I'm still stressing about my oil pressure - so much so that I've ordered a mechanical gauge to cross-check it against the VDO sender/gauge. Also been doing a lot of internet-searching and came across this thread. His experience is similar to mine (but, my oil pressure stays around 30, hot) so I don't feel quite so bad.
I'm going to dump the Schaeffer 5w-30 for some 5w-40 Rotella and see if that makes a difference. I'll cross-check the pressure with the mechanical gauge.
If all else fails, I'll put in another shim (dammit, that means pulling the motor AGAIN!!) and see what happens.
I might be wrong, but I'm pretty sure shimming the oil pump will only increase the pressure at which the release valve opens. It won't increase your running oil pressure if it is under the relief pressure
I'm disappointing our oil pressure convo in my build thread died on the vine. I'll PM 18 and see if he can cut out the relevant comments into a new thread in the Engine section.
Yeah, I was expecting more from that, but maybe someone will have something to add later.
Did you see Jeffbucc's recent oil pressure related stuff? Looks like he went with a MUCH thicker oil, seems to have helped.
Nope, but I'll search for it. I've changed out the Schaeffer 5w-30 for Rotella 5w-40 this afternoon. It's helped - the oil pressure has gone up about 3-4 psi, but I still want to see 40+ during normal driving.
The spacer should show up mid week next week. With that, I can get the oil cooled down enough to stay thick.
plumbed with Aeroquip lightweight hose instead of SS braided hose
Result; oil temps dropped 20-30*F in highway cruise - stayed at a rock solid 200-210*F (whereas prior to the cooler, the temps would hover at 220-240*F). All of this without any fancy ducting, just air getting to it from under the bumper. Also, oil pressure now stays at 40+ psi after sustained hwy cruise at 75MPH (I was hoping for it to get above 45, but this is better than nothing - I'll take it).
One side note...on (my first) trip to the garage to plumb the cooler everything was fine until I got on the freeway. Then the car started mis-firing and I thought, "WTF!!" After about a mile it cleared up, but then it reoccurred and got so bad I had to exit. It wouldn't idle, and soon quit completely and wouldn't restart.
I had done a small change to the CL idle initial value table, but that shouldn't have cause something like this. I thought the problem was electrical in nature, so I poked around some wires and un-plugged, and re-plugged some connectors. After 15 minutes of this the car fired right up and ran just fine! My wife was with me and, for her peace of mind, I called a tow truck and got a tow back home.
After getting back home and eating lunch, I packed up my tools and headed for the garage again - this time, without a problem.
I don't know if this was a wiring loom problem, a loose connector (or two), or the beginnings of a coil-pack failure. I do have a spare coil pack that I'll carry with me in the event that this happens again...
Now that it seems that I've got (most of...I hope) the mechanical gremlins dealt with, now come the electrical ones!!
Today I got stuck again with the car backfiring and the RPM signal (among other things) dropping out. There's some kind of intermittent short, or broken wire, or something happening that isn't making itself very visible. I spent about an hour on the side of the freeway entrance ramp wiggling wires and jiggling connectors, but I just couldn't make the problem happen on-demand.
My theory about a pre-coilpack failure were dispelled - I had a spare on hand (this time) but swapping it in didn't make any difference. What I did notice is that the fuel pump relay would click wildly when the problem occurs - I was almost tempted to bypass it to see if the problem was in the relay. But I didn't go that far. I got the car running well enough to get back home, but there were a few sputters along the way.
My next stop is to take a look at the ground wire from the engine - maybe it has come loose.
I'll check that later this evening. Right now I'm gonna chill with some ravioli and a glass of wine...
My attendance at the festivities this weekend are tentative, depending on resolving this problem.
Last night I;
- Cleaned off the place where the ground strap bolts to the firewall
- Cleaned up the bracket where the grounds for the injectors bolt to the IM
- Replaced the fuel pump relay
About an hour ago, I went on my "small loop" (a route I take to test if stuff is working). Everything was great until 3/4 of the way through the loop, everything started going crazy again. I was close enough to get home without being stuck again (the car stalled just as I was pulling into a parking spot).
