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-   -   Check engine light on-cant get codes -RICH etc (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/check-engine-light-cant-get-codes-rich-etc-951324/)

MIKE-P-28 04-22-11 05:53 PM

Check engine light on-cant get codes -RICH etc
 
Hello guys, its been awhile. Pretty well versed in the ways of the rotary 7 :) well first gen that is but anyway:

Heres what i got, picked up a very nice 90 vert. 90,000 orginal miles for cheap. $2700 to be exact. Check engine light on/jump ground the single green by battery and it stays on / no blinky blinky. Heres what i have and what i know.

Car ran fine according to orginal 1 owner guy except occassionally it would stall when returning to idle. He took it to a 'mechanic' this guy replaced the tps. I found the ecu was freaking soaked. Took it out and dried it out (pretty versed in electronic repair) and it will now start but is RICH as hell! Little lope at idle and extremely touchy on throttle. Barely pressed the throttle and she will hit 4k.

What i have done is so far is ecu cleanup, regrounding of ecu etc grounds, going to check tps when i get home but is the tps that damn sensitive. I thought the computer mainly used o2 , maf and air flow meter at idle. Any thoughts on why the computer wont throw codes? Think ecu got a little short circuit? There wasnt any rust or corrosion of the components inside. Thanks and any thoughts? By the way using my rotary engine compression checker it showed about 115,118,122 front rotor, rear 115,119,124 rear.

lastphaseofthis 04-22-11 06:15 PM

If you look in the FSM in the fuel and emissions section page 71, you can ground pin 1I which is the same as grounding the plug at the battery, in case there is an open between the two.

You can also take a multimeter to each of these inputs to find bad sensors, you can also use the output voltages, although less useful. page 78-80 is our best friend. or the whole FSM for that fact.

MIKE-P-28 04-22-11 07:49 PM

Ok the wire is good all the way to the ecu. Open the case of the ecu connection good from test at battery to inside the ECU. Let me ask a question, when the key is turned on with all the lights lit up is there a ticking sound from around the upper intake manifold? It really sounds like an injector clicking on and off... its like around 2x a second sound of click, that would explain it if the ecu is always pulsing that injector

MIKE-P-28 04-23-11 11:24 PM

ECU had a bad IC in it, causing the front primary injector to pulse regardless of running condition. Replaced the IC and runs pretty damn good.


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