im working on a 85 chevy s10 blazer which had a 89 4.3L installed. the guage is reading extremely hot most of the time but its actually not so i think its the sensor i know they go bad but i dont know if the right one is even in there. the engine temp sensor in the block is a single wire temp sensor style so im not sure if the 85 sensor was used in the 89 4.3l block because thats the way the wiring is setup. does the 89 4.3l temp sensor have the double wire plug and the one that is in there def the 85 and can that 85 even be used in the 89 block to read right?

 

according to advanced auto parts the i used the 89 4.3l i see BWD models WT3002P , WT413, and WT3002 that have a single electrical connection. but even though that sensor is for that block and has a single connection does it have different resistance or whatever where it wouldnt work with the 85 computer? or would have the computer been changed also since its now an 89 4.3L?

then for the 85 with a 2.8L i get BWD model WT359P, WT359, and WT 760.

or is there something else im missing

 

85 was factory carbed so if you have a 89tbi they most likely running a 89 ecm. On tbi engines there is 2 temp senders/sensors, one for the ecm, one for the gauges. Most tbis the if I remember right the one in the head is for the gauge and the one in the intake is for the ecm. 4.3s really aint my thing (I hate the shaking things) so somebody that knows them better will have to comfirm/correct this. If its got the factory gauges I'd look at a sender for an astro van with a 4.3 from 85. That way if gm did change the senders that one might be correct for your 85 dash gauge. Then again it might not work, I really don't know.

If its a 89 4.3 but running a carb (like I figure it is) look at the astro suggestion above.

Honestly without knowing a bit about the fuel delivery or how the swap was done I'm reaching. We need some more info on the swap first.

 

ok ill get that info tomorrow

 

its fuel injected

 

sorry again my friend told me it was fuel injected but its not i went to look at it myself today . so they made 89s with carbs? or do you think its the block and heads with with an 85 intake and carb?.

as far as the temp sensors go . in the middle of the block on the passenger side it has the single wire sensor or sender. on the front of the intake right next to left of the thermostat housing there is a sensor but not sure what it is . obviously coolant doesnt touch it but i dont know it ifs a temp sensor. its a 2 wire harness in the oval shape. i was dressed to nice to lean into the truck and explore more to see if here is another sensor somewhere. i dont know much about these chevys.

 

The s-series didn't get 4.3s till 88 as a factory option, fuel injection was standard on them by 86.

4.3s were around since 79 if I recall and there was factory carbed models. Also aftermerket carb intakes.

There was factory electronic carbs that had a very simple ecm for emmisions stuff. Sounds to me you have one of these intakes. There is a coolant crossover in the front of 4.3s so I bet that was a temp sender. I'm willing to step out on a limb and bet the one in the head is for the gauges. Only problem being an engine swap it could be wired up however the guy doing it felt like that day.

 

The 89 is TBI unit. there are 2 injecters that sit on top of the TBI that inject fuel directly into the TBI . The two wire sending unit at the front of the intake manifolds is temp. sensor for the ECM. The single wire sensor in the head is for the dash gage/light.

 

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you can see on the intake a different sensor related to the oval harness which might be spliced in some where and not factory. .im going to be bringing it to my place probably on tuesday so i can have a closer look at it .