Don't use mobil oil. You're paying a lot of money for the marketing and don't use 0w ever
help! low HPFP pressure after upgfrading internals and rebuilding!
- Thread starter kayarepea
- Start date
ok so a little update here, and wanted to point out a couple of things that i'm not sure if i mentioned earlier...
i pulled the hpfp back off, pulled it apart again and cleaned it completely with naptha, lubed everything fairly liberally in redline injector cleaner. gave the piston a bit of back and forth as it felt pretty tight, but was careful to make sure i was only going axially. got everything back together, put some ric into the spill valve cavity after the hpfp was installed, then reinstalled the spill valve, initially i hand tightened it, then used a big crescent wrench but choked up on it so i was holding it basically at the head, and just snugged the spill valve on (i read in one of these posts that it should be snugged up decently, but that if you really try, you should be able to barely twist the spill valve in the threaded body.. so i did that, and before i started i primed the electric pump a couple of times before actually firing the engine up. fired her up, she coughed a few times getting the ric out of the hpfp, but seemed to run alright. but the pressure was only at about 500, and that was at a cold start, and as the engine warmed and rpm's came down, the pressure came down too. once it hit about 300, i knew it still wasn't right.
on a hunch, i grabbed my crescent wrench and gave the spill valve a bit more snugness, and when i did that, the clicking of the hpfp got a bit louder, but instantly the fuel pressure went up to about 500 (rpm was still a bit higher than normal idle). let the engine idle for a bit, and as it cycled between about 800 rpm and 830 or so (i think the ac was on lol), the pressure hung out around 500 or so and bumped up to about 670-700 when the rpm's bumped, then it came back to 500. so i took it out for a ride, and it seemed to work alright, but then when i got the rpm up a bit more, the fuel pressure wouldn't go above 1200 or so. i didn't want to push it hard, but with my old OEM internals it would easily hit 1700 psi below 3000 rpm, so i know it's not working like it should. not to mention it didn't seem to matter what i did, it won't go above 1200 psi.
i did notice that the connector for the fuel pump resistor seems to have some electrical tape around it and i'm wondering if maybe ithere's a bad connection in there. debating just bypassing it fully as i've read a number of people have done that with no negative results.
any ideas? really getting frustrated now!
also, just as an aside, i did also throw on a corksport power series 3 inch intake w/ 3 inch MAF, and i recalibrated the MAF using the flow/voltage info from corksport, but did the calibration using versatuner since i can actually do my own stuff with versatuner and i'm not locked out like i would be with corksport's accessport nonsense (really hate that tbh). i did flash a fairly base map before i started up, just to be sure i was not going to risk putting too much demand on the fuel system and end up knocking or something.
but yeah, that's about it. ideas anyone??
btw thanks for all of your help so far i appreciate it very much!
i pulled the hpfp back off, pulled it apart again and cleaned it completely with naptha, lubed everything fairly liberally in redline injector cleaner. gave the piston a bit of back and forth as it felt pretty tight, but was careful to make sure i was only going axially. got everything back together, put some ric into the spill valve cavity after the hpfp was installed, then reinstalled the spill valve, initially i hand tightened it, then used a big crescent wrench but choked up on it so i was holding it basically at the head, and just snugged the spill valve on (i read in one of these posts that it should be snugged up decently, but that if you really try, you should be able to barely twist the spill valve in the threaded body.. so i did that, and before i started i primed the electric pump a couple of times before actually firing the engine up. fired her up, she coughed a few times getting the ric out of the hpfp, but seemed to run alright. but the pressure was only at about 500, and that was at a cold start, and as the engine warmed and rpm's came down, the pressure came down too. once it hit about 300, i knew it still wasn't right.
on a hunch, i grabbed my crescent wrench and gave the spill valve a bit more snugness, and when i did that, the clicking of the hpfp got a bit louder, but instantly the fuel pressure went up to about 500 (rpm was still a bit higher than normal idle). let the engine idle for a bit, and as it cycled between about 800 rpm and 830 or so (i think the ac was on lol), the pressure hung out around 500 or so and bumped up to about 670-700 when the rpm's bumped, then it came back to 500. so i took it out for a ride, and it seemed to work alright, but then when i got the rpm up a bit more, the fuel pressure wouldn't go above 1200 or so. i didn't want to push it hard, but with my old OEM internals it would easily hit 1700 psi below 3000 rpm, so i know it's not working like it should. not to mention it didn't seem to matter what i did, it won't go above 1200 psi.
i did notice that the connector for the fuel pump resistor seems to have some electrical tape around it and i'm wondering if maybe ithere's a bad connection in there. debating just bypassing it fully as i've read a number of people have done that with no negative results.
any ideas? really getting frustrated now!
also, just as an aside, i did also throw on a corksport power series 3 inch intake w/ 3 inch MAF, and i recalibrated the MAF using the flow/voltage info from corksport, but did the calibration using versatuner since i can actually do my own stuff with versatuner and i'm not locked out like i would be with corksport's accessport nonsense (really hate that tbh). i did flash a fairly base map before i started up, just to be sure i was not going to risk putting too much demand on the fuel system and end up knocking or something.
but yeah, that's about it. ideas anyone??
btw thanks for all of your help so far i appreciate it very much!
understood about the mobil 1, i didn't pay a lot for it tbh, it was on sale for pretty cheap. i wanted 0w40 because it gets cold af here, and 0w for startups really can't be a bad thing, and 40 just gives a bit more room on the upper end of viscosity and can give a bit of extra protection to things like turbo bearings, from what i've read on bitog.
what are recommended full synth oil options that aren't crazy expensive? i struggle to justify the cost of something like redline as it's around 20-25 bucks a liter. i do like the idea of redline since from what i know it's still a true full synth and not just a hydrocracked blend, i.e. it's a true group 4/5 blend as opposed to a group 3 blend like most big name "full synthetic" oils. though from what i've read a lot of the mobil 1 european formula's are actually group 4/5 blends still, which is another reason i opted for 0w40.
