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I'm running kelford 280 cams, fic 1450 injectors, walbro 450 pump and 93 octane with an fp black on speed density. Car runs and drives great but on startup it takes 8-10 seconds to start. Sometimes I have to stop cranking because it's taking so long to start and then try again. I'm assuming the car is getting too much fuel ( sometimes it sort of sputters but doesn't actually run ) but I have no way of knowing for sure. I've tried playing with the isc while cranking and after cranking settings with no luck. Can someone give me settings they are using so maybe that will help me figure out where I'm going wrong / give me a good starting point? Any help is greatly appreciated!!
As a side note, it doesn't seem to matter if it's hot or cold, it doesn't start well either way. The only time it starts remotely decent ( still not great ) is if I shut it off and immediately restart the car. All parts are new.
It's usually because your FPR is junk and it bleeds off the pressure after you shut it off.
Once you measure the pressure, you'll know what's going on.
Assumption is the mother of all feckups.
So is trying to use software to fix a hardware problem.
That's very possible although this wasn't a problem until I swapped fuel pumps and upgraded injectors. Is there a spot I can easily tap in to put a gauge or do I basically need to replace the fpr for an aftermarket one that has a gauge on it?
It's usually because your FPR is junk and it bleeds off the pressure after you shut it off.
Once you measure the pressure, you'll know what's going on.
Assumption is the mother of all feckups.
So is trying to use software to fix a hardware problem.
OP do not listen to this guy. He seems to think everyone's problems are tied to fuel pressure.
If you haven't seen this thread I would recommend checking it out. It's an in depth writeup of how the startup and ISCV tables work and how to tweak them. One method that worked for me when dialing in my startup was by simply looking at my wideband gauge and monitoring it. If the car doesn't start and the gauge reads rich then I know I need to dial back the startup fuel table. If the car doesn't start and the gauge reads lean then I need to add fuel. You'll know you are getting close when the engine starts to cough.
OP do not listen to this guy. He seems to think everyone's problems are tied to fuel pressure.
If you haven't seen this thread I would recommend checking it out. It's an in depth writeup of how the startup and ISCV tables work and how to tweak them. One method that worked for me when dialing in my startup was by simply looking at my wideband gauge and monitoring it. If the car doesn't start and the gauge reads rich then I know I need to dial back the startup fuel table. If the car doesn't start and the gauge reads lean then I need to add fuel. You'll know you are getting close when the engine starts to cough.
Between 13 and 14. The car will still start even though your AFRS read slightly lower or higher than those values. You can then fine tune it by following the instructions in the thread I posted.
Then: Below 45F multiply the values by 0.42
leave values at 45 and 68
anything above that : ad the latency time in ms @ 10V so app. 1.6ms
start IPW Latecy should be set to 1.6ms also
Than start the car from full cold, log the engine temp.
If the temp is close ( less by a few degrees F ) to one of the IPW during cranking temps, switch off, wait for main relay to shut off ( 5-8 seconds )
Start the car again every time...so you will feel if the car is responding right to the Start IPW....AT THAT TEMP
Then you can fine adjust, mostly you will need more above 68F and less below 45F..
45F and 68F itself will have to blended ( interpolated ) in to get them right
Then: Below 45F multiply the values by 0.42
leave values at 45 and 68
anything above that : ad the latency time in ms @ 10V so app. 1.6ms
start IPW Latecy should be set to 1.6ms also
Than start the car from full cold, log the engine temp.
If the temp is close ( less by a few degrees F ) to one of the IPW during cranking temps, switch off, wait for main relay to shut off ( 5-8 seconds )
Start the car again every time...so you will feel if the car is responding right to the Start IPW....AT THAT TEMP
Then you can fine adjust, mostly you will need more above 68F and less below 45F..
45F and 68F itself will have to blended ( interpolated ) in to get them right
Thank you, I will give that a try and report back shortly! What exactly does the start ipw latency setting do? Doesn't it go off of the during cranking numbers anyways? I just looked and mine is set for 432 ms but I checked my old tune from before where the car started perfect ( smaller injectors and different tuner ) and it's 432 in that tune also. Are you sure you meant 1.6?
Last edited by 1fast97gsx; Jan 27, 2017 at 06:22 PM.
yes, i mean 1.6ms equals 1600 microsenconds...but i figured out that the rom doesnt allow that ...sorry for that, was working with an different car ...
Stock is 432 microsenconds, so set it to 800 for first test
It comes into play only when the Car is warmed up to temp and restarted.( so short PW needed )
It is the latency during start before the engine is running, ie cranking
This also comes into play when having slow injectors. With PTE 780 it doesnt need to be changed....
yes, i mean 1.6ms equals 1600 microsenconds...but i figured out that the rom doesnt allow that ...sorry for that, was working with an different car ...
Stock is 432 microsenconds, so set it to 800 for first test
It comes into play only when the Car is warmed up to temp and restarted.( so short PW needed )
It is the latency during start before the engine is running, ie cranking
This also comes into play when having slow injectors. With PTE 780 it doesnt need to be changed....
Oh ok that makes sense. I'll give 800 a shot. When I see "ipw enrichmment vs. coolant temp 1 and 2", what is the reason for having 2 tables. In other words, why is there a 1 and 2?
i am not really sure when any of them will be used...
I believe that number one is the main one..
But these are only applying when the engine is running....
So, first you have to get your cranking problem done...
Jan 26, 2017, 08:25 PM
