First, where is the fuel pump power grounded? Inside the car, back by the tank, up by the engine? This was a carb'd car, I've never had to trace down EFI electric pump wiring before. Second, any idea what this part is? The engine/trans seller wrapped the MAF in plastic wrap, and wrapped with it was the IAT sensor and this part. The connector is identical to the TPS sensor. The other end is threaded. (Sorry, the camera didn't focus very well)

the guys at www.ls1tech.com might be able to tell us

Looks like an ac pressure switch for the high side?????

I was wondering about the AC. But I can't find a connector for it. Perhaps part of the chassis harness?

my pump is grounded on the seat mount for the back driver's bucket.

I figured the pump power ground wouldn't be too critical, but inside the car makes sense.

Maybe so. Left-center of photo? http://i57.photobucket.com/albums/g2...5/DSCF0059.jpg

i'll second just going to a solid chassis ground on the fuel pump.

i have another "dumb" question but can't seem to find the answer. i'm trying to wire up a Malfunction Indicator Lamp using an led i got from the parts store. i've already drilled the hole in the dash bezel for it so i'd like to use it, lol. i found the wire going from the pcm to the SES light, but when i wired it up to the light (signal wire to one side of the led, ground to the other side) i got nothing, and i know i've got trouble codes. i scanned the car and it read out that i have a MIL code, did i hook up my faux SES light incorrectly?

also, it appears that i have a pretty nasty lifter tick, what is everyone using for new lifters? looks like i get to pull the motor back down

definitely a pressure switch. I would go with a nice solid interior ground for the pump.

for mw66nova check ls1tech.com seems like folks are running ls7 lifters quite often now.. Morels are the billy bob bada** lifter but cost a ton. go here http://www.thunderracing.com/catalog...vid=3&pcid=107

I used to run comp lifters but had them come apart on me, now I am just running brand new stockers to 6800rpm with no trouble (thus far).. if the coin was there at the time I would've gone with morels. I don't think stock is a bad choice at all so long as the setup is right on.

as for the ses light can't help you, mine for some reason has four wires running to it.

Matt, sorry to hear about your lifter issue - you might also check out the GMPP "Caddy lifters" (CTS-V endurance racing), I've heard a number of good things about 'em. (As a matter of fact, I bought a set when I thought that I'd be throwing L92 heads onto a "normal" 6L pullout engine...)

five7 - I started to reply regarding the fuel pump, then remembered that we're each using a different setup, so my response wouldn't have been especially useful.

Yes, as usual...

On the TPI cars, the fuel pump grounds where the wiring goes through the hump to the fuel pump. And that is the pressure switch for the A/C, there's only one on the 4th gen cars which is both low and high switch.

The carb car fuel level wires go back to the rear corner by the tail light for the pass-through. Sounds like the EFI cars have a different bulkhead location.
Curious that it has 3 terminals. Now, is the connector for it part of the engine harness, or part of the chassis harness? I'm going to have custom AC lines made, so I imagine they could put that switch in instead of the low pressure switch that the '82 had. I didn't get the line it goes into, just the ones coming off the compressor.

it's part of the engine harness

Then I'll have to look some more.

Mines grounded under the back seat at the same spot the fuel sender grounds. Theres a nice screw and knurly washer there you'll see it when you get the carpet out of the way. That sensor in the pic is the high pressure safety from the AC high side line on the stock LS1 set up. I just plugged the sensor in and let it dangle somewhere down in the breeze behind the HVAC box. Its there to shut off the compressor if the pressure gets too high but not needed to make it function.


mw66nova dont worry about it just run it. Mine ticks so loud I thought it was trash at first too its the lifter pre load that does it. You can add longer pushrods and that quiets it down tremendously but its not safe. I followed this advice by my tuner who has had 7-9 second LS1's so I trusted him. Its annoying as heck to hear it all the time but its been two seasons like that at 7K RPM many many times without issue so I guess he was right. Its one of the major downsides to these engines is the valvetrain noise. Piston slap is also a major pita my truck sounds like it has a blown rod at start up everyday but 300K + miles and still running strong. Doesn't even use oil nor does it turn black.

There's a ground lug on the rear panel below the hatch for the tail light and hatch release. I already have that panel off, it's nice & handy, might as well use that one.

Lifter & piston slap - aluminum and plastic don't insulate sound as well as cast iron does.

Okay, found the AC pressure switch connector. Helps when you have some idea where to look for it. . .

i dont have an ls1 car,(yet), so i'm not certain, but i'd bet that the ses light on the donor car wasn't an led, probably a small incandescent. might check on that.

All of the lights except the dash lights that come on with the headlights are all LEDs, the wire should only be one wire coming from the PCM to the SES. The cluster is grounded to the chassis as well. However, the cluster has 12v going to it and the LED is part of the cluster, there is no power coming across the PCM wire going to the SES light, it gets it's power from the gauge cluster.

I measured the pump resistance where the 4th gen wires were cut, 5.8 ohms. I ran a new power wire up to the engine bay through the passenger compartment, and ground wire up to that lug by the hatch latch. I used insulated disconnects by the tank to make removal easier if necessary in the future. Measured the resistance from the wire to the brake booster, 5.8 ohms. So, I think I have a good circuit there.

Got the rear sway bar installed, getting close to being done under the car. But, now I need to head to Nebraska because my mom isn't doing well. So, I probably won't get back to the car this week, and maybe not again this month.

Just chimin in... I agree with the ground for the fuel pump being under the rear seat...but anywhere you can get a good chassis ground will work perfect. Ide put it inside...just to keep it weather safe.

You already figured the switch out...

The MIL should have power all the time. The PCM grounds the light when it has to come on. I had issues using an LED for my MIL. It would sort of come on all the time...just really dim. I switched to low wattage regular bulb. Also...be aware that not every DTC will trigger the light. Some of them will show up during a scan, but wont set the light. If you use HPTuners...you will see that for each "code", you can flag it to do different things. "Set DTC", "Set MIL", "No action" etc etc. Does the light come on during start up as it should for "self check" of the bulb?

J.

no it doesn't, i grounded the one side of the wire, gotta run it to a switched power source i guess, lol!

ghettocrusier is correct, the ls1 pcm controls the circuit grounds, not the(+) power.

The LS7 lifters were recommended to me, so I bought them. Apparently a lot of LS guys buy the LS7 lifters as an affordable upgrade from the stock LS1 lifters. They were cheap ($119 at Texas Speed).

Ide like to replace my lifters, push rods, and rockers...but Ive been putting it off. I have a ticking as well...but I describe it more as the "sewing machine" sound that many others hear from these motors. Plus with the stainless headers, sound transmits easier. My other thought is...I have a bent push rod. Ive yet to actually check them for fear of screwing something...and because Im lazy about that sort of thing. Maybe this weekend if I get everything else done Ill check them.

J.

I wouldn't be too lazy about swapping out the bent push rod. Read the stickies and use the EOIC method for adjusting your rockers. To swap just the push rod out and adjust you are talking about a 2 hour job.

there is no EOIC method to an lsx engine. set the suckers to 22ftlbs and your done. doesn't even matter if they're at #1tdc...these things are cool as crap! the valve train is non-adjustable so you just torque to spec and rock and roll

Well the lazy part came from me thinking you had to have both valves closed before torquing them to 22ftlbs... And bumping the motor 100 times to get it that way made me lazy. haha. In order to crank my motor, I have to hold a reed switch in a spot on my dash...which makes bumping with the key a pain. But I can get around it I guess.

Im not sure I have a bent rod...but Im going to check this weekend I think. Im actually hoping thats all it is. I do have hardened rods, and I have missed a shift when I first started driving. So we'll see. Ill stop hijacking now

J.

EDIT: Ordered a length checker. I sort of doubt I have a bent one...but Im questioning the length since I have milled heads. Depending on the base circle of my cam, I might need to order different ones.

Next time, I need to pay attention to the engine he was talking about... Gotta pay attention... LOL But, I still wouldn't be driving around with a bent pushrod.

both valves do not have to be closed, just torque 'em. they'll open the valve before you get to 22ft lbs.

Yeah, you're right there - but this isn't his DD, & based on all of his posts I've read, I'm pretty confident (errrr, hoping??) that he will be addressing that before he puts any more miles on the car...

Dont worry I highly doubt I have a bent rod. Ill be checking it all over before this driving season starts.

Besides...you guys know if I blow it up it'll just be another build thread to read haha. Next motor that will go in that car wont be 346 ci...or NA

J.

57 - even when you ask a question i learn from you. i had no idea that the 98 ls1 went back to maf. you learn something every darn day.
are you working on a 6L?
what is it going in?

The LT1 went back to MAF in '94, I believe it was.

I'm putting a standard 5.7 LS1 in Berlinetta #2. I'm toying with the idea of a 6.0 or 6.2 for the '57.