84 corvette cranks no start help. Temp sensor part number?
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Joined: Apr 2020
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From: Philadelphia
84 corvette cranks no start help. Temp sensor part number?
Hey guys replaced my fuel pump last summer car ran great. This year I had it on started right up. Noticed one day it would crank but wouldn’t start. I hear my fuel pump so it’s job. But again no start. I have new injectors new ignition module from 2 years ago.
I read the front temp sensor on these engines when they go bad they tell the ecm to not start. I have a 2 wire sensor I think it may be original. I heard there’s 2 new sensors out? Can I get a good part number someone who has swapped one? Thanks I’ll try sensor first plus needs to be replaced anyway.
I read the front temp sensor on these engines when they go bad they tell the ecm to not start. I have a 2 wire sensor I think it may be original. I heard there’s 2 new sensors out? Can I get a good part number someone who has swapped one? Thanks I’ll try sensor first plus needs to be replaced anyway.
Pro
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From: Liliha Bakery stuffing my face with coco puffs!
I think you're barking up the wrong tree but since we are here... That sensor can tell the ECM "it's freezing" and will need a richer start up fuel and on the other hand if it fails on the other spectrum "it's fricking hot," then the ECM will in turn provide little to no enrichment. Break out your DVM and take ohms reading per this chart.
This is just a short list...
Have you verified that you have spark?
Take the lid off and have an assistant crank, can you see fuel being injected out of the injectors?
A failed TPS +2.5v can cause the injectors not to fire.
You need to do some troubleshooting.
This is just a short list...
Have you verified that you have spark?
Take the lid off and have an assistant crank, can you see fuel being injected out of the injectors?
A failed TPS +2.5v can cause the injectors not to fire.
You need to do some troubleshooting.
Thread Starter
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Joined: Apr 2020
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From: Philadelphia
Should I send this to general discussion? Not tech?
also ohms I am getting off the sensor as it’s plugged in is OL. So I’m assuming it’s shot since it’s OL.
anyone have good part number?
also ohms I am getting off the sensor as it’s plugged in is OL. So I’m assuming it’s shot since it’s OL.
anyone have good part number?
Melting Slicks
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Here's what you need to update that sensor. Coolant Temperature Sensor with Connector for Chevy GMC Olds Buick Isuzu Pontiac | eBay
Pro
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From: Liliha Bakery stuffing my face with coco puffs!
As long as it specs out to the chart, I don't see why not. Assuming the connector is different then the original '84 and the reason it ships with accompanying pigtail? Just make sure you get one that the probe that screws into is all metal. I had one on a different type vehicle that the probe was plastic. Hooked up my scanner and it would never go over 180dF but started puking coolant!!! Removed the old defective one and the plastic probe was full of holes!!!
Drifting
Joined: Nov 2004
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From: Indiana
2024 C3 of the Year Finalist- Unmodified
I had a couple of no-start experiences with an 84. The car would start when cold but when warmed up it would not start. Found that it was because engine was warm but low on coolant it would not start. Fixed leaky water pump and kept coolant filled and all was ok. During this exercise I think I read that if the oil pressure sensor was bad it would also be a no-start condition with the computer thinking that no oil pressure would damage engine if started.
Gary
Gary
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Michael S. Palmer
Team Owner
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From: Park City Utah
I had a couple of no-start experiences with an 84. The car would start when cold but when warmed up it would not start. Found that it was because engine was warm but low on coolant it would not start. Fixed leaky water pump and kept coolant filled and all was ok. During this exercise I think I read that if the oil pressure sensor was bad it would also be a no-start condition with the computer thinking that no oil pressure would damage engine if started.
Gary
Gary
First, there is no coolant level sensor in the '84, or any programing in the ECM or safety circuitry that will stop or prevent running if it's low on coolant.
Second, the oil pressure switch is a back up/redundant circuit that does power the fuel pump. But since it is a back up, it's not intended as a oil pressure safety. The PRIMARY fuel pump circuit is a fuel pump relay that is energized by the ECM and sends power to the fuel pump. If some part of that fails (the relay, etc) then when cranking the engine, once oil pressure is built, the fuel pump will run and the car will start.
The car not starting when warm...and low on coolant was coincidence and you never found the actual problem.
