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Discussion Starter · #1 ·
I got to thinking about this non-starting problem.
I think i told you this before,that i have nitrous
wired up to this car.I noticed that the time the car fails to start is when i purge the nitrous a bunch before starting the car.I also told you the cables get hot but this Sat at the track i noticed the msd box felt hot.The nitrous works fine when purging it before i pull into the staging lane then it does not work.What Im leading up to is this!The main hot wire is hooked up to the tru-cable along with the msd hot lead.
The nitrous hot runs to a relay.Could this be causing me the problem?This thru cable is the large battery cable running from the battery.On this large cable i have the nitrous with the relay
msd,hot for the purge and a couple more switches.
The nitrous hasn't worked in weeks and i have rewired it many times.I just got to thinking about the nitrous with the relay and msd and why the box is hot.What do you think?
 

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“The main hot wire is hooked up to the tru-cable along with the msd hot lead. The nitrous hot runs to a relay.Could this be causing me the problem?This thru cable is the large battery cable running from the battery.On this large cable i have the nitrous with the relay.”

I thought you had a cable from the trunk, to the starter, then to everything else. You have 2 large cables running back to the battery?
 

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Discussion Starter · #4 ·
I have the large cable running from the battery to the the through panel connector which goes tru the firewall and has a stud on both ends.Inside/outside.On the outside i have a cable running to the starter/on the inside i have the msd,nitrous,purge,deluxe fuse block 8 circuits for elec fans,elec water pump.
 

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Cable set-up sounds ok. A couple of thoughts. I am not a MSD expert but I heard that the MSD box does run warm to hot when it is operating. You may ask around. If you suspect that the purge relay is not operating or hanging up, tie a 12 volt LED on the relay contact. Other side of the LED goes to ground. The LED won’t affect the relay operation. Run the LED back up inside the car. Sort of a “purge on” light. This will tell you if the relay is opening and closing when it’s supposed to.
Not sure what to say about the starter. Perhaps maybe change it to one of the newer GM mini-starters. Should start better with one of these and that long cable should run cooler.
 

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Discussion Starter · #6 ·
Thanks John.Though maybe there is just to much hooked up at one point.The purge don't have a relay but the nitrous system does and thought maybe the relay from the nitrous was or could be causing the problem.Im going to try another hot place for the nitrous and see if that makes any changes.The job of a relay is to keep the volts at 12 or what ever it calls for?Question)What if i did a direct hook up with-out the relay?Would this be a problem?
 

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I'd leave the relay in. Not sure if moving things around are going to help things much. If I recall you have tried several things. Like I said, maybe give a later year GM mini-starter a shot. That should draw less current and keep the wire cooler. Others have said they start better. At least you will knock a couple of pounds off the front.
 

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Discussion Starter · #8 ·
I forgot to mention I already have one on the car. The car has been starting fine in the past week and a half. When it starts acting up is when I try to get the nitrous to work. I'll make a pass down the track but the nitrous fails to work. I'll come back and manually purge the nitrous by engaging the throttle switch that activates the nitrous. IT WORKS FINE.Do that a few times manually that's when the car fails to start. Notice battery cables are hot. If I don't mess with the nitrous I don't have a starting problem. Took me a while to figure out that playing with the nitrous was causing the car not to start. Can a relay go bad and cause these plobems? I know for sure it has something to do with this nitrous.
 

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Oh,,OK, I lose track of who has what. I don't have an instant answer but I toss out something.
How hard would it be to string in another line for the nitrous back to the cutoff switch? Doesn't need to be a huge gage. Something with an in-line fuse in it for safety. They sell them to hold the newer blade fuses.
Probably close to your orginal thought of moving the nitrous connection. By bringing in another positive line, power moves off the original cable and on to the add-on line. If it was the nitrous heating the original cable, the original cable would now be cool.
Sorry, I don't know what nitrous & purge systems normally draw to operate. Just trying to figure out which one of the items is the culprit making the cable hot.
 

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Maybe one more thing while you are under there. Hang another wire off solenoid "S" and bring it up and cap it off. The next time, if it happens again, use the wire with a remote switch to see if the starter turns. Trying to cover all bases.
Between the 2 changes maybe something will be learned.
 

