drscottsmith

I am ever so much closer to a first start of the 951 project but need to verify something I have studied on the wiring diagrams…

I tried to crank the car briefly last weekend for the first time since I have owned it. Starter ran fine and no weird noises from the engine which I take as a good sign.

my dash is still not working correctly, so I have no oil pressure gauge to verify that the oil system is working (it has been primed). I have disassembled the CE panel and it was an absolute mess so hopefully that will fix several things

here is the question then…
the Instrument panel fuse is fed from the G2 relay, which is the load reduction circuit that DISABLES when the car is in start - so how on earth would I verify oil pressure at the gauge with the fuel pump fuse removed just to build the pressure up? I have read that one should see full pressure within a few seconds of cranking - am I missing the workaround?

931guru

No. The gauges are fed through fuse 18, which is powered by the KL15 circuit, directly from the ignition switch.

You can verify by measuring voltage at fuse 18 when ignition is on and when key is in start position.

drscottsmith

OK thanks guru - I was under the impression that KL-15 WAS the load reduction circuit and would off during cranking.

931guru

The KL-X circuit is the one that does that.

Tiger03447

Gents: Does the oil pressure light go out while cranking? If it does, then you either have. a bad gauge or sender, or wiring. My gauge quit working on my car, but because the idiot light went out, I presumed one. Of the three (or mor probably) was/were the culprit.😀HTH some.

drscottsmith

Hey Tiger -

some updates for you and to the thread in general.

so I do not have any lights on the dash with ignition on, other than the low fuel and the volt gauge - no volt lite, nothing on oil pressure, nothing on temp, and no “!”. My understanding is that all of those should come on with ignition and then go off when car starts - so something is still up.

so an update on my car - I disassembled, cleaned and rebuilt the fuse box. It was a mess. Although cleaning it had no benefit to the gauges. I think something is amiss from my new wiring harness for the microsquirt and I need something in the cabin connected that is not.

I tested the wiring and all is good — disconnecting the oil pressure gauge sender causes it to peg high (normal) and grounding it brings it back down. Grounded the other lead for the light, and the low pressure light and the “!” Come on as I understand they should. So wiring related to gauges, wiring and fuse box checks out.

so I connected a manual pressure gauge to the sender tap. Nothing on cranking. Checked the torque on the crank bolt - spot on at 155 ft/lbs. I have tried to prime the oil pump multiple times to no avail. I would like to find a way to test oil flow before pulling the oil pan and front of engine again.

I need to know what I would expect to see happen if I were to crank the engine over with the pressure sender fitting removed (e.g. oil pump out)? Same with no oil filter - should I see oil pump out through the center or side hole if I am getting pressure?

next step is to pull oprv and make sure it is not stuck - assuming I would see oil flow there if pump is working.

all for now

mel_t_vin

If you crank the engine with the oil filter removed [and DME relay pulled to prevent the engine from starting/running], oil should come out of the side orifice. The center orifice is the supply to the rest of the system.

931guru

If you have lost the prime to the oil pump, you can use an air gun (with a rubber tip) inserted into the dipstick tube to put a little bit of air pressure to help the oil into the pump. Also, you might add a bit of oil into the oil filter housing to try to back fill the pump. When the pump is dry, it is tough to get it primed.

drscottsmith

Thanks all - An update and I hope the problem solved.

Pulled the OPRV and it slid in and out just as I believe ti should - no resistance at all. So I marked that off the list. Then I decided to investigate the front end of the crank again and when I discovered what was going on.

For the micro squirt conversion, I am using a trigger wheel mounted to the crank. I really did not want to cut up the belt covers and be able to continue to use them, so I got a wheel that is larger than the alt and balance shaft pulley. I chose to mount it between the alt pulley and PS pulley using standoffs that maintain equal tightening using the 4 bolt holes in the alt pulley for attachment. What I neglected to consider, however, was that this setup added about 7mm (bolt heads that do not fully rest underneath the PS pulley lip and the depth of the trigger wheel itself. Since the trigger is BETWEEN the PS pulley (which the crank bolt tightened down against) and the alt pulley, I was putting 155lb ft against the sandwich of pulleys and the torques was never making it to the timing belt gear and pulling it up against the washer and o-ring that generate the grip between the oil pump drive and crankshaft.

So now I am adding a spacer underneath (behind) the PS pulley to make up the difference - and allow the PS pulley to tighten down against the rest of the pulleys before bottoming out on the trigger wheel.

Will let you all know once this is complete - crossed fingers!