alright i have a 388 built engine with the largest of everything i can run. i'm having problems starting the motor without holding the pedal to the floor. my tunner says because of the lack of vacum off the cam that's the only way possible to start this beast. anyone else heard of such a thing with tpi motors and any size combo???

 

WOT makes the engine lose vacuum. Who told you it was vacuum related? What did Greg say? PM me if u want

 

greg has no idea what's going on....

 

hmm, not sure...
does it seem like it's getting enough gas when trying to start with the pedal at idle? have you tried adding some gas to the inake to see if it fires right away?
flooring it should put the computer into flood mode, where it doesn't add much gas but allows air to come in through the TB.
have you checked your fuel pressure, made sure injector size is programmed correct....

i have a starting problem too, but i think it has to do with the engine being headless on the engine stand....

 

injectors should be right....they are working properly though as i have had them flowtested. as far as the fuel i had a problem of running to rick at startup so alot of fuel has been pulled. i have upwards of a 15:1 a/f ratio just to start it. i'm running 30lb svo injectors at the lowest possible setting i can adjust my fuel regulator at which is roughly around 30 psi yet gas mileage is still kind of low and it doesn't start well.

it really doesn't make much since to me??? you almost have to play with it like a carb.

 

there are settings for the intial timing while the engine is cranking, maybe the programing is off there. my buddy just got the software and romulator to program his car, maybe you should call him sometime, if you want, pm me and i'll send you his number.

 

JUST GET A DFI SYSTEM AND GET OVER IT...
common jeff you have the best of everything but you skimp on stuff the really would solve all of your problems..
example: a 90 blue notch of a friend of mine went apeshizdity trying to get his 306 ford tuned with a stock computer... a few months later he picked up a fast system with wide band o2 and you can take a laptop and plug any af ratio and the car will build it's own fuel map.........
old technology will only cause problems, time amd $$$$$$$$$$$.
or f... it and put a CARB. on it.... i love mine.

 

well i'm not sure his intensions with his car but it has been recomended not to use the fast dfi units for street driving, they are a computer based on WOT tuning, great for the track poor for the street.

but if all you do is race it, heck yeah, get a fast dfi!

 

it's a street car....needs to be dependable. the damn thing runs great it just won't start right. i went out to the tuners last night to check the progress and the damn thing would start at all...turned over but looked like the plugs may have been fouled out. replace the tps sensor since the laptop showed my stock one going haywire.

i'm pretty much at a loss, plenty of people have claimed they can tune it but the fact is i have yet to find the right answer.



as far as dfi....yeah i probably would do that if i already didn't have over 800 in parts alone for the speed density setup.

 

ok, i talked to my buddy some he thinks it's not getting enough fuel.

try this, put your fuel pressure back to norm. 40-45psi.
in the computer, change the cranking air/fuel ratio to 9:1

if that doesn't work go richer, he's heard of some people going to 5:1 a/f while cranking.

he also said there's a spot for a "decay factor"
the rate from which it goes from cranking a/f ratio to the idle a/f ratio.
you may have to change that as well.


try that out if you can.

ttl,
mike

btw: what model of ecm are you using?

 

the ecm is the stock piece that came with my 1991 l98 car. i'll try the fuel type you suggest however it's already having a hard time fouling plugs??

i'm replacing the ecm as well since it may be a problem being old....thank you for the suggestions and if anyone else comes up with anything please let me know.

 

when you access the pcm it should have a sticker on the side of it with a part/serial number, somewhere around 14 numbers long.

the one in my astro ends in 7747, which is a popular one, you may have the same.

another popular one i think ends in 903

it makes a difference what can be changed.

as far as plug fouling, the rest of the tune may still need adjusting after you clearup the starting issue.

one thing at a time. you can always go back to what you have programmed now.