moochiemike123 Posted July 27, 2007 Share Posted July 27, 2007 So heres the deal: I just finished the fuel lines, and everything should be wired right. I did was was said by VinhZXT in http://forums.hybridz.org/showthread.php?t=119052&highlight=ls1+wiring+info EXCEPT for the tach, and the high/low fans. Also, the cooling system isn't finished yet, so there is no coolant in the engine. Does the computer know that these things aren't done, and thats why its not starting? If not that, then I'm lost as to what it could be. (I've checked, double checked, and triple checked the wiring) Any info would be appreciated! Quote Link to comment Share on other sites More sharing options...
EvilC Posted July 27, 2007 Share Posted July 27, 2007 I just had this problem a week ago! My problem was that the PCM was not getting a constant 12v during cranking. Did you check if you are getting fuel? Check if the injectors are pulsing. If they are then the problem I believ would be with the PCM not telling the motor to start. Also your PCM may still have the theft system on and that also will prevent the motor from starting. Others may have more to add. Hope this helps. Clive Quote Link to comment Share on other sites More sharing options...
moochiemike123 Posted July 27, 2007 Author Share Posted July 27, 2007 So how did you fix that? Was your battery bad? I tested my car, and the voltage drops to 8.5-9.5. It could be because the battery isn't charged all the way, considering it dropped from 11.5 Quote Link to comment Share on other sites More sharing options...
EvilC Posted July 27, 2007 Share Posted July 27, 2007 I just hot wired my PCM wire right to the battery for now just for startups but all I have to do is change the power wire to the right ignition 12v source and it will be fine. Vinh is coming out to finish my car for me next week. I am sure he will have some input here. Quote Link to comment Share on other sites More sharing options...
SSflyer Posted July 27, 2007 Share Posted July 27, 2007 Same problem when I did mine. #1 Check for 12v at PCM #2 Check for 12v at the injectors #3 If it cranks but won't start CHECK YOUR GROUNDS! Don't assume they're good, make sure they're good. There's multiple grounds from the PCM, several in the dash harness, and several from the underhood fuse box. Any single one of them could cause your problem. Ask me how I know. #4 Is your clutch/neutral safety switch wired and working #5 Are your ignition control relays good? Other more obtuse reasons could be a bad crankshaft position sensor, a bad cam position sensor, or even a bad air intake temp sensor. Good luck! Quote Link to comment Share on other sites More sharing options...
moochiemike123 Posted July 27, 2007 Author Share Posted July 27, 2007 SSflyer, as for: #3, You mentioned grounds in the dash wiring harness. I assume you mean the ls1 donor car's dash harness, right? I don't have that in yet, and I don't have the gauges in either (the only reason why I'm using it is to use the gauges). Do I need to have that in? and how do I identify which wires need to be grounded? #4, My clutch switch is just an interruption in the ground of the starter relay when the clutch is engaged. does the PCM need a signal to know when the clutch is engaged or not? If so, how? #5, I hope those ignition control relays are somewhere on the engine, or in the engine wiring harness, otherwise, I don't have them... donor car was an 02' trans am, and there were like 2 relays in the dash/body wiring harness... were those them? Thanks! Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted July 28, 2007 Share Posted July 28, 2007 Just to make sure you are not making the same mistake that I've made on Clive's car. Connect all the Orange and Pink wires directly to 12V and see it starts. Orange wires go to constant 12V and all the Pink wires go to Ignition #1 source which should have 12 in the RUN and while cranking. Check to make sure you have all the ground wires behind the passenger side's head bolt to the head and your ground cable goes from there to the negative side of the battery. Check to make sure your crank sensor connector is plug in all the way. Do you have some type of scanner? If you do you can use it to read the trouble codes off the PCM. If you have bad sensors or unconnected sensors it will tell you. On my swap I used the C5 instrument cluster and I can use it to scan trouble codes off the PCM. GL. Vinh Quote Link to comment Share on other sites More sharing options...
heavy85 Posted July 28, 2007 Share Posted July 28, 2007 Check to make sure your crank sensor connector is plug in all the way. Vinh Where is it on an LS1? Reason I ask is I have an extra connector and according to the pinout it goes to the CPS but I cant seem to find the sensor to plug it into? Thanks Cameron Quote Link to comment Share on other sites More sharing options...
moochiemike123 Posted July 28, 2007 Author Share Posted July 28, 2007 ok, so I found a thread where someone posted a diagnostic series of tests (taken from a RX7 board) and followed what it said. All grounds are good, the power is hooked up like you said, Vinh, sensors are plugged in (except there is one question I have: I believe the crank position sensor is plugged in (behind the starter) but there is a plug hanging from that area. It has 3 pins. There also seems to be a sensor in the oil pan (oil level?) which has 2 pins and has no plug for it. the wiring harness is for a manual, and the engine was with an auto tranny when we got it, so is it the wrong harness?) And as for the no starting, I did some more testing. I'm not getting my noid light to light up, so the injectors are not getting anything. this leads me to believe that there may be something wrong with the PCM. To further my belief with this, I hooked up the OBDII plug, and it doesn't seem to be getting any signal, it just tells me to turn the car into run, when it is... I want to test the PCM (which we got flashed to rid various things (VATS, 2 O@ sensors, limits, etc) in another car, but don't know anyone who has a compatible car (1999+ f-body, I believe). Is there a way I can test the PCM myself? I am very positive this is it... Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted July 28, 2007 Share Posted July 28, 2007 Cameron, The crank position sensor is right next to the starter. It's very hard to get to but with small hands you can get to it. Otherwise you have to remove the starter to get to it. If you don't have this sensor hook up you won't get any spark. Moochie, For a quick test just connect all your orange and pink wires directly to the battery and see you get sparks. On Clive's car I mistakenly connected the pink wires to ignition #2 source and we didn't get any sparks either. The oil level sensor is on the right side of the oil pan. There should be a hole on the side of the oil pan and there is where the sensor is. On my swap (98 C5 motor and PCM) I forgot the hook up the oil level sensor and I couldn't start the car. I am not sure this is the same for the Fbody cars. The C5 has many little options installed to protect the engine from getting damage and this is one of them. No oil no start. If you talk to John at Spear Tech he might have different opinion on this one but this is my own experience with my C5 swap. The PCM doesn't go bad by itself. The PCM doesn't care about the manual or auto car. What matter is what program do you have in the PCM. You should have the correct program for what trans you have. Again I haven't look into how the auto tranny and the PCM on the Fbody work but I know how the C5 auto trans and PCM work. The C5 PCM actually sends out signals to lock and unlock the converter depends on what condition the engine is in and what gears it's in. GL Vinh Quote Link to comment Share on other sites More sharing options...
moochiemike123 Posted July 29, 2007 Author Share Posted July 29, 2007 Ok, heres an update on the problem. We went pin for pin on the PCM, just to make sure everything was hooked up right. We found that the wire we hooked up as the PCM serial for the OBDII plug was wrong, so we fixed that. We were able to communicate with the PCM now, so we know that its all good. It did throw a code: P0452: Fuel Tank Pressure Sensor Circuit Low Voltage. With some research, I found that this is nothing to prevent the car from starting, so it has been ignored for now... We (temporarily) grounded the PCM's clutch signal switch, so it should know that we have the clutch in. We checked all powers, grounds and plugs like 5 times, ant its all good except the oil level sensor, which is kinda ghetto wired. We checked voltage at the injectors. We are getting a constant 5.7v with the ignition on "ON" and drops down to 4ish during cranking. And still no spark either. (plugs look fine; not fouled) Just in case the PCM is the problem, we are gonna take it to a dealer to get it checked out. (we don't know anyone with an f-body). Any ideas of what can be wrong now? I've tested just about everything, and still no luck... D: Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted July 30, 2007 Share Posted July 30, 2007 Sounds like your ignition #1 source is weak. You're suppose to get 12V to all the pink wires ( injectors and other sensors). There is a very simple way to check. Connect all Pink and Orange wires from the harness directly to the battery and try to start it. I know this can be very frustrating but if you keep everything simple it will help you find the problem easier. GL Quote Link to comment Share on other sites More sharing options...
EvilC Posted July 30, 2007 Share Posted July 30, 2007 I think Vinh is right. I do not think your PCM is bad and your 12v signal is very weak. Just try as stated to "hot wire" everything right to the battery. You should get the engine to start that way. Took me, Vinh, and John at Speartech to figure this out. Which LS1 motor do you have? I do not have my oil pressure sending unit hooked up and it starts...hope that helps. Clive Quote Link to comment Share on other sites More sharing options...
moochiemike123 Posted July 30, 2007 Author Share Posted July 30, 2007 Ok, turns out I had the crank position sensor switched with the oil level sensor plug... D: I feel stupid, but happy it starts up now! But for the cooling system now: I'm not using a heater. Should I bridge the heater hoses, or plug them individually? And if plug them individually, whats the best way to go about doing this? Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted July 30, 2007 Share Posted July 30, 2007 "I had the crank position sensor switched with the oil level sensor plug" You must be joking right? The crank position sensor plug has 3 wires and the oil level switch has 2 wires. Even if you wanted to you can't plug one into the other. Quote Link to comment Share on other sites More sharing options...
EvilC Posted July 30, 2007 Share Posted July 30, 2007 I do not have a pic of mine but I just used a U shaped hose and connect the two lines coming off the motor. That is the easiest way to go. Glad to hear that it runs!!!!....pics??vids?? Quote Link to comment Share on other sites More sharing options...
moochiemike123 Posted July 30, 2007 Author Share Posted July 30, 2007 yeah, I don't get it either, Vinh, but the 2-pin oil level plug clipped into the 3-pin crank position sensor... and I'll post a vid of it running later (its too early now, it'll wake the neighbors Quote Link to comment Share on other sites More sharing options...
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