Few lil problems with first run
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Teching In
Joined: Apr 2007
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Few lil problems with first run So I took my 240z with our favorite LS-1 (out of a 02 trans am) for its first test run. it was working great, except for just a few problems.
1. Engine stops at about 3500rpm when I floor it, and fuel pump makes strange noises. Solution: add more gas. Hey, I figured that one out myself!
2. Speedometer dosent work. All other gauges do. IIRC, the speedo runs off of the VSS wire. I have that hooked up to the gauges with the right wire. When I was wiring it all, there was a wire that I labeled speedo, and one VSS (both grn/wht, I believe) so I went with the VSS one. Might it be the other?
3. The fans arent turning on. I have them wired to the PCM (both high and low speeds). I know both speeds work, because I can apply power directly to the wire, and it closes the relays and turns them on. Maybe the PCM isnt sending the signal? or is it a different kind of signal?
Other than that, it runs great!
1. Engine stops at about 3500rpm when I floor it, and fuel pump makes strange noises. Solution: add more gas. Hey, I figured that one out myself!
2. Speedometer dosent work. All other gauges do. IIRC, the speedo runs off of the VSS wire. I have that hooked up to the gauges with the right wire. When I was wiring it all, there was a wire that I labeled speedo, and one VSS (both grn/wht, I believe) so I went with the VSS one. Might it be the other?
3. The fans arent turning on. I have them wired to the PCM (both high and low speeds). I know both speeds work, because I can apply power directly to the wire, and it closes the relays and turns them on. Maybe the PCM isnt sending the signal? or is it a different kind of signal?
Other than that, it runs great!
OK, do NOT take this as gospel, since I'm still at the bottom of the learning curve, but I seem to recall from another discussion that the output for the fan relays is different from all of the other outputs (ie, everything's grounded, but the fans get power, or vice-versa) .
Can anyone confirm that?
Can anyone confirm that?
Joined: Sep 2004
Posts: 3,148
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From: Downers Grove, IL
Oh yeah there were more questions there 
I gotta start getting more sleep.
1. Yeah I did the same thing, the LSx`s sure pull good
2. What type of signal does your speedometer want? Sine wave AC or square wave DC? also did you try to calibrate it?
3. /\ yep got that one in the last post
I gotta start getting more sleep.1. Yeah I did the same thing, the LSx`s sure pull good
2. What type of signal does your speedometer want? Sine wave AC or square wave DC? also did you try to calibrate it?
3. /\ yep got that one in the last post
Thread Starter
Teching In
Joined: Apr 2007
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Ok, so I'll just put 12v at what I currently have as the grounds for the relays.
As for the gauges, I am using the stock gauge cluster from the same trans am that the engine came from, so I'm pretty sure they're compatible.
As for the gauges, I am using the stock gauge cluster from the same trans am that the engine came from, so I'm pretty sure they're compatible.
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Joined: Sep 2004
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From: Downers Grove, IL
If you are running a factory cluster/speedo you need to hook to the wire that is speedo connector 220 pin K/ red pcm connector pin 50 green and white.
If you hook it directly to the VSS output (grn/blk) the speedo will not work.
If you hook it directly to the VSS output (grn/blk) the speedo will not work.
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Verdad Gallardo Thread Starter
Teching In
Joined: Apr 2007
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so connect the grn/wht wire that is pin 50 red to which gauge cluster wire? the links below are diagrams that I used to wire the gauges up.
https://ls1tech.com/forums/attachment...chmentid=53705
https://ls1tech.com/forums/attachment...chmentid=53706
right now I have the VSS signal hooked to pin B8. If thats where the pin 50 red wire goes, then where does the VSS go to?
https://ls1tech.com/forums/attachment...chmentid=53705
https://ls1tech.com/forums/attachment...chmentid=53706
right now I have the VSS signal hooked to pin B8. If thats where the pin 50 red wire goes, then where does the VSS go to?
Thread Starter
Teching In
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Alright, so I went out and checked, and it turns out that the wire that I had labeled "speedo" was pin 50 red. I hooked that up to B8 on the cluster wires.
I couldnt test it out, because I still need to get some gas in it, and my car is in the shop.
What I did do, is put the ignition on "ON", and compare any difference between the two wires (you know how the needles move a little when you turn the car on) and neither wire caused the speedo needle to move. Is it supposed to move a little like the rest?
I couldnt test it out, because I still need to get some gas in it, and my car is in the shop.
What I did do, is put the ignition on "ON", and compare any difference between the two wires (you know how the needles move a little when you turn the car on) and neither wire caused the speedo needle to move. Is it supposed to move a little like the rest?
Thread Starter
Teching In
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ok, so the speedo works now. thanks for the help. now i have just one more question. I started on getting the fuel gauge to work (i have a fuel cell with a 0-90 ohm sender) and cant get it to work. I know the purple red 54 wire goes to one of the sender terminals, but where does the other go? is there a wiring diagram out there for this? ive been searching for so long, and just cant seem to find anything.
Joined: Sep 2004
Posts: 3,148
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From: Downers Grove, IL
I am attaching a diagram, but I don`t know if its possible to make a factory 2002 gauge work with a 0-90 ohm sender.
The factory 2002 sender is 280-40 ohms or something weird like that, not only is it a different resistance range, but the resistance is also in the opposite direction from the standard GM shifter.
The factory 2002 sender is 280-40 ohms or something weird like that, not only is it a different resistance range, but the resistance is also in the opposite direction from the standard GM shifter.
Thread Starter
Teching In
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oh, thats not good. I guess I heard somewhere that it was 0-90, possibly from Autometer. Thats what they're fuel gauges' ranges are. Maybe I was looking at a different year...
But even so, I was playing around with it, using 70, and then 150 (I heard of the 280-40 thing before) ohms of resistance, and couldnt get anything to happen. And I don't see an attachment. Did you forget to attach it?
But even so, I was playing around with it, using 70, and then 150 (I heard of the 280-40 thing before) ohms of resistance, and couldnt get anything to happen. And I don't see an attachment. Did you forget to attach it?