B C Posted July 22, 2013 Share Posted July 22, 2013 I decided to go for a cruise in the Reatta today. Started the normal way as of late (Fires up then loses RPM until it slowly just dies unless you tap the gas). Everything looked fine until it got up to operating temperature, then I noticed while I was idling my oil pressure would drop to 22 PSI and then go up to 30, then to 24 etc. As soon as you give it gas it will increase to the usual 40-60 PSI from 1200-2200 RPM. But as for the idle pressure, alot lower than usual. Ive never seen it drop below 30 before. Usually I idle between 32-35 PSI. The only thing I have changed recent is the ignition, wires, and plugs. (Switched to Delco unit, MAN can you tell the difference at low RPM!)I also cleaned out the EGR Valve and put new gaskets in as I noticed some smoke coming from it when I cleaned my injectors. That was a week ago and even after doing the Delco upgrade it hasnt dropped oil pressure until today...Not to sure where to go from here. Im taking it in tomorrow because of the 100rpm surges at idle and for a couple other things. Should I just get them to check or could I run some easy tests myself to cancel out some problems? Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted July 22, 2013 Share Posted July 22, 2013 You should clean your IAC to see if it cures your erratic idle before you throw money at the man.IAC Cleaning Instructions - Reatta Owners JournalThe oil pressure senders are noted for becoming erratic too, but only showing low at idle leads me to believe you have a worn spring in the oil pressure regulator or worse yet a bearing issue. Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 22, 2013 Share Posted July 22, 2013 if i recall correctly, the oil pressure sensor "takes over" from the fuel pump relay after starting. mine was bad, finally showing 0 to 255 psi pressure on the CRT. perhaps yours is going out. that's where i would start - might be that's where both of the issues are coming from - if not the IAC for the idle.also a compression check on the cylinders. the rear 3 are a PITA to get to, but if any of the front 3 show a vast difference of compression, then it would be time to investigate the internals before you go back there:)... Link to comment Share on other sites More sharing options...
B C Posted July 22, 2013 Author Share Posted July 22, 2013 Thanks, ill put a new oil pressure sensor in and do a compression test and see how that goes after I get it back. ill try to do it before I take it in but I doubt I can find a new sensor in this hell hole. thanks guiseps I've cleaned the iac and MAF sensor with no results Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 22, 2013 Share Posted July 22, 2013 since i've heard you can't get "The Reatta Store" parts via Amazon in the "Great White North" - i don't know why - i can get Tuborgs here:p, here's a couple links: Buy BWD Engine Oil Pressure Switch S4151 at Advance Auto PartsDuralast/Oil Pressure Switch (PS298) | 1989 Buick Reatta 6 Cylinders C 3.8L FI OHV | AutoZone.comthey are "special order" here, so it would take at least overnight to get them to my store... maybe a NAPA type flaps, or a GM dealer may have them in stock up there... hope this helps! Link to comment Share on other sites More sharing options...
B C Posted July 23, 2013 Author Share Posted July 23, 2013 Way ahead of you, I already picked it up! came to 67$ cad so approx 60$ usEdit: a few places carried them but not in stock. Managed to grab on to one from a small flaps store here. Link to comment Share on other sites More sharing options...
B C Posted July 23, 2013 Author Share Posted July 23, 2013 Also yeah price difference is a lot, but winter is coming fast and Canadian shipping likes to take its sweet time. Link to comment Share on other sites More sharing options...
B C Posted July 23, 2013 Author Share Posted July 23, 2013 Would one of you lovely gents send me in the right direction to install this thing. I have no idea what I'm doing and can't find much online for the series 1 Link to comment Share on other sites More sharing options...
Machiner 55 Posted July 23, 2013 Share Posted July 23, 2013 (edited) Brendan,Oil Pressure sender location.Pic #1.) Pic #2.) In pic #1) Just left of the water pump housing and below the power steering pump.It's the silver tube like thingy with a hex base and black plastic top.In pic #2) Looking down, leaning over the right side fender, the black plastic top of the oil pressure sender, with the four pin connector, can be seen just to the right of the R.H. CV joint.John F. Edited July 24, 2013 by Machiner 55 Added annotation to pics #1 & #2. (see edit history) Link to comment Share on other sites More sharing options...
