is something missing..like a peice of info that may help ..is there anything else goin on with the car or before this happened did anything significant happen but was just ignored?
THE BATTERY VOLTAGE IS FINE AND ALTERNATOR IS CHARGING 14.5 VOLTS WHILE SURGING. BOTH THE MASS AIR FLOW SENSOR AND DISTRIBUTER HAVE BEEN REPLACED AND SO HAS THE ECM. AS I SAID BEFORE EVERY SENSOR HAS BEEN DISCONNECTED OR TAPPED ON WHILE ENGINE IS SURGING. YOU KNOW GROUNDS ARE VERY IMPORTANT WHEN YOU TALK ABOUT THE ECM BUT I HAVE RE-GROUNDED ALL OF THEM. HELPPPPPPPPPPPPPPPP
at you air flow meter at the ground wire splice in another wire and bolt it to the engine somewhere as a extra ground. to test if this theory will work. back probe the ground wire on the air flow meter and connect a wire to it and run it to ground and rev the engine to the cut point your experiancing. this was at one time a very common problem on the early 90's sentras
WELL I DID NOT FIND A GROUND PROBLEM AT THE MASS AIR FLOW SENSOR BUT I FOUND A BROKEN WIRE AND GUESS WHAT? IT WAS THE PROBLEM THE WHOLE TIME. THE WIRE WAS BROKE WHERE IT BENDS AROUND AND PLUGS INTO THE SENSOR. THAT CAR HAD BEEN TO 3 SHOPS BEFORE I BOUGHT IT. THANKS FOR HELPING ME FIGURE IT OUT (NISTECH)!!!!!!!!!!!!!