I pulled out my DVM and opened the main fuse box, preparing to do some wire sleuthing. The first object of my attention was the main fuse, but when I went to remove it I found this;
Well, not exactly this. When I pulled on the top of the main relay, the top came off in my hand! I don't know how long it had been like this, but it couldn't have been doing anything good like that. My guess is that my car's substantial vibrations (I'm running AWR almost-solid engine mounts) caused the top of the relay to dance around enough that it would interfere with the contacts and cause everything to shut down temporarily. I have no idea how the tabs on the top itself got broken.
Anyway, I had some spares (I've had heat-soak problems with the main relay in the past so I keep a couple of spares) and I popped one in. I followed up with a run through the "short loop" without a hiccup. Later on I'll try something a little longer but I'm gonna call this one "solved" (crossed fingers)
Drove up to Alpharetta yesterday (22 mi) and back - no problems with the "new" main relay. All is well.
Installed some frame rails while I was up there and the difference was quite noticeable (even the wife thought so)!.
Also cobbled together some ducting to the oil cooler (no pics), and that made quite a bit of difference. Without the ducting, the oil temps would hover around 220+ during highway cruising. With the ducting, the temps barely went above 200 (the thermostat is a 200* stat) during cruise, and only heat-soaked while at a standstill - but they never got above 220. And the oil pressure went up to a tick above 40psi at cruise and never dipped blow 10 at idle. I'm happy(ier).
I think this one might last...
Next on the hit parade;
- Finish the door panels
- Get some decent sounds in the cockpit
- PAINT!!! (right now I'm rockin' a black hood and front fenders, silver doors, green shell and rear quarters and blue trunk and rear bumper cover..."FrankenMiata"!)
This is a log from when it first happened last Saturday. There aren't any markers, but it first starts happening around 862 seconds (just look for the first occurance of 0 RPM after the startup - it'll be crystal clear).
Searching through the wiring diagrams it looks like the only things on the path of the fuel pump relay (which clicks wildly when this happens) are the relay and the injectors. There's a white/red line that goes to the ECU, which I think is it's main power source, and that white/red wire also goes to the cam sensor.
Plan of attack;
1) Jumper the hot leads of the main relay so that it's out of the picture as a suspect (I've had problems with that in the past heat-soaking and causing the car to crank but not fire). If the car works reliably, I know how to deal with that...I've got a HD switch, I'll be my own main relay.
2) If that fails, check the injector wiring. I have splices for the FIC 650 injectors - one or more of those might be shorting out. Find and fix any issues there.
3) If that fails, replace the cam sensor (might just do that on GP).
Damn man that is hard luck you have been having. If there is anything I can do to help ,drop me a line. Glad at least part of your week went well.
You ain't seen nothin' yet;
- Saturday; thought I had the whole electrical thing solved. Went out for a test drive. Not only was the problem still there, but I managed to leave my phone and wallet on top of the car. I was blessed enough to recover the wallet (relatively) unscathed, but the phone was smashed to pieces. A replacement is coming Tuesday.
- Sunday; discovered that the hole that the crank sensor bolts to was stripped!(??) - crank sensor was loose...loose enough that it contacted the trigger wheel. Crank sensor was "groovy" (as in, there was a 1/8-in groove in the face of the sensor where it contacted the wheel). Tapped the hole 1mm bigger and replaced the crank sensor with a spare - glitch resolved (yay)! Went for a test drive, all was well (double-yay!). Came off freeway exit ramp where a nice guy brake-checked me...our bumpers kissed. My nifty (fiberglass) nose is crunched and the front support is pushed back about an inch (boo!). We decide to settle up w/o getting insurance involved (thank you lawd!). Was in the garage until 1AM trying to get the hood to close. Now it closes, but won't open without assistance - this'll need "professional attention".