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Discussion Starter · #12 ·
I got it ran but wasn't that simple.Wanted to run the wire thru the inside of the car but because of the roll cage i couldn't get the back seat to give any at all.Ended up running it out thu the firewall and down along the frame rail putting the
wire thru vacuum hoses to keep it from rubbing against the frame causing even more problems.Really won't know if this will help or not untill i run it down the track again.Good ideal on the wire off the s post.I read somewhere that the nitrous pulled 4-8 amps and the bigger ones up to 12.I think thats what i read but not 100% sure on that.This car has sure been a challenge over the past two years.On the positive side i sure have learned a lot.Anyway,thanks for all your help.bill
 

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Discussion Starter · #13 ·
Found something interesting this morning.Turned on the reg fuel(for motor) and turned on one thing at a time,tried the nitrous and didn't notice the fuel pump pull down but turn on the bottle heater and the fuel pump was really working hard.Bottle heater to keep the nitrous psi
at around a 1000 psi.All these other things running at the same time when going down the track could be very well my problem.Going down the track with two fuel pumps running,electric water pump,dual electric fans and nitrous trying to work at the same time may be to much.Thats why when Im sitting still and I keep testing the nitrous it seems to be working fine but go down the track the nitrous won't work.Question is how do I correct this problem?Run a 2nd battery and recharge it after every pass or is there another way?Im not good at adding amps but Im sure it's pulling a bunch.Two fuel pumps,dual fans,electric water pump,nitrous,bottle heater,line lock and purge and thats not counting if it's dark at the track when you have to run your tail lights.Also the msd .I could put relays on the fuel pumps but not sure that would help that much?So thats way the nitrous won't work by the time I turn everthing on theres not enough amps or volts to open up the nitrous solenoid.I went back out looking and noticed the electric fans don't have relays,I have none on the fuel pumps but the nitrous does and the bottle heater does.Will installing relays on the fuel pumps and fans help this problem?
 

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Discussion Starter · #14 ·
Did a little reading,nitrous solenoid pulls around 4 amps,fuel solenoid 1.5 amps.Fuel pumps around 3-4 each ,two fans i don't know,bottle heater i don't know but the way it pulls the fuel pump down i would say it pulls a lot.
 

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Discussion Starter · #15 ·
WELL WELL,This car has got me really confused.Went out to start it would not start(low battery).Put the battery charger on it(fired right up)This morning i was playing around to make sure the nitrous was working after doing the wire change and had the bottle heater on a couple
of times but not long enough to run the battery down.Anyway i put the volt meter on the main cable coming from the battery and turned on everthing and hit the nitrous and the volt meter never went down at all.Started out at 14 volts and stayed at 14 volts.Shut the car off and it started right back up.I really don't know where to go with this car anymore.Everthing on it is brand new and most are brand new twice.
 

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Discussion Starter · #16 ·
Maybe I'll leave it sit untill this winter and then gut all the wires and buy a painless for a pro street or something.I have done eveything in the world to this car with no luck.I thought i was on to something this morning with the relays but i guess not.I have always said this car has had a miss around 3,000 rpms which i still think it's got something to do with this whole electrical system.Got me? :confused:
 

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Helps if you stick to one thing at a time. It does get a little confusing trying to look at everything. Stay with your original problem of "Battery cable gets real hot and starter won't start".

First thing we tried was moving the nitrous off the main battery cable. Results from that are either:
1, Main cable now is cool, but little cable pops fuse.
2, Nothing has changed.

Adding the bump wire on to solenoid "S" terminal can show:
1, Car doesn't spin starter with key switch but will with the remote switch. Problem is with the key switch wiring.
2, Car doesn't spin starter with either the key switch or the remote switch. Problem is with the battery or starter.
 

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The one comment I have about the wiring you describe is that I believe you have a 1awg wire running to the firewall connector. If that wire can't power all your accessories then you either have an accessory problem or a bad connection in that wiring.

As for the voltage, the system holds 14V while everything is on including the bottle heater? This contradicts what you say about the pump laboring when you turn on the bottle heater.

If I were you, I would first disconnect all of the nitrous wiring including the bottle heater and see if you problems go away.

Every time you describe your electrical system properties that bottle heater seems to be causing excessive current draw and voltage drop.

At any rate, during a run you should have the bottle heater and the fans turned off.

Feel like a 7 or 8 hour drive some weekend? Maybe you could convince me to look at it ;)

Peter
 

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Discussion Starter · #19 ·
It's tough for sure.I do turn off the bottle heater when doing a run but leave the fans on.It has pretty much kicked my butt I just posted it for sale on racing junk.com.
 

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Don't give up on the car yet.

I'd almost bet that you are overloading your alternator. If you've gone through all the wiring connections multiple times then it's probably the alternator. I believe you have a 70 or 80 amp alternator and for all the stuff you list I still don't think it is enough. Your alternator has to produce the current your loads require at idle and the 70A rating (any alternator current rating) is at about 1500rpm or more(which is 2500 alternator rpm's).For big loads you need a big altnerator, there's just no way around this. That's why I suggest disconnection all the nitrous stuff because if it begins working without that load you will know you're overloading it.

And I am serious about you coming up to visit if you want


Peter
 
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