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  #21  
Old 05-08-2019, 09:26 AM
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babywag babywag is offline
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If you have questions on specific settings or what not just post up.
It may seem overwhelming all the info., settings etc. but lots of reading the manual a few times may help?

EFI is very dependent on good grounds, and good voltage.
Any fluctuations affects all functions of system operation.
If voltage drops fuel pump output changes, injector output changes, sensors provide ecm with different values etc.
So be 100% sure it's all good.
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'88 GW (aka Babywag) and '90 GW (aka JUNKbucket) both fuel injected
1994 Caprice wagon
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  #22  
Old 05-08-2019, 07:08 PM
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Crankyolman Crankyolman is offline
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Join Date: Sep 27, 2017
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Quote:
Originally Posted by babywag
If you have questions on specific settings or what not just post up.
It may seem overwhelming all the info., settings etc. but lots of reading the manual a few times may help?

EFI is very dependent on good grounds, and good voltage.
Any fluctuations affects all functions of system operation.
If voltage drops fuel pump output changes, injector output changes, sensors provide ecm with different values etc.
So be 100% sure it's all good.


Thank you Babywag, it is very intimidating but I'll work at it slowly and see what happens. I know all my connections are good and are soldered rather than crimped and my grounds are good. If there is a problem in the electrical system it's with the 30 amp Motorola alternator. My next planned upgrade is to a 50 or 60 amp GM alternator so I have a bit more juice.


I keep reading what is out there trying to understand it. To me Fitech seems to make things a bit vague but hopefully I will get to where I understand it.



This afternoon I changed the cold crank fuel settings from 0.0 to 3.0, which I hope isn't too much but when I started it after changing them it seemed to start closer to what I'm accustomed to. 5:30 tomorrow morning is when I will know something for sure.
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  #23  
Old 05-20-2019, 06:21 AM
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R69US R69US is offline
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Congrats on getting it up and running. I've had the FiTech on mine for a couple years now, and it's been good. There is a steep learning curve for sure, but if you are careful with tracking changes systematically I found it all starts to make sense pretty quickly. BabyWag covered the basics of the issues I had as well...any voltage drops, bad connections or ground issues will cause trouble. The cranking time on mine is a bit long as well, though it can be tuned out quite a bit as mentioned in the cold start tables.
If you're using the inline pump kit from FiTech, you may have to adjust the pump PCM settings down...it was set to 100% on mine, which isn't needed or great for the pump. I believe you can go down as far as about 65 as long as it doesn't affect AFR at idle.
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Old 05-20-2019, 11:26 PM
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Crankyolman Crankyolman is offline
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Quote:
Originally Posted by R69US
Congrats on getting it up and running. I've had the FiTech on mine for a couple years now, and it's been good. There is a steep learning curve for sure, but if you are careful with tracking changes systematically I found it all starts to make sense pretty quickly. BabyWag covered the basics of the issues I had as well...any voltage drops, bad connections or ground issues will cause trouble. The cranking time on mine is a bit long as well, though it can be tuned out quite a bit as mentioned in the cold start tables.
If you're using the inline pump kit from FiTech, you may have to adjust the pump PCM settings down...it was set to 100% on mine, which isn't needed or great for the pump. I believe you can go down as far as about 65 as long as it doesn't affect AFR at idle.




I've been doing a whole lot of reading trying to learn this fuel injection stuff. The guys over at a site called Fitechtuning have been helpful, unlike Fitech tech support. I keep doing little adjustments then taking it for a drive and seeing what things look like. IAC count was way too high but I've gotten that down where it should be. They tell me everything looks pretty good but there is something wrong with AFR giving it too much fuel. The theories about that are a vacuum leak or high fuel pressure. I've checked all the vacuum stuff and can't find anything there and it's pulling a pretty consistent -17 on vacuum so my next thing is fuel pressure. I just ordered a fuel pressure gauge and fitting today which should be here Thursday so I guess we will see what's going on there and get the PWM set.


I've been concerned about the PWM from the beginning since it was pre-set at 80 when everything I've read says it should have been 74.9. I also found something on Fitechs site that says that 74.9 is the preset for the frame mounted pump but if you are using the fuel command center you should reset PWM to 40. Although I am not using the frame mounted pump I'm not using the command center either but I am using the same pump they use for the command center only mounted in the fuel tank so I'm wondering if the PWM should be set much lower than it is but I need a fuel gauge to know for sure.


I was also reading on the tuning site about someone with a Buick 455 having trouble with slow cold starts. His solution seemed to be turning the prime shot off completely.I had planned to get the other stuff dialed in before I start dealing with that but morning temps are still below 50 here so maybe I should be playing with the prime shot before it gets too warm and see what happens.



All in all I'm pretty happy so far, Throttle response is really quick but I am still having trouble with the idea of not feathering the throttle when I start off and it's cold.
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  #25  
Old 05-21-2019, 03:58 PM
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R69US R69US is offline
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When I spoke with tech support R/ PWM settings, it sounded like the limiting factor is really just AFR stability at lower RPM. So he mentioned 65 as about the lowest for the inline. That said, my AFR was going lean when the pump got hot towards the end of the day (I was driving cross-country from San Diego to Austin at the time) so I ended up at about 75.
I haven't seen that website...I'll have to check it out. Interesting theory on the prime shot. Mine is set low for sure, because it was definitely going rich on the start. A lot of that was my fault, going the wrong way with cold start settings haha. ( I thought it needed more when it was actually too rich).
The only issue I still have is a slight hesitation/stumble off idle, almost like an accelerator pump problem, though adjustments in that table haven't made much difference. It just goes lean (like 15-5-16.5) for a half second off idle.
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  #26  
Old 05-21-2019, 10:14 PM
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Crankyolman Crankyolman is offline
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I'm just beginning to learn about this stuff. I haven't even begun data logging while driving but haven't noticed any hesitation whatsoever off idle. I did have it die on hard braking once and almost die another time, which from reading is a known issue caused by something called the DFCO which I guess helps save gas but they say it can be turned off with no ill effects so I'll probably do that. It's not really much of an issue for me, most days I drive 6 miles to work and 6 miles home and only one mile of that is above 40 MPH and don't usually brake too hard except when some idiot in a Prius or something like that pulls out in front of me and I need to scare the crap out of him by locking up my brakes. It's actually kind of funny to think about, we now have an entire generation of drivers who have never heard the horrible sound of locked up brakes followed by the crash because they have always had anti lock brakes.
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