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Oil pressure gauge / 3800SC by TXGOOD
Started on: 07-07-2015 10:11 AM
Replies: 8 (266 views)
Last post by: TXGOOD on 07-09-2015 04:18 AM
TXGOOD
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Report this Post07-07-2015 10:11 AM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
Does anyone know why the oil pressure needle might peg all the way to the right on the gauge on a 3800SC swap?
Thanks
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hnthomps
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Report this Post07-07-2015 11:32 AM Click Here to See the Profile for hnthompsClick Here to Email hnthompsSend a Private Message to hnthompsEdit/Delete MessageReply w/QuoteDirect Link to This Post
Mine read about 80 psi when the vehicle is first started (3800 SC Series II and III).

Nelson
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fieroaddicted
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Report this Post07-07-2015 11:36 AM Click Here to See the Profile for fieroaddictedClick Here to Email fieroaddictedSend a Private Message to fieroaddictedEdit/Delete MessageReply w/QuoteDirect Link to This Post
which sender are you using?
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TXGOOD
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Report this Post07-07-2015 01:11 PM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fieroaddicted:

which sender are you using?


I`m not sure.
The one that is standard on the 3800 engine?
And when I say pegged I mean all the way to the right, way past the upper number.

[This message has been edited by TXGOOD (edited 07-07-2015).]

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fieroaddicted
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Report this Post07-08-2015 05:31 PM Click Here to See the Profile for fieroaddictedClick Here to Email fieroaddictedSend a Private Message to fieroaddictedEdit/Delete MessageReply w/QuoteDirect Link to This Post
did you build your own harness? or have it made? If so, by who? If fieroflyer built it, it is set up for use with an 88 v6 fiero sender. Most likely the sensor on your 3800 engine was meant for a light, not a gauge. However there is one that comes on the 98 3800 sc bonneville. This bonneville had gauges instead of a light so you could use that one as well. I am just finishing up my 3800 sc install and I am going to use the bonneville one. Supposedly it reads better on the stock gauges in the fiero than the 88 fiero one. If ya use the bonneville one, keep in mind it needs to be grounded.

[This message has been edited by fieroaddicted (edited 07-08-2015).]

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TXGOOD
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Report this Post07-08-2015 07:39 PM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
I`m not sure who built the harness and I`m not sure of the sensor.
I know that I give you guys nothing to go on.
I will ask stephen if he knows what kind of sensor it is.
Thanks
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bjc 350
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Report this Post07-08-2015 10:17 PM Click Here to See the Profile for bjc 350Send a Private Message to bjc 350Edit/Delete MessageReply w/QuoteDirect Link to This Post
Mine does the same thing, 88 sensor. I have read that some of the sensors are not actually built for Fiero's but "fit Fiero" and therefore cause the wrong reading. I have not investigated further. It is annoying in an otherwise pretty good car.

edited for spelling

[This message has been edited by bjc 350 (edited 07-09-2015).]

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Darth Fiero
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Report this Post07-09-2015 02:02 AM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
GM made 0-60, 0-80, and 0-120 psi oil pressure sending units that all look the same as the popular 88 Fiero 0-80 psi sending unit. A lot of 90's GM trucks used 0-80psi sending units, some newer ones lacked the internal fuel pump pressure switch the 88 Fiero sender had so these will have a different part number (than the 88 Fiero sending unit). But you can still use one of the 0-80 psi truck sending units if you want. It just won't have the switch for the fuel pump circuit - which you don't need.

GM only used the oil pressure switch to power the fuel pump circuit as a back-up in case the fuel pump relay failed. Fuel pump relay failures used to be fairly common back in the 80's when GM wasn't yet using weather sealed relays for the fuel pump circuit. But with the advent and widespread use of weather sealed relays, failures became much less common so GM eventually dropped running the fuel pump power circuit thru the oil pressure switch altogether (which happened in the 90's).

I am not a fan of using the Bonneville 0-120 psi sending unit in a Fiero with the Fiero 80psi gauge because the reading on the gauge (ie: 0-80 psi) will NOT be accurate.

I only ever use a 0-80 psi oil pressure sending unit in Fiero swaps so the gauge reads accurately. Sure, it may peg out when the engine is cold, but it is still reasonably accurate to the max 80psi range on the gauge. Once the engine is fully warmed up, the 3800 engine will rarely exceed 80psi of oil pressure, if it does at all.

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Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

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TXGOOD
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Report this Post07-09-2015 04:18 AM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks guys, I have an empty windshield gauge pod that I think will take an aftermarket digital gauge just fine.
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