If you paid more for mobile 1 than Walmart charges for it's house brand then you were ripped off. 0w-40 is going to do nothing for you except be too thin at startup especially since you are going into summer. Unless you are tracking the car and struggling with oil temps or have a built motor where the tolerances in the bearings have been opened up the 40 is doing nothing for you either.
https://mazdaspeeds.org/index.php?threads/best-engine-oil-all-mod-levels.7931/
That's fair, I'll have a look through that thread. I'm surprised seeing the heavier oils but I'm guessing that's for motors that are more built or what?
And a question, if guys are running 10w40 and that's no issue, why would 0w40 be an issue? The 0w just gives a lighter cold and start-up weight with the same level of overall warm protection. Or is it not so much that is the issue as much as the Mobil 0w40 doesn't have the same qualities to prevent detonation at low loads?
But yeah the big concern I have right now is the low fuel pressure. I'm positive the pump is installed all the way and evenly, and everything is in the correct position, so it really isn't making sense to my why the pressure is so low. Took it out today and hit 1500 psi a couple of times but overall the pressure is much lower than it was with my factory internals!
0w exists to help manufacturers pass emissions requirements there is no longevity or performance benefit
Post a log of the fuel pressure
I'm in Manitoba 5w30 all year wether it's it's -45 or +45C, I've put UOA into that thread that Easter bunny linked it's showing good on Pennzoil platinum edit: royal purple was better but it's expensive
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First post but I was on the same boat brother. There is a happy medium for the spill valves 32mm "snugness". When I rebuilt my HPFP according to CS instructions and had some play with the spill valve, just like you, could only get about 200psi on startup and probably 600-800 when I blip the throttle. Then, I tried too tight. Just as you had, can't go over 1200psi. Log your hpfp psi at hot and mess with that 32mm nut and possibly offset the connector so when you get it snug, it'll be at 6 o'clock. No one was ever supposed to rebuild these so there isn't a torque spec but I can confirm that your concerns should at least be resolved with that. Also, you're gonna wanna do some logging and make sure you're not dropping below 1600psi at wot or 60% load.
ok, so first off about the spill valve tightness..... really not sure how tight to go. i tried to snug it up a little more after my last attempt, since after my last attempt i was still not going over 1200 PSI. Well, after a tiny bit tighter (and realistically probably about as tight as I think should be done, assuming the guidance for it is accurate as "snug"), I am able to hit 1739 PSI actual rail pressure with 1669 max requested fuel rail pressure. Something I did find a bit odd is that 1669 requested was the highest requested even after a couple of runs at around 50-75 percent throttle or so. I thought that with the Corksport HPFP internals I would be able to easily see closer to 2000 PSI though; I was getting very slightly higher peak PSI on my factory internals, though I can't say for sure whether or not the actual flow rate on the factory internals was sufficient even with the slightly higher pressure (i.e. i can't recall whether or not the rail pressure dropped off when the rpm got high enough at WOT, or if it was able to stay steady).
But yeah anyhow, I've posted a shorter log with this post, hopefully if one of you guys has a few mins to check it out and get back to me with any suggestions or ideas, I would greatly GREATLY appreciate your help and advice! It's so awesome to have a forum we can come to and chat about these cars as well as relialy get advice on them! I love how it's still such a popular vehicle platform after all this time. After owning mine for a little over a month now I can fully understand why there are people who seem really dedicated to them - they're pretty awesome little cars!
But yeah anyhow, I've posted a shorter log with this post, hopefully if one of you guys has a few mins to check it out and get back to me with any suggestions or ideas, I would greatly GREATLY appreciate your help and advice! It's so awesome to have a forum we can come to and chat about these cars as well as relialy get advice on them! I love how it's still such a popular vehicle platform after all this time. After owning mine for a little over a month now I can fully understand why there are people who seem really dedicated to them - they're pretty awesome little cars!
The 1669 is Mazdas cap for the requested HPFP psi Parameter. As for your 1739 peak, its good to take into account the ECT at the time of pulls. Pressures can vary from variables like temperature and load. Maybe heat soaked?. Also, rather than compare the CS internals ability of nearing 2k psi and your peak on your stocks, its more about the reliabilty of maintaining those constant pressure. Alot of us; i think could say when we had our stock internals that they could reach pretty high pressures but we're not gonna risk our motors. I couldn't look over the log, idk of its because of my phone/ App but judging by how it seems to have improved, I hope your online the way to getting this concern resolved. Btw, here's an image of Mazdas calculations for FP psi.
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More pressure doesn't accomplish anything. The corksport internals flow about 30% more fuel which is what we care about most
I can understand that too. I believe its because in CS instructions, they say when the 32mm is tightend that the spill valve should be able to spin with some effort and that the nut should be snug. Maybe for someone who hasn't done pumps before, could misinterpret that. Those who've messed around and removed the pumps before are probably experienced enough to know that that sucker is on there pretty tight usually and that the valve and connector dont really spin.