edit (sorry didn't catch the VATS instead of VAT before posting)
91 RS TBI

I get no MIL/Check Engine/Service Engine light when I turn on the key.

would a blown fuel pump fuse do that?

This car is 1 week old to me (not yet a tagged car) and I am new to this electronic stuff, but I believe I blew the fuel pump fuse last night while changing out the oil pressure switch (OPS) - I had no Idea that the fuel pump was tied to the OPS, makes sense but... I will find out after work tonight if it is blown, I did not know where the fuse was until today. I'm pretty sure its the fuse cause the fuel gauge is pegged past full. I just find it hard to believe that a blown fuel pump fuse would disable the MIL.

(and don't get me started on how much a PITA changing the OPS was and If I had known that there was power to the OPS even with key off, I might have taken more care about it coming into contact with the body, hindsite....)

If that does not work, I'm going to need info on the VATS.

Will VAT disable fuel if a door is unlocked with out the key??

The night before I locked the keys in the ignition (in off) and was able to
unlatch the driver door lock via a small gap near the door latch, I retrieved the keys but never turned on the ignition after that until after I replaced the OPS. The security light does come on as well the air bag inflate, and the car will turn over, just no fuel. I don't think its the VAT because the engine will turn over, but I'm still going to need info about that stuff.

I'll do a search hear for VATS and see what I find, but if anyone has other info, I'll be glad to read it.

Thanks for reading
Mark

 

Yes, the fuel pump on your 91 RS shares a fuse with some gauges and even ECM. That explains why the car won't fire and why you have no gauges and most indicators.

The fuse should be called "Gauges". Replace it with a 10A fuse and you should be ready to go.

And no, VATS does is not tied to doors or door locks at all. The only purpose of VATS is to prevent the engine from running if it's started with the wrong key in the ignition (or with no key).

Hope this helps.
Lou

 

The only fuse that would apply to the fuel system besides the INJ1 & INJ2 (INJECTOR) fuses would be the 20 AMP inline fuse located near the battery in the engine compartment and it is for the fuel pump relay, ECM, and oil pressure switch/sending unit. If it blows, the car will crank but the fuel pump won't work because of the fuel pump relay and the ECM. This small insignificant fuse has caused many a person to change their fuel pump for no reason. BTW, I forgot to mention that this fuse will cause you not to have a check engine light because there is no power to the ECM.

 

Yep, fuse was blown. fired right up when replaced.

I knew that I had probably blew a few when I was changing the oil pressure switch and it grounded out against the body while i was wrestling with it to get it off (the new one is a little shorter and allowed the socket to go on better), but I did not know where it was, and neither Chilton or Haynes made any commit to it's location, only that it was fused.

Thanks all and thanks thirdgen.org for having this site.

Mark