Boostage

I have an autometer oil pressure guage, the electrical one. and after work I started the car up to go home and it started to flicker, going from idle pressure to to a bit higher really fast. I waited until it looked like it was done doing that then checked the oil level, not a drop is missing so I proceed to drive home and it it reads the normal 50psi but flickers again, then a half way to my house at the stop light it started to flicker the other way, it would go to 0psi and back up to 18psi like super fast

even though the engine is obviously getting suffcient oil. so I gave it some thottle, and each time I get on it it drops to 0psi and when I back off it goes up back to 50+psi. and then flicker between 50psi and 55psi. get back on the gas and it drops down to 0psi.all this happens super fast. what the hell is wrong with the guage?

BoostedEG6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">I have an autometer oil pressure guage, the electrical one. </TD></TR></TABLE>

thats the problem right there..... get a mech. one or a different gauge. The Autometer gauges tend to have problems like what you are having

Boostage

I have a feeling its some kind of weird grounding issue because it flickers to the beat of the idle if that makes sense, basically my car pulsates kinda like a drag car. on aem it shows my idle fluctuates between 1000 and 1200 rpms and the needle flickers for every time the revs drop or go up.

Boostage

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">thats the problem right there..... get a mech. one or a different gauge. The Autometer gauges tend to have problems like what you are having</TD></TR></TABLE> Im just going to get Defi's. Im not buying another autometer. but where do I begein to fix this problem for now?

BoostedEG6

Check all your wiring and what not make sure nothing has come loose

Boostage

Today the guage stays at 0psi no matter what, I looked at the sending unit, and ther eis a wire on it held by a nut, bot for the life of me I cant find a ground anywhere. I follwed the wire from the a piller, thru the firewall and I still cant find it. wtf?

RTW DC2R

where is the sending unit mounted?

definitely sounds like a grounding/wiring issue to me. did you use solder or did you crimp any connectors?

are any other lights/gauges flickering at all "to the beat" of the idle? Could it be battery/ground related?

notoriousB

the sending unit is grounded to the block via the pipe thread connection.

BoostedEG6

**edited because came out wrong**

here is a diagram for the wireing




Modified by BoostedEG6 at 3:03 PM 8/4/2006

notoriousB

that's not a ground wire to the sending unit it's the signal wire. the sender is grounded to the block.

Boostage

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notoriousB &raquo;</TD></TR><TR><TD CLASS="quote">that's not a ground wire to the sending unit it's the signal wire. the sender is grounded to the block.</TD></TR></TABLE>

so what do I check?

BoostedEG6

I am betting that you gauge had taken a **** on you..... have you tried to rewire everything? It shouldnt take that long to redo

notoriousB

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">so what do I check?</TD></TR></TABLE>
I have a similar sending unit (canister style) on my S10 and when I installed the 350 the gauge pegged to FULL (100+ psi) - turned out the signal wire connector was touching the sending unit housing, causing a short. Bent it away and it worked properly. Unfortunately you're experiencing the exact opposite.

I would assume that you're experiencing a wiring problem, or your sending unit is not getting a proper ground.

Do you have your oil pressure sender attached to a T to your block or is it remotely mounted? I have heard of people having poor grounds on their senders due to a remotely mounted pressure sender. (the braided line did not transmit the ground well)

You can try grounding the sending unit to the block/chassis using a simple jumper wire. If the gauge has been working for a while and this is a new occurrance my money is on a wiring problem. It could be as simple as a bad ground to the gauge itself. Trace your wires, check for continuity to ground on ALL wires (not just grounds).

Boostage

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notoriousB &raquo;</TD></TR><TR><TD CLASS="quote">
I have a similar sending unit (canister style) on my S10 and when I installed the 350 the gauge pegged to FULL (100+ psi) - turned out the signal wire connector was touching the sending unit housing, causing a short. Bent it away and it worked properly. Unfortunately you're experiencing the exact opposite.

I would assume that you're experiencing a wiring problem, or your sending unit is not getting a proper ground.

Do you have your oil pressure sender attached to a T to your block or is it remotely mounted? I have heard of people having poor grounds on their senders due to a remotely mounted pressure sender. (the braided line did not transmit the ground well)

You can try grounding the sending unit to the block/chassis using a simple jumper wire. If the gauge has been working for a while and this is a new occurrance my money is on a wiring problem. It could be as simple as a bad ground to the gauge itself. Trace your wires, check for continuity to ground on ALL wires (not just grounds). </TD></TR></TABLE>

The sending unit is coming from a T off the block and its been working fine for 2 months. I will check the grounding.