Hybrid Help LIM (sending unit in the way)?

[ghrarhg]

Trying to put the 3400 LIM on, and I'm hitting what looks like an oil pressure sending unit. Here's a pic of my block.



None of the hybrid threads or guides mention this. Is this another pressure sending unit? If so, what does it send to?

[bszopi]

I don't ever remember a sensor being mounted in that location on any of these engines I've ever worked with...

[ghrarhg]

I don't ever remember a sensor being mounted in that location on any of these engines I've ever worked with...

That would be my luck on this swap.

From the pictures I've looked through, I've only seen it on another 88 2.8 GP. Is is possible they used 2 oil pressure sensors, 1 for the ECM and 1 for the cluster?

I'm thinking I may be able to 45 it or 90 it out of the way, but there's not a whole lot of room in that area.

[Superdave]

pull it out and plug it.

If you still end up needing to have it hooked up then you can either T off the one on the oil filter adapter or get creative with the wiring.

[PCGUY112887]

WTF is that? What block is this?

[ghrarhg]

This is a 1988 2.8 FWD block.

[ghrarhg]

OK, turns out it's an oil pressure switch for the fuel pump.

I'm not really familiar with this on other cars. Is this common?

I tried a street 45 elbow, and it still hits the LIM. it doesn't look like there's any way I can get a fitting around it. Plugging it may be the only choice...

[IsaacHayes]

Yeah plug it and be done with it. You may have to solder those wires together to get the fuel pump to run. Looks like it only lets the fuel pump run when it sees oil pressure as a safety measure. I don't think the newer cars use something like that anymore.

[ghrarhg]

It's actually a fail-safe for the fuel pump relay so you can get home. Basically it's a normally open switch that once 4 psi of oil pressure is reached, the switch closes. The text says that if the fuel pump relay fails, the engine has to crank a few extra seconds, 4 psi is hit, switch closes, fuel pump gets power and you can drive home.

Sounds like I can just plug it and be on my way, but I kinda like the redundancy idea.

[Superdave]

that's integrated into the later sensors, 88 is an odd year but 90+ have the OPSU in the oil filter adapter. '89's are in a weird spot.

If your oil filter adapter does not have the spot for it then let me know, i have a couple gen2 adapters around here.

[ghrarhg]

That's the weird part. I have another OPSU in the oil filter adapter, and that's the one that goes to the gauge/idiot light. Maybe they operate at different voltages? Both of mine are 2 wire. Aren't newer ones 3 wire?

[Superdave]

That's the weird part. I have another OPSU in the oil filter adapter, and that's the one that goes to the gauge/idiot light. Maybe they operate at different voltages? Both of mine are 2 wire. Aren't newer ones 3 wire?

the 3 wire ones are for the fuel pump relay and a pressure gauge. thats what my 89 and 91 have.

[IsaacHayes]

I wonder if it's possible to re-wire the two sensors for use with a 3 wire sensor, much like I did with my two coolant sensors (1 wire for gauges, 2 wire ECM) to use the 3 wire 96 style.... ??

I bet you could....

[Superdave]

a T fitting on the filter adapter would let you run both and not worry about wiring... lol

[IsaacHayes]

Bah!!! The extra sensor is extra weight!! hahaha