Help!! Engine won't start??

[Bigmil]

So I raced last Saturday and the only thing that happened was that it took an extra long time to get the car started (had to keep cranking) for the first practice.  After that it started fine all night long and ran great (accept for my novice driving).
Then
I go out today to get the car ready for this weekends race and it won't start.  It turns over but won't fire.  It barely stumbles everylittle bit...but just barely....almost to where I wouldn't mention it....but I did.
I took out each spark plug and verified that the was sparking (didn't look strong but I don't exactly know what strong looked like).  I did note that there was no fuel on the spark plugs like I thought there would be if the engine was flooded.  So I also took the fuel line off the carb and turn the ignition on and verified that fuel shoots out.  I put the fule line back and it still won't fire??
I have tried messing with the choke (but it's like 90 degrees today and didn't think it would need it anyway) which is where the slight stumbling came in,  But still nothing.

I am completely lost.  Could I be not getting enough spark?  How would you check and what would cause that?  And if that was true wouldn't the plugs have unburnt fuel on them?  Is there something in the carb assembly that can get plugged up?


Aghhhh.......Please help I want to go racing this weekend!!

Gerad

[VMS Motorsports]

Check the ground wire to the starter

[justfreaky]

Hi Gerad,

a) Fouled plugs
b) Contaminated fuel
c) Improperly adjusted carbs
d) Weak ignition coils
e) Weak pulse generator(s)
f) Weak spark unit(s)
g) Poor compression
h) vacuum leak

As Jim suggested, Check for tight wiring connections, check plug wires (good connection? cracked? etc...)
Have you tried a shot of starting fluid? Will usually get anything to fire up, if only briefly.

Throwing out some general stuff to check.

Steve

[Bigmil]

I checked the ground wire to the strater and it was secure.  I even tried wiggling it while trying to start it.  Still notta.

a) The plugs don't appear to be fouled but I will change them tommorow.......What plugs should be in there (I have a 1200 open)?

b) The fuel is new but I guess it still could be bad (just topped off the tank tonight but already had atleast half a tank of what I raced with in it)?

c) The carbs were fine last Saturday and I don't touchem

d) Is there a way to test the ignition coils?
e) Can you test the pulse generator (I don't even know what this is?)
f) Again I don't know what the spark unit is or how to test it?
g) I check and have decent compression
h) From what I can tell there is only one vaccum line and that us from the carb to the electronic control module thingy on the firewall.  I check that line and didn't find anything obvious.


I think I am going to get new spark plugs tommorow (assuming I know which ones to get) and go from there.  I will also get some starting fluid and try that out.  That should tell me if it is a fuel or spark issue for sure.

Thank you, keep it coming.
Gerad

[justfreaky]

Gerad,

Here is a thread to spark plugs.
http://www.legendsracer.com/index.php?topic=101.0

What did your plugs look like? Black, White, Tan?
When you checked for spark, did you get a fat blue spark or was it weak looking?
Have you sprayed some carb cleaner to clean air passages in carbs? Sometimes, just sitting for a week will gum them up.
Doubtful that it is too serious. Check all electrical connections. Sometimes it's just silly stuff that comes loose.

To test coils:

1) Disconnect the primary leads from the coil. Use an ohm meter set at Rx10 and measure between the 2 primary wires. Resistance should be around 2.8 ohms.
2) Remove the secondary leads (spark plug wires) from the coils
3) Use an ohm meter set at Rx1000 and measure between the  secondary lead receptical in the coil and the mounting bolts. The resistance should be about 21,000 - 28,000 ohms.
4) If the coils fail to pass any of these tests the coil should be replaced.
5)Use an ohm meter and check for continuity through the spark plug wires and cap. There should be continuity (high resistance). If there is no continuity, the spark plug lead or cap is faulty.

This info is out of one of my motorcycle manuals. Can send more info if needed.

Steve

[VMS Motorsports]

I still think its a loose ground wire. Have had that issue more than once.
Sounds stupid, but charge/test the battery, if the battery is weak, the starter sucks most of the juice to turn it over, and there wont be enough to fire it

[thunder938]

Do you have a red box or black? IF red try to get one off a buddies car and plug it in and see if that changes it.  I had a box go bad and it would be hard to start then run on on 2,..then clear and run on 4???put a new box and fixed it.

Mine went bad BETWEEN races over the week???  If you have a black box I dont know

[VMS Motorsports]

On the ground wire thing, when checking the battery, make sure you have a good ground back there too.

[Bigmil]

You guys are fantastic!!

As soon as I get home from work I will be checking those coils out.

I have a black box...haven't been able to afford an upgrade yet......and if it is that I don't think I will be racing this weekend as I don't have a supplier near by that I can pick one up from.  This makes me nervous.....

I had the car on a charger all last night while trying to start it, so I think that is fine (and I left it on a trickle charger over night so this afternoon when I check it next it should be the best it can be).  Plus the starter turns over real good.  I think I will take off the starter ground and clean up the surfaces and reinstall it.  Maybe that's the issue.  I will check the battery grounds as well.  Are there any other significant grounds that I should check?

On the spark plugs, do you guys buy them online or is there a local store that carry's what ya'll use.  I checked Napa and Autozome and they don't carry any of what I am looking for.

Thanks guys I have a lot of work to do tonight!

Gerad

[VMS Motorsports]

I buy my spark plugs at Fleet & Farm, they're cheaper there than I can buy them from NGK! I don't use the fancy stuff though, just the regular old plugs-so they are always in stock.

4 plugs arent going to go bad just sitting for 6 days.

Just the 2 grounds unless others were added after 600 built the car.

I'd bet it's a loose connection somewhere, just need to find the time to find it.

[justfreaky]

Jim was telling me that the spark plug connectors (inside the spark plug wires) tighten down with a flat bladed screwdriver.
Perhaps could be causing weak spark. His were loose.

Steve

[Bigmil]

Ok, so now I am really confused

First I will say that I have the old school black box ignition (with the vacuum advance)
I checked the coil primary wire resistance on both coils....they both eventually settled at 2.5 ohms (not sure if that is close enough to the 2.8 ohms you spec'd
I then checked the coil secondary wire (spark plug wire) to the coil hold down bolt.  Now because I have the old black box I couldn't take off the spark plug wire from the coil (or atleast I didn't want to pull hard enough to find out) so I measured from the metal inside the boot to the hold down bolt and got nothing.  Like they weren't even connected.  But the more I think about that it makes sense because the combined resistance of the coil and the plug wire should be high (because of the high current that needs to pass through).  So I didn't learn much here.

I replaced all four spark plugs with slightly used ones out of an old engine I blew up 2 months ago (couldn't find the replacment ones I wanted yet, need to order online).

I pulled off the starter ground and cleaned the frame connection and the connector to make sure there was a good connection.  Then I chesked the ground at the battery and everything was solid.

I also got some starting fluid and sprayed that in during the next step (to no avail)...

So after all this I tried firing it up and......nothing, still wouldn't start.  So I was getting a little pissed at the car at this point and just started cranking and slamming on the gas pedal (for like 10  minutes....it was a long tantrum) then .....to my surprise it started stumbling a little more.....then a little more....then vroom off she went .  Once started she ran like nothing was wrong.  Revved all the way up to 10k (to my neighbors amusment I'm sure) and no problems. 

So I have no clue what happened.  I eventually warmed the engine up and now I am letting it cool back down and I will try it again periodically throught the afternoon and tommorow to see if it has any more problems.

The only thing I can think of came after I read the "what fuel do you use" string in which someone said that sometimes higher octane gas at the pump can sit longer in the ground at the station and get problems.  I am wondering if this played into the matter?  I don't know but this weekend I am going to drive out of my way to try and get some CAM2 100 octane stuff to mix in with my sunoco 93 octane to see if that helps?  I may also get some octane boost from Autozone and add that.

This all seemed to start after I got gas from a different than the usual gas station?

Anyway I will let you guys know if it gets any better once I up the octane of this batch.  If it's not that I think I am going to start saving for a redbox and coil ignition system.

Thanks for all your help!!!

Gerad

[justfreaky]

Could have just had a little something gummed up in the carbs. Glad you got it started!!!
93 or 98 octane should work just fine. Not really much need to spend the extra for racing fuel. MHO.
You might want to drain your fuel cell between races, and run out what fuel is in the carbs.
Old fuel works great in the lawn mower. lol!!!

Best Of Luck!

Steve

[VMS Motorsports]

The repeated "Slamming" on the gas pedal could cause enough vacuum to build up to get it running...possible vac boost/carb issue?
Or maybe thats me, and Im sending you my problems!
Let us know how it goes this weekend

[justfreaky]

LOL!
Not entirely sure that Gerard and your problems are not inter-related. All that carb and ignition stuff gets kind of interwoven.

Steve