Spark plugs fire after cranking

[ninjai_ruken]

Well guys, I'm fighting a no start issue with the flying banana right now. And Drivability and Diagnostics is not my strong suit. Right now I am not getting spark while the motor is cranking. Once I let off the push button I get spark on cylinder 1-4 (waste spark) anyone have any ideas? I replaced the CAS with a new unit a couple of weeks ago and mechanical timing is good.

Ty McBride
Team Leader/Owner
McBride Motorsports

Sent from HTC One M8

 

[brads]

Have you checked voltage during cranking?

 

[ninjai_ruken]

Have you checked voltage during cranking?

Yes, or at least to be more specific I tried and was sure I got a reading. The reason I said tried is I am by myself on this project and my leads for my fluke are not that long. I ohm checked primary and secondary coils and they're good. Since the system is NPN I was thinking ground maybe? Thank you

Ty McBride
Team Leader/Owner
McBride Motorsports

 

[brads]

Grounding problems can definitely do it.

I suggested checking voltage during cranking because with a weak battery, that can drop too low to run when the starter is engaged. Then when you stop cranking system voltage spikes up as the starter disengages, and make it sound like it is wanting to start.

Have you tried checking the plugs to see if you get a spark during cranking?

 

[ninjai_ruken]

Grounding problems can definitely do it.

I suggested checking voltage during cranking because with a weak battery, that can drop too low to run when the starter is engaged. Then when you stop cranking system voltage spikes up as the starter disengages, and make it sound like it is wanting to start.

Have you tried checking the plugs to see if you get a spark during cranking?

I did check for spark during cranking, that's how I discovered the issue. I thought I had no spark at all which I didnt at first. Replaced the CAS after it tested bad. Still no start up, pulled the COP bracket grounded out the plugs and bam, they're firing as soon as I let off the starter button. This weekend I'm going to go through and inspect, clean and reground everything. I checked my CAS twice to ensure it was in time with Cylinder 1 TDC. I will also try a fresh battery. I had the battery on a charger but I temporarily put a cheap Wal Mart battery in it.I'll keep you upalsod on the outcome. It sucks because opening races are this weekend. I'm still shooting for Sand Hills open road challenge in Aug if she's running strong. It's amazing how much cold storage can mess a vehicle up.

Ty McBride
Team Leader/Owner
McBride Motorsports

 

[ninjai_ruken]

Ok guys, got the issue figured out and repaired, It was a Bad EPROM and US COMs Circuit. They also updated my Coil and Cam/Crank Mods. Now I have a new issue, Car idles like crud and it will shut off. I dont mean stall out and die. It will shut completely off. I can get on the throttle a little bit and it will smooth out and then just shut off. Nothing looks abnormal on the lap top so Im a bit stumped. I checked Timing, CAS, I have Spark and Fuel...Needless to say this season is starting to look like a bust. Anyone has any input Im willing to listen. Thank you

Ty McBride
Team Leader/Owner
McBride Motorsports

 

[nwBryce89]

Does everything shut down including all electrics or just engine?

 

[ninjai_ruken]

Does everything shut down including all electrics or just engine?

Just the motor, it's weird. It's not like it stalls out. It just shuts completely off. I'm working and can't diagnose her fully eight now. But man I was really hoping to throw the ECU in her and be ready to rock.

Ty McBride
Team leader/Owner
McBride Motorsports

 

[Ferp]

I know this is probably not the case but are your battery connections snug? A shop didn't tighten my negative terminal one time and the car died similar to how yours is. I popped the hood and I saw the cable was quite loose, I'm assuming it would lift up with the torque from the motor just enough to terminate the connection then fall back on.

 

[ninjai_ruken]

I know this is probably not the case but are your battery connections snug? A shop didn't tighten my negative terminal one time and the car died similar to how yours is. I popped the hood and I saw the cable was quite loose, I'm assuming it would lift up with the torque from the motor just enough to terminate the connection then fall back on.

Battery is good and connections secure. A little up date. So I haven't had much time to look at her as of late. But I did get out under the hood today. All connections are good and secure. All grounds were clean and I conducted some voltage drops and everything looked good. What I think is happening is the car is getting way too much fuel. I pulled the plugs and they all smelled like gas and looked wet they looked clean though no fouling but the car doesn't run long enough for them to foul any ways. . If I have the fuel pump on it'll act like it wants to start for a few cranks but then will just shit there and crank. If I turn the pump off and press the throttle while cranking she will fire up, run like ass and then cut out after 4-8 seconds if I turn the pump on after she starts it might run 2-3 seconds longer but still cuts out. I have good fuel pressure but I am going to check out my fuel injectors tomorrow and make sure none are stuck open, also going to check my fuel return line and a few other things....Car has been a P-A-I-N in my A-S-S as of late.

Ty McBride
Team Leader/Owner
McBride Motorsports

 

[brads]

Have you checked the ECT reading? TPS?

 

[ninjai_ruken]

Have you checked the ECT reading? TPS?

Have not got around to checking the TP Sensor yet, but the ECT gave me a good reading. I just replaced it a couple of months ago. I need to make a list, and just start going through things one at a time. Its almost as if shes flooding out, Im all the fuel injectors check out ok as far but I still have not checked them to see if any are stuck open. My dang plate is so full right now im having a hard time finding time to get under the hood and its actually stressing me out. Ill keep you guys updated on the progress!

Ty McBride
Team Leader/Owner
McBride Motorsports