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**pocket-rocket** · 08-13-2011, 12:00 PM

Have you checked fuel pressure?

As for the oil pressure, I would check your wiring and possibly toss a new sending unit at it. Or better yet, get a live gauge at the local parts store (~$20-30) and install it in place of the sender temporarily to make sure that you actually have pressure. I've never seen a gauge act like that, and if that was actual pressure I don't see the engine not making some nasty noises.

I had a friend with an older Supra (mid 80s style) that had a defective sender. The diaphragm must have been leaking because if the car sat for a while the gauge worked, but after running the engine for about 15-20 minutes the gauge would taper down to 0, but the engine made no sounds like that of one loosing pressure (lifter tick, knocking, locking up...). What he had figured had happened made sense to me. What was happening was the hole in the diaphragm would allow oil to flow behind itself, equaling the pressure on both sides, causing it to see a 0 pressure differential between each side, so it read 0 while he had pressure.

The bouncing of your gauge, though, sort of mimics the RPMs some, which causes me to think that when the engine rocks from the revving you have a connection issue, be it wire or connector.

BTW, welcome to the site, and I hope this helps and gives you a starting point

**Lite_Drizzle** · 08-13-2011, 12:54 PM

well actually now that you mention it we did check it but it was a bit out of the ordinary because the guy they called said that those vehicles run at 40psi before starting and 45 to 50 psi after but mine did it was running about 3 or 4 psi short but the gauge would move to right at 47 when you pushed the throttle bu it seems to them that the fuel is there the engine just doesnt want to accept it.

But i definitely will check the sending unit wiring and all and that would explain the speratic then nothing but now mine wont get any pressure what so ever for oil

Thanks for the input hope it fixes the problem been stuck without the car for three weeks

**Lite_Drizzle** · 08-13-2011, 04:14 PM

So checked on my sending unit today and it had no ground actually attached it had somehow severed in the middle of it but bought a new one from advance and put it on there but not a change in oil pressure.

But as i was at advance they told that even though i did test the fuel pressure that the fuel regulator may not be allowing enough fuel and/or the injectors are gummed up but i have found a slightly more strenuous problem i will post pictures soon but im going to redo almost everything in my power and get it running better then new (I hope).

**pocket-rocket** · 08-13-2011, 07:10 PM

I would agree with them.

PM superdave (http://60degreev6.com/forum/member.php/6686-Superdave). He does fuel injector cleaning and I hear he does a good job.

**Harry TheHat** · 08-14-2011, 07:59 AM

Erratic intermitant oil pressure a faulty cracked pickup sump or tube in the oil pan would give the you this erratic condition .Sucking up air and oil. any way of getting a pressure guage installed directly ? Computers have a lot of trouble with intermittant troubles they do not always recognize them. the oil leak find it could be a gasquet issue pressurizes oil is ported up to the lifters and upper cylinder area.these ports are sealled by the gasquets.....AS for the amount of pressure someone mentioned 40 lbs a motor will turn over on minimum pressure 1/2 lbs and live as long as you dont punch it .but it must never go dry. hope this helps

**TGP37** · 08-15-2011, 08:22 AM

I wonder, how old is the engine? Oil breaks down under high heat and can coke on passage walls. Like cholesterol in a vein. I haven't seen a full on clog yet but it isn't impossible. Maybe the oil is running through a pin-hole sized passage.

Either way, I often toss in 1/2 bottle of seafoam into the motor oil before oil change about 50-100 miles later. It breaks down the junk and if you have any clogging issues, that may just do the trick.

If the engine is really beaten and dirty I would use 1 full can in a full tank of gas, 1/2 in the oil and the other 1/2 sucked in threw a vacuum line (as directed). A lot of people swear by it, seafoam.

If the issue continues after, then something is broken imho. If you are having oil pressure problems and you have a leak, 90% chance the problem is where the leak is. Or at least downstream of the oil galley. If the oil leak is worse while the engine is running, then you do have pressure.

Find out why you are leaking oil and hope it is as simple as a bad gasket. A cracked block would be bad news, but I would expect coolant leaking as well.

When I can't find the problem after I tried every thing known, I disassemble the engine to the block, clean up all parts and replace worn. Maybe new rings and a cylinder hone, new bearings if needed. Chances are great you run into the problem or even correct it when the engine is put back together. Unless it is a component off the block, but in your case I don't see that being an oil problem.

**Lite_Drizzle** · 08-16-2011, 01:30 AM

true but ur a little late lol

Its really funny after the fact of me getting pissed off at the car to the point where is just simply said fuck it and literally tore it all the way down to the pistons and replaced every gasket and ring on the way back out

But it seemed to me that the problem was that a small portion of coolant passages were blocked of by sediment and such over the years since it was the fist time it had the gaskets and o rings replaced. Though it did catch my eye when i first pulled the intake manifold gaskets off they needed to be replaced earlier on but at least it wasn't a head gasket or something that would've really possibly damaged the engine.

Though you have a good point about the age its still the same factory engine but not if i have anything to do with it but i would definitely be up for any suggestions on what i should do to the car performance wise

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