trwebb26 Posted August 6, 2006 Share Posted August 6, 2006 I just finished re-wiring my car with a 7 psi oil pressure - fuel pump cutoff. When the motor is cold - everything stays running, but when it warms up - every time I go to idle the oil pressure drops just below 7 psi and it dies (like it is supposed to). I'm running an autometer electric guage w/ new sender - so I'm sure I have low oil pressure. After searching - I've read 10 psi for every 1000 rpm. Is oil pressure below the 7 psi marker at idle too low? Where should I look to fix it? New oil pump? New springs? Drop the pan and check the screen? Suggestions? Thanks for the replies. Quote Link to comment Share on other sites More sharing options...
rztmartini Posted August 6, 2006 Share Posted August 6, 2006 I heard that if you put a very thin washer the diameter of the spring in the oil pump it will increase your oil press. same thing as getting a stiffer "turbo" spring. you will have to experiment on what thickness to do, as i have not doned this yet (engine not running yet) and since you have a good gauge you can watch for too much pressure. Quote Link to comment Share on other sites More sharing options...
dapiper Posted August 7, 2006 Share Posted August 7, 2006 Don't worry unless you have less than 50 psi at 3k RPM Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted August 7, 2006 Author Share Posted August 7, 2006 The problem is... my car won't run unless the oil pressure is above 7 psi... I looking for advice so I can have higher oil pressure at idle. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 7, 2006 Share Posted August 7, 2006 Shimming the springs will work, as would buying either a Nissan Comp inner or outer spring and replacing one of the stockers. I think right now I'm running the stock outer and the Comp inner. My pump was modified to make it adjustable. The big plug that holds the springs in was drilled and tapped and a large probably 12mm bolt with the head cut off was installed in the plug. There is a notch for a screwdriver and a jam nut on it. Basically you loosen the jam nut and you can twist the bolt in or out and change the preload on the oil pump springs. Works good. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted August 7, 2006 Share Posted August 7, 2006 A pressure switch set at 5psi would also work. Less than 5psi would be trouble. Shimming the pump is not all that difficult. If you go that route then use a thinnnn washer. Excess pressure is not needed or advised. Quote Link to comment Share on other sites More sharing options...
eec564 Posted August 7, 2006 Share Posted August 7, 2006 I'd perfer to go with a stiffer spring in oil pump over changing your low-pressure engine kill. You may also want to check the tolerences in your oil pump. My 83 SD gets no less then 12psi at idle with 20W-50, and my dad's 84 SD no less then 10psi with 15W-40. What pressures are you getting at higher RPMs under load? Edit: My ZX with 10W-40 Synthetic has 15psi hot at idle. Quote Link to comment Share on other sites More sharing options...
racerx260 Posted August 7, 2006 Share Posted August 7, 2006 Are you using the high volume turbo oil pump?. what weight oil are you using?.I tried the other springs but you have to be careful when the oil is cold pressure is way high.Have to let it warm up some before you rev out. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 7, 2006 Share Posted August 7, 2006 Are you using the high volume turbo oil pump?. what weight oil are you using?.I tried the other springs but you have to be careful when the oil is cold pressure is way high.Have to let it warm up some before you rev out. I had this same problem. anything over idle when cold would peg my oil pressure gauge. Changed to one comp spring and one normal spring and it was better than stock and not super pressurized like running both. Quote Link to comment Share on other sites More sharing options...
racerx260 Posted August 7, 2006 Share Posted August 7, 2006 did you use the inner or outer spring? Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted August 7, 2006 Share Posted August 7, 2006 I do like Jon does and run the Comp inner and stock inner. Seems to be the most practical with a street engine. Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted August 8, 2006 Author Share Posted August 8, 2006 There is 78K miles and 28 years on the stock oil pump... I decided to retire it and ordered a new Melling Auto/Turbo oil pump today. It should be here Thursday. I'm running 10W30 oil. I'm running megasquirt w/ no idle air control - so I can't really drive it until the engine warms up anyways. Where do you get the stiffer "comp" spring? It probably wouldn't hurt anything to run the stiffer spring right from the get-go like you guys recommend? Thanks again for all of the replies! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 8, 2006 Share Posted August 8, 2006 You get the "Comp" spring from... Nissan Competition Dept. I am also using the comp inner spring with the stock outer, but I think it works either way. Courtesy Nissan has the whole comp catalog on their website here: http://www.courtesyparts.com/nms/s30/index.html and here's the springs: http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=CP&Category_Code=s30_nismo_oilpumpspring For the record the comp pump is just the higher volume turbo pump with the comp springs. Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted August 8, 2006 Author Share Posted August 8, 2006 Thanks for the quick reply! Surfing through the website - 90% of the stuff isn't for sale any more! Anything else on the website good to consider picking up while I'm paying the shipping charges? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 8, 2006 Share Posted August 8, 2006 Tough to say, what else do you need? Quote Link to comment Share on other sites More sharing options...
eec564 Posted August 8, 2006 Share Posted August 8, 2006 If you want simple extra air added for megasquirt, there's an auxillary air regulator on the ZX you could add that runs off the fuel pump relay. It has an element in it that closes a shutter as it heats up and stops the extra air flow, no control by megasquirt needed. Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted August 8, 2006 Author Share Posted August 8, 2006 Courtesy doesn't have the springs and they are on back-order for another 4-6 weeks. Anybody else I could call for the springs? Quote Link to comment Share on other sites More sharing options...
Pyro Posted August 8, 2006 Share Posted August 8, 2006 Shimming the spring or using a stronger spring will not help idle pressure. The spring doesn't effect pressure until a high enough pressure is reached. And idle pressure is way under any relief pressure. The problem is that your engine has too big of a clearance in the bearings for your stock oil pump with the oil you are using. So, either use thicker oil (10-40W, 15-40W, or 20-50W) or use a turbo oil pump that pumps more oil per revolution due to longer pump rotors. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted August 9, 2006 Share Posted August 9, 2006 Good point Pyro. Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted August 10, 2006 Author Share Posted August 10, 2006 My pump came in a day early. Sad to say that it didn't fix the problem. When the car warms up - it idles too low. I've decided to switch to a higher weight oil. What oil weight do all of you guys run in your Z? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.