I got all the wiring done. i removed the fuel pump fuse, so I could prime the oil pump. i used the ls1 underhood fuse box and also all the wires that go thru the firewall to the C200 connector including the LS1 ign switch. I just splised the correct wires to the stock ign wires.

I checked that the power is comming into the cabin and the thick yellow wire going to the ls1 relay is getting power in start position. I can also hear the TPS housing click. but nothing else. no power to the starter.

i have not tuned the pcm for vats or anything else but I think i read somewhere that even without removing vats the engine should turn over at least for a sec or so. is this the case?

 

Neutral safety switch or clutch switch?? Did you check the purple wire going to the starter to see if its hot in START to confirm that the starter isnt fried?? Starter relay in??

 

The power to the starter has nothing to do with your ls harness. Just make sure when you turn your key to the start position you are sending current to the starter solinoid. Use the original wiring for the vehicle for this or make connections from your switch.

 

i got all that checked. my question is do i need to tune the stock pcm for vats and other stuff before the pcm will trip the starter relay and energize the starter relay ?

 

no, engine should run for 3 seconds.

 

Thanks guys. I checked and rechecked everyhing u guys suggested but after a couple of hrs of scratching my head thought I would give it a try. It bumped over. .

I am sure it was one of the things u guys suggested just dont know which one ..

So thanks again and cheers !! .

Next I am gona try to see if I can get the oil preasure up. I dont have a universal gauge just the stock 82 gauge cluster . I hope I wired it right and it shows some preasure.

 

You might be wasting your time trying to get oil pressure up before initial startup. It's a completely different style of pump, from the old style smallblock pumps. When I went to start my new engine, I tried to turn the engine over to get pressure up, but it just wouldn't register. Also, on a fresh engine, make sure the filter is dry, not pre-filled. Good luck!

 

why should the filter nned to be dry on a new engine. This was a 40K mile stock engine.

I filled oil in the new filter based on reading on here. then even though the engine only takes 5.5 qts, i put a total of 6 qts including what I put in the filter.

Anyone know what the voltage should ahow on the oil preasure signal wire on the LS1 harness? its a 02 TA harness. ?????????

 

My 2001 4.8L with a Moroso pan and pickup which hadnt rotated in over a year primed itself thru a remote oil filter setup on the inner fender and makes 30 psi of oil pressure on the starter with the plugs out. Thats on my old trusty mechanical gauge I use for priming and confirming.

 

I just got it to crank her for a sec just to check if i got the wiring right.


I am not sure I am getting oil preasure and still no way of checking it. i am still tring get enough info to re-pin my gauge in my 82 ta.

I tried using a DMM but either i am not using it right or its not reading right.
I put it in the 200 ohm setting.
key off : +ive 5-8 ohms
Key on: -ive 110 to 122 ohms.
during cranking : +ive 50-121 ohms.

i took the fuel pump fuse off, to the coil connector and put the ign in start. i would say 6-8 times at 10-15 sec intervals. each time same result.

what can i do ?

 

are you using the '82 sending unit, or are you trying to use the ls1's sending unit? You need to use the 82 sending unit and just connect to the gauge like it was on the '82.

 

my 82 gauge is not working. I have a replacement 91 gauge. I need to repin my gauge connector to match the 91. I have not been able to find any info on the 91 gauge connector pinout yet.

I also need to do the drill and tap mode on the ls1 sending unit.

I was hoping in the mean time, I should be able to use a DMM to measure resistance from the LS1 sending unit already on the block.

what reading should I be seeing ?

 

Although there are exceptions, most LS motors wont register oil pressure just from cranking the starter. When it fires up, if it dosen't prime and register pressure within 3-5 seconds, shut it off. THEN U GOT A PROBLEM!

 

I'm using my factory '82 gauge with the '01 LS1 sending unit, only one wire involved here...the tan one. Don't recall the circuit ID or connector pin location, but I mapped it on the LS1 side and '82 C100 (or was it C207?) side and it's been working fine since 2004.

Just one wire. Same wire my previous '88 TPI swap used.

After you've traced and verified the wire, see LQ9Chevelle's comment. You'll have to crank it for quite a while to build oil pressure, and even then at ~150rpm cranking speed it's unlikely to be enough to move the gauge.

 

If you're trying to reverse engineer the sensor, remove it and hook it up to compressed air instead of trying to crank the engine.

 

My understanding was a gauge(Oil preasure & CT) was a simple Ohmmeter paird with its sender.

I hooked up the tan wire comming from the LS1 Oil preasure sender at the back of the engine to the 1991 gauge (thru the C100 bulkhead connector on the firewall)......no reading whatsoever.

So I was guessing that I need to change the LS1 sender to a 91 sender using an adapter.

Is this not the case ?

 

I'm running '82 dash gauges, so it's possible your '91 instruments are different I suppose. Check your '91 wiring diagram?

 

the 82 and 91 Oil preasure diagram are same except the gauge connector are pinned different.

I redid the pins still no reading.

First time I am reading that a LS1 sender will work with a 3rd gen gauge.

 

I've been running mine this way since 2004, guess I didn't know it wouldn't work.