B C Posted July 23, 2013 Author Share Posted July 23, 2013 Is there a special took I need or do I just loosen (what looks to be some kind of) a nut at the base? I thought I read in a forum that it needed a special tool, is this true? Link to comment Share on other sites More sharing options...
Ronnie Posted July 23, 2013 Share Posted July 23, 2013 No special tools needed. Remove the electrical connection. Don't try to twist on the back part. Put a wrench on the metal hex to loosen. I have changed with a pair of channel locks when correct wrench wasn't handy. Link to comment Share on other sites More sharing options...
NCReatta Posted July 23, 2013 Share Posted July 23, 2013 No special tools needed. Remove the electrical connection. Don't try to twist on the back part. Put a wrench on the metal hex to loosen. I have changed with a pair of channel locks when correct wrench wasn't handy.<img src="http://forums.aaca.org/attachment.php?attachmentid=204755"/>I used channel locks on the last one I did. The new one had a bigger hex head than the old one as well. Link to comment Share on other sites More sharing options...
Ronnie Posted July 23, 2013 Share Posted July 23, 2013 Just a note. The threas on teh sensor are tapered pipe threads. No o-ring or seal is needed. Tighten down good and it shouldn't leak. Go back an tighten a little m ore if it does. Over tightening can deform the pipe threads and make them more prone to leaking. Link to comment Share on other sites More sharing options...
B C Posted July 24, 2013 Author Share Posted July 24, 2013 Changed the sensor, now it shows 46psi no matter what I do.. is the sensor faulty? It only goes up to 47 when I drive past 2000rpm Link to comment Share on other sites More sharing options...
harry yarnell Posted July 24, 2013 Share Posted July 24, 2013 47# is fine. What does it show with the ignition on and the engine off? Link to comment Share on other sites More sharing options...
Machiner 55 Posted July 24, 2013 Share Posted July 24, 2013 Brenden,What does it read at idle? Is there fluctuation in pressure or does the pressure hold steady at a given, set RPM?John F. Link to comment Share on other sites More sharing options...
B C Posted July 24, 2013 Author Share Posted July 24, 2013 It reads 43 psi at idle now after taking it for a drive. I noticed it move a bit more. With engine off its at 0.edit: seems to only fluctuate 5 psi Link to comment Share on other sites More sharing options...
KDirk Posted July 24, 2013 Share Posted July 24, 2013 Sounds like it is operating normally, if the sensor stuck at a set reading it wouldn't zero at engine off.KDirk Link to comment Share on other sites More sharing options...
B C Posted July 24, 2013 Author Share Posted July 24, 2013 Ok good thanks. What does closed and open loop mean? I got an electrical warning screen but no code. I go into service mode and it shows its in open loop (which I've never seen) and the oxygen sensor doesn't move from .81.. this can't be normal Link to comment Share on other sites More sharing options...
60FlatTop Posted July 24, 2013 Share Posted July 24, 2013 Here's the oil pressure on my '86 3.8 Park Ave. It is best to use the gauge. The new engine came with the wrong timing chain cover gasket and partially blocked the oil port. It was only running about 8 PSIG upon installation- good thing we checked with the gauge.We had to find the correct gasket and R&R in place.Bernie Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 24, 2013 Share Posted July 24, 2013 (edited) Brendan, your oil pressure reading(s) also seems to me to be ok.. mine runs a little higher (50+) when cold, then around 47 warm at speed. upper 30's after that at a "hot" idle.regarding open & closed loop, i'll the the "puter experts" explain. all i recall is reading something that it changes at around 140F.i "googled" "open loop vs. closed loop" - this is the first thing that popped up: Definition of Closed Loop vs Open Loopsince the link is about furds, the figures could be totally off - or the whole thing...have you replaced your O2 sensor?EDIT: agree w/60FlatTop on using a "non-electronic";) gauge before going further if the problem resurfaces... Edited July 24, 2013 by Corvanti (see edit history) Link to comment Share on other sites More sharing options...
B C Posted July 24, 2013 Author Share Posted July 24, 2013 That definitely helps, thanks.Yes the 02 sensor was replaced a couple weeks ago. Now that I know about closed and open loops I understand why the oxygen sensor was at that same reading. Link to comment Share on other sites More sharing options...
wws944 Posted July 25, 2013 Share Posted July 25, 2013 Basically the engine runs in open loop when cold. The ignition and fuel are set via lookup tables in the computer. Once the engine has warmed up a bit, the O2 sensor in particular, the computer can use the various sensors to fine tune the ignition and fuel for {power, mpg, min emissions} - depending on situation. It is the reason O2 sensors are now 'heated' at startup. Helps get things into closed loop sooner. (California-bound cars got heated sensors a couple of years before the other 49 states. Of course heated O2 sensors cost about 2x what non-heated sensors cost...) Link to comment Share on other sites More sharing options...
padgett Posted July 25, 2013 Share Posted July 25, 2013 (edited) As I recall going from open to closed loop is on a timer: 125 seconds from cold start and 25 seconds from hot. This gives time for the O2 sensor to fire and is a function of EGT and not coolant temp.. The computer also does a few things at a coolant temp of 146F like TCC enable and is "all in" at 158F. I run mine with a 180F thermostat and reprogrammed fans to keep coolant temp under 190F. Everything under the hood lasts longer.I have noticed that the "C" engine in the Reatta always seems above the factory spec of 40 psi at 1875 rpm and usually see above 40 at hot idle.The FSM recommends using a mechanical gauge if in doubt, the oil pressure senders are notorious for going bad and giving false readings. Edited July 25, 2013 by padgett (see edit history) Link to comment Share on other sites More sharing options...
B C Posted July 27, 2013 Author Share Posted July 27, 2013 Got it all figured out, thanks! She holds steady at 40-44 PSI at idle now and 46+ at 1800 RPMI still think my engine runs rich though, is this all electronically controlled on these cars or is there a way to tinker with it manually? Link to comment Share on other sites More sharing options...
padgett Posted July 28, 2013 Share Posted July 28, 2013 Well some sooperdooper all-in-one perfornace chips add a resistor to the coolant temp so the engine thinks it is cokd but that makes it run rich.Main thing you can do is to make sure the secondary ignition and O2 sensor are new, the MAF is clean, the coolant and IAT temps read right, and you have no vaccuum leaks.The fuel maps are all in the PROM but you can monitor Block Learn and Instantaneous fuel readings, they should be in the 128-132 range at a steady cruise over 50. Link to comment Share on other sites More sharing options...
B C Posted July 30, 2013 Author Share Posted July 30, 2013 Driving today it starting acting out again while I was at a stop light. Kept shooting up to 66-68 psi and it wouldnt drop below 45 at idle. Would shoot up to 68 then down to 55 then up to 64... Is this the same problem :/ Link to comment Share on other sites More sharing options...
harry yarnell Posted July 30, 2013 Share Posted July 30, 2013 Change out the sensor. Link to comment Share on other sites More sharing options...
B C Posted July 30, 2013 Author Share Posted July 30, 2013 I did last week! It would stay in the 40psi range and all was good. Do you think this one is failing already? Defective maybe? Link to comment Share on other sites More sharing options...
Guest Corvanti Posted July 30, 2013 Share Posted July 30, 2013 it may be time to pick up a oil pressure gauge as shown in post #20, to make sure the readings you're getting are accurate.the only "easy" thing i can think of offhand may be to clean the electrical plug connection with "CRC QD Electronic Cleaner". mine worked fine when i replaced it, so i didn't pursue it further. hopefully, the electronic experts will have more to say... Link to comment Share on other sites More sharing options...
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