91jdmhatchback

ok i have been having this problem for awhile now. and it is geting rediculous.

ok my set up as follows:

91 civic lx
- mpfi and obd1 swaped (used boomslang harness)
- dsm 450cc injectors
- chipped p28 ( custom d15 map)
- t25
- 2.25" dp/exhaust
- side mount ic

ok the car is street tuned as close as we could get it with the wide band. it runs very good in boost and out. it runs slightly lean when cold till it warms up.

now i can go damn close to WOT but if i hit wot it just cuts fuel, and doesn't do anything till i go lower throttle position.

i adjusted the tps sense it was slightly off, but didn't through a code for it or anything.

it throws no codes at all. i also have the o2, vtec related, is all desabled

i would have the o2 hooked up but at the time i had a bad o2.

so what could it be?

btw i am on stock fuel pump.

0mtber

iTrader: (2)

What spark plugs are you running & at what gap ?
What air fuel ratios are you running in boost at full throttle ?
Did you consider trying another distributor ?

HiProfile

Is it your chip? What EMS? Sometimes boostcut is set, ectune for example starts with boost cut at 3psi for me. That or your WG is not opening/overboosting.

91jdmhatchback

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">What spark plugs are you running & at what gap ?
What air fuel ratios are you running in boost at full throttle ?
Did you consider trying another distributor ?
</TD></TR></TABLE>

i'm running ngk bkr7e11's gaped down to 25-28.

in boost i'm right in the 11.7-12.5 range depending on where in the rpm's, this was a temp tune till i get to the dyno so we set ign. retard at .75*/lb boost.

my dizzy has a new cap/rotor, coil but the ignitor is whatever came with it. also my plug wires have seen better days. there the stock ones

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">Is it your chip? What EMS? Sometimes boostcut is set, ectune for example starts with boost cut at 3psi for me. That or your WG is not opening/overboosting.</TD></TR></TABLE>

i have 2 chips that we used to tune it, and they both work and both do the same thing cut fuel a WOT only. i can boost fine part throttle, just not WOT.

crome pro is what i'm using

we took off all fuel cuts/ boost cuts. sense we did experience a problem with a 3k fuel cut. but we were throwing codes also so idk on that.

i boost a solid 10-9 lbs depending on the temp outside. i never had a problem with the amount of boost i'm running.

thanks for the repleys

hope i can figure this out

90lsvcrxva

mine was doing same thing im on trial chrome. But mine would hit 10 pounds and cut out&gt; Was to rich on top stoped doing it when we leaned it out. Now running like a 10.8 on top little rich but still runs good. car got 10 pound spring with tial gate and will creap to 14 pounds and afrs stay around 10.8 with stock map.

HiProfile

The problem with 9-10psi is your are basicly at the edge of the stock MAP sensor's range (you didn't mention a diff sensor used). Go above that and it will inject the same amount of fuel (and timing) as it does for 11.2psi.

If you are getting CEL's now, you must get them resolved before you can even think you can start tuning. It takes 5 seconds to pull the codes, which is why it irritates me when people don't look them up. 90% of the time a CEL code # will put you on the right path, if not tell you your exact problem. Removing boost cuts should never end up with a 3k limiter or a CEL, which is indicitave of it going into LIMP mode.

I would strongly suggest completely restarting a new Crome map for it, then copy/past the fuel & ignition maps over. Get all the settings correct, then see if that fixes it. Other than that, what you've said doesn't give me any more ideas.

91jdmhatchback

yeah well we did copy paste in a new map. and this is the results. there is no check engine light at all.

it makes no sense. there is no rpm/ boost that it will cut at. it is totally just wot, thats it.

90lsvcrxva

sounds like fuel cut to me!

CoreyR

we had the same problem on an obd0 car and we never could figure it out, you could go 95% full throttle and it would make full boost and run fine, but if you pushed the pedal to the floor it would just break up.

im curious to see what you figure out.

91jdmhatchback

yeah i'm going to try and figure something out this weekend.

but i'm totally lost

RC000E

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CoreyR &raquo;</TD></TR><TR><TD CLASS="quote">we had the same problem on an obd0 car and we never could figure it out, you could go 95% full throttle and it would make full boost and run fine, but if you pushed the pedal to the floor it would just break up.

im curious to see what you figure out.</TD></TR></TABLE>

Yeah, I'll second that. I currently have a friend with an OBD0-OBD1 converted hatch, LS motor, running CromeGold.... It won't hold a stable air/fuel and cuts out at wot. According to logs it's just randomly shutting off the injectors for a split second...no indication as why though. We're rebuilding another entire harness just to be certain there's no issue, because my brother wired it from my instructions versus me wiring it myself. This seems eerily coincidental though.

91jdmhatchback

i mean what could be causing this?

did you use inline resisters? i did.

mine feels identical to fuel cut, but it holds till i let off again.

damn this is frustrating

CoreyR

only diff in my case was that we didnt have the car converted to OBD1 it was a 90 Si with a stock A6 motor running a chipped PM6 and turboedit

RC000E

Nope, in my case I used the typical honda resistor box.

In the crome logs the injectors are clearly shutting off. There's some type of issue that's very elusive. Like I said, I'm going to build an entirely different harness just to eliminate it as the issue. I have no real answers though. I've used a different ecu, dizzy, pinned out the dpfi to mpfi wiring, checked grounds, etc. I'm just changing anything and everything at this point.

evosix

this maybe a long shot but how much fuel do you have in the tank? I had the same issue, hitting fuel cut; filled up and problem is resolved.

91jdmhatchback

it does it no matter the amount of gas in the car.

thanks for the help

92civiceg9gsr

Sounds like the MAP sensor to me. OEM can only read ~10psi.

fastludeh22

iTrader: (1)

you know anyone with s300 or anyother besides what your running? try swapping ecu's with somone for a day, see if your car gets fixed/they're car starts doing it? maybe ecu, maybe prog related? as long as wide band is in the car, should be easy to try for a day...

91jdmhatchback

i don't know anyone running on a stock map sensor

so that kinda sucks.

boosted97civic

get a 3 bar newb lol

fastludeh22

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted97civic &raquo;</TD></TR><TR><TD CLASS="quote">get a 3 bar newb lol</TD></TR></TABLE>

lol, i have one for sale, buts this isnt the place for that... my only experince is with hondata, but you can just change the type of map sensor in the settings and not screw up the map...

CoreyR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92civiceg9gsr &raquo;</TD></TR><TR><TD CLASS="quote">Sounds like the MAP sensor to me. OEM can only read ~10psi.</TD></TR></TABLE>

its 11 and it doesnt matter, it can still have more then 11psi thrown at it but it will only tune as far a the 11psi column, it wont cause a boost cut unless one is set to that specific pressure.

91jdmhatchback

could i be running out of fuel pump?

could i test this by hooking up a fpr gauge and checking if the pressure falls off?

or does it sould like the injectors are shuting off.

i'm going to watch my wide band and see if i can see the a/f go crazy or something.

so frustrating

RC000E

have you tried actually putting a multimeter on the tps and manually going to wot by hand to be sure you going from .5v-4.5v? I've seen tps's go bad, but not throw a code. I recently replaced a sensor that would only go from .5 to 2.7v and no further...had a very similar issue.

91jdmhatchback

yