ignition issues on new motor

sk8world · 09-21-2008, 01:25 AM

I thought I would post here as well. I am trying to get my new motor dialed in before any tuning can really begin. Car starts, idles, drives (with med. knock numbers). Idle shows single digit knock, rev it and I see teens to 20's. drive it with low loads and I see high knock (60's-100's). Under very low load maybe 1-4psi knock goes down but ignition break up (detination ?) is present.

History, no issues with ignition on last motor. Changes made were rewiring crank angle sensors, knock sensor, injectors (added a FJO controller and removed resistors) blocked of OMP, rewired throttle sensor. Added a differant dual fuel pump setup, replaced water temp sensor.

I have check chaned igniter, coils, plugs, crank angle senor, checked wiring to injectors. Check wiring going into coils..

I guess I need to put a timing light on it next. I would also like to add an fuel pressure guage inside to verify fuel presure is not droping. Can not imagine why it would.

Any thoughts??

cewrx7r1 · 09-21-2008, 09:47 AM

Knock (really noise in this case) may be caused by engine/drivetrain parts hitting other parts or chassis. Shake the crap out of your engine and exhaust and listen for clanking.

Ignition problem is most likely due to some of your rewiring.

sk8world · 09-21-2008, 09:35 PM

Chuck, Good point, I also added a 4 inch exhaust system. Maybe it touching a bit. I found a issue on the rewiring in the TB sensor.. Damn your good Chuck! Now give me 6 numbers below 50!

09-21-2008, 01:25 AM	#1
sk8world 600rwhp club member. Join Date: Mar 2008 Posts: 551 Rep Power: 18	ignition issues on new motor I thought I would post here as well. I am trying to get my new motor dialed in before any tuning can really begin. Car starts, idles, drives (with med. knock numbers). Idle shows single digit knock, rev it and I see teens to 20's. drive it with low loads and I see high knock (60's-100's). Under very low load maybe 1-4psi knock goes down but ignition break up (detination ?) is present. History, no issues with ignition on last motor. Changes made were rewiring crank angle sensors, knock sensor, injectors (added a FJO controller and removed resistors) blocked of OMP, rewired throttle sensor. Added a differant dual fuel pump setup, replaced water temp sensor. I have check chaned igniter, coils, plugs, crank angle senor, checked wiring to injectors. Check wiring going into coils.. I guess I need to put a timing light on it next. I would also like to add an fuel pressure guage inside to verify fuel presure is not droping. Can not imagine why it would. Any thoughts??

09-21-2008, 09:47 AM	#2
cewrx7r1 The Judge Join Date: Feb 2008 Posts: 196 Rep Power: 18	Knock (really noise in this case) may be caused by engine/drivetrain parts hitting other parts or chassis. Shake the crap out of your engine and exhaust and listen for clanking. Ignition problem is most likely due to some of your rewiring.

09-21-2008, 09:35 PM	#3
sk8world 600rwhp club member. Join Date: Mar 2008 Posts: 551 Rep Power: 18	Chuck, Good point, I also added a 4 inch exhaust system. Maybe it touching a bit. I found a issue on the rewiring in the TB sensor.. Damn your good Chuck! Now give me 6 numbers below 50!