Posted December 16, 20195 yr comment_589348 Hey Team I have spent a lot of time on this forum and i want to say thank you all so much this is an incredible community. I have hit a brick wall and looking for a little help. Background story; I'm helping a friend of mine fix his 280z with 30,000 miles on it all original. Car has been garage kept all its life. Really really well taken care of. Apparently some one A-hole mechanic tried before me and failed miserably and i don't know what he/she messed up or touched. After them the car didn't even start. Fixed that issue. (FACE PALM) ?♂️ When you try to start the car it tries to start but never does on its own. If you give it gas than the car starts but it is runs rough(motor shaking). Have to keep the gas paddle pressed in just a little to keep it running. Car smokes white/bluish smoke from the tail pipes. (running rich) ( Gas smell). Changed the oil after the previous Mech worked on it smelled like gas was in it. Did a double flush much better now. Things i did and tested on the entire car: Spark Plugs - New Spark Plugs Wires - New Battery - New Battery Terminals - Cleaned Distributor cap - Cleaned and polished Dizzy - Cleaned and polished Pick Up - Adjusted to correct distance from roller according to 0.08in or 0.2mm Distributor Vacuum - Good Ignition Coil - NEW (built in resisters original ceremic resistor was missing) (https://www.holley.com/products/ignition/ignition_coils/street/super_stock/parts/8140C) Fuel Pressure - 22-25psi in when engine is off, while the car is running at low rpm 30psi+ ( 700 to 1k) Smoke test - No leaks AFM - Refurbished still sealed was installed last month AFT Idel screw - Did not mess with Throttle Body Screw - NO EFFECT when turning clock or counter clock Electrical - 12V all over from Body, Engine, - All good Ground Connectors - Clean Coolant Temp Sensor - Ordered Arriving tomorrow (CANT IMAGINE ITS THE REASON) Timing - Seems good 10 degrees of from original zero marking Cylinders Compression Test - 125 + on all Cylinders Injectors connections - look good Injectors - listen to them with stethoscope sound health strong tick HELP!!!? Thank you again for reading. I will be testing tomorrow. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/ Share on other sites More sharing options...
December 16, 20195 yr comment_589350 43 minutes ago, Cyrillink said: When you try to start the car it tries to start but never does on its own. If you give it gas than the car starts but it is runs rough(motor shaking). Have to keep the gas paddle pressed in just a little to keep it running. Car smokes white/bluish smoke from the tail pipes. (running rich) ( Gas smell). Coolant Temp Sensor - Ordered Arriving tomorrow (CANT IMAGINE ITS THE REASON) The coolant temperature sensor is the most likely cause, based on your symptoms. You need to measure the resistance at Pin 13 of the ECU connector to ground to know for sure. Installing a new one won't help if the wires aren't connected to the ECU. I just now realized, after many years of browsing through FSM's and Fuel Injection Guides, that this drawing has the pins numbered, right in the drawing. I never looked closely enough before. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589350 Share on other sites More sharing options...
December 16, 20195 yr Author comment_589354 Installing a new one won't help if the wires aren't connected to the ECU. - Zed Head _________________________________________________________________________ Thank you for confirming my suspitions. What do you mean if the wires are not connected to the ECU.? Do you believe that cables broke, just dirty inside or disconnected? Should I not even take out the coolant temperature sensor and clean it or even bother replacing it even i have it? Sorry for the weird question. Edited December 16, 20195 yr by Cyrillink didnot add the quote Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589354 Share on other sites More sharing options...
December 16, 20195 yr Author comment_589356 5 minutes ago, Cyrillink said: 2 hours ago, Zed Head said: The coolant temperature sensor is the most likely cause, based on your symptoms. You need to measure the resistance at Pin 13 of the ECU connector to ground to know for sure. Installing a new one won't help if the wires aren't connected to the ECU. I just now realized, after many years of browsing through FSM's and Fuel Injection Guides, that this drawing has the pins numbered, right in the drawing. I never looked closely enough before. Installing a new one won't help if the wires aren't connected to the ECU. - reply thank you for confirming my suspitions. What do you mean if the wires are not connected to the ECU.? Do you believe that cables broke, just dirty inside or disconnected? Should I not even take out the coolant temperature sensor and clean it or even bother replacing it even i have it? Sorry for the weird question. And thank you for attaching the exact connections with pins Edited December 16, 20195 yr by Cyrillink Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589356 Share on other sites More sharing options...
December 16, 20195 yr comment_589359 The only way to be sure that that the wires are intact from the coolant temperature sensor to the ECU is to measure resistance at the ECU plug. If you do that you are testing the wires, the sensor, and every connection along the way. I would not do anything to the coolant sensor, not even remove the plug at the sensor, until I measured resistance at the ECU plug. Start at the the end, not the middle. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589359 Share on other sites More sharing options...
December 16, 20195 yr comment_589372 have you pulled the plugs to confirm the rich running? Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589372 Share on other sites More sharing options...
December 16, 20195 yr Author comment_589390 9 hours ago, Zed Head said: The only way to be sure that that the wires are intact from the coolant temperature sensor to the ECU is to measure resistance at the ECU plug. If you do that you are testing the wires, the sensor, and every connection along the way. I would not do anything to the coolant sensor, not even remove the plug at the sensor, until I measured resistance at the ECU plug. Start at the the end, not the middle. Hey Zed, Tested the resistance and i was able to get a reading back, the reading was similar to when the sensor was pulled out of the car for cleaning. Took out the plugs cleaned them to make sure everything is well. Car did the same thing. Blue smoke, rough idle while only holding the paddle down. Going to do another smoke test just to triple check. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589390 Share on other sites More sharing options...
December 16, 20195 yr Author comment_589391 3 hours ago, Dave WM said: have you pulled the plugs to confirm the rich running? Yes, plugs had moisture on them. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589391 Share on other sites More sharing options...
December 16, 20195 yr comment_589392 2 minutes ago, Cyrillink said: Hey Zed, Tested the resistance and i was able to get a reading back, the reading was similar to when the sensor was pulled out of the car for cleaning. Without the actual number and knowing where it was taken, can't really tell what you're saying here. It might the the most important measurement you can make on the EFI systems. "a reading back" doesn't read well. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589392 Share on other sites More sharing options...
December 16, 20195 yr Author comment_589394 5 minutes ago, Zed Head said: Without the actual number and knowing where it was taken, can't really tell what you're saying here. It might the the most important measurement you can make on the EFI systems. "a reading back" doesn't read well. I am getting a better snapon Multi meter right now going to test it again and get back to you. Thanks again Edited December 16, 20195 yr by Cyrillink Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589394 Share on other sites More sharing options...
December 16, 20195 yr comment_589395 Not to throw you off the troubleshooting track that's been laid out, but is there a chance that the guy who worked on it before you removed the injector connectors and cross connected them, or in other words, put the wrong connector(s) on the injectors? Sent from my Coolpad 3310A using Tapatalk Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589395 Share on other sites More sharing options...
December 16, 20195 yr Author comment_589397 23 minutes ago, Zed Head said: Without the actual number and knowing where it was taken, can't really tell what you're saying here. It might the the most important measurement you can make on the EFI systems. "a reading back" doesn't read well. car is indoors with the heat on to 60f sensor reading from the ECU Harness 2.07k Ohm. Link to comment https://www.classiczcars.com/forums/topic/63285-280z-78-wont-idle-running-rich-out-of-ideas/#findComment-589397 Share on other sites More sharing options...
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