jrdnclrk Posted January 10, 2022 Report Share Posted January 10, 2022 Hello all I've been trying with no luck in any direction to get my car to cold start. The car already has the base map tuned. it's running 1000cc injectors, 1zz coils, stock iac, stock map sensor, stock tps, stock IAT, wideband is plx has a start point ground to the cylinder head, battery is relocated to rear. fuel pump is ran off the key, battery is a brand new optima red top. UPDATE!!! problem solved below Here are the issues laid out: 1. will NOT start at all when cold soaked and cranked with the starter at anything below *60 ambient 2. after cranking for a brief period trying to cold start. keying off and keying back on will cause a tremendous exhaust back fire. things I've noticed are the car will start pretty easily if push started using a hill, in gear and popping the clutch. I've tried a variety of settings in the cold start side of fuel from very little crank enrichment to a whole lot. with no changes. I've changed dwell settings on coils with no luck. this is going on 3 months of little changes with no luck. I'm certain it's most likely and issue with voltage getting too low for something while cranking due to the starter pulling so much power but I've too little experience in trouble shooting aftermarket cold start issues. Quote Link to comment Share on other sites More sharing options...
essb00 Posted January 10, 2022 Report Share Posted January 10, 2022 Just a quick look at your map... 1. Your pre-crank prime dumps too much fuel at key on - probably why you're getting back fire. 2. You are having trigger errors. Try to lower your trigger arming threshold to values as per below. Maybe a good idea to post a trigger scope log so we can try to see what's going on. Most probably because of the trigger error why you're also not getting any coil dwell in the logs (not firing the coils at all). Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 11, 2022 Report Share Posted January 11, 2022 Yeah I have similar thoughts. Mostly looks like a trigger issue. Do a cold trigger scope when you can and that should give us some clues where the problem is. The battery voltage is very low so it will help if you fix that. Your trigger setup is odd - does it have a VVT crank wheel and a non VVT cam trigger? jrdnclrk 1 Quote Link to comment Share on other sites More sharing options...
jrdnclrk Posted January 11, 2022 Author Report Share Posted January 11, 2022 On 1/10/2022 at 5:17 PM, essb00 said: Just a quick look at your map... 1. Your pre-crank prime dumps too much fuel at key on - probably why you're getting back fire. 2. You are having trigger errors. Try to lower your trigger arming threshold to values as per below. Maybe a good idea to post a trigger scope log so we can try to see what's going on. Most probably because of the trigger error why you're also not getting any coil dwell in the logs (not firing the coils at all). On 1/10/2022 at 11:11 PM, Adamw said: Yeah I have similar thoughts. Mostly looks like a trigger issue. Do a cold trigger scope when you can and that should give us some clues where the problem is. The battery voltage is very low so it will help if you fix that. Your trigger setup is odd - does it have a VVT crank wheel and a non VVT cam trigger? i adjusted tigger threshold to the above setting and finally got some fire out while cranking. its still cranking over slow and not wanting to fire. ive got a trickle charger setup on the battery to ensure its fully charged all the time but it doesnt seem to care. i'm also suspecting my battery to starter cable may have higher than normal resistance. and yes im running a non vvti head and vvti crank trigger wheel because its what i was able to source more easily than a non vvti trigger wheel. Quote Link to comment Share on other sites More sharing options...
essb00 Posted January 11, 2022 Report Share Posted January 11, 2022 You're still getting trigger errors there. Do a trigger scope log then post it. jrdnclrk 1 Quote Link to comment Share on other sites More sharing options...
jrdnclrk Posted January 11, 2022 Author Report Share Posted January 11, 2022 On 1/11/2022 at 1:25 PM, essb00 said: You're still getting trigger errors there. Do a trigger scope log then post it. Hello thanks again for the help! I was able to resolve the issue by changing the way my pre crank prime works. I had previously had it set up to precrank prime as soon as the ecu is keyed on. i changed it to as soon as the ecu see start signal. i also added an input for the start signal to digital input 2. all is well car now fires up easily and the main problem is resolved! essb00 1 Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 11, 2022 Report Share Posted January 11, 2022 Dont think so, you last log still shows a significant trigger issue, low battery voltage and low cranking speed. Quote Link to comment Share on other sites More sharing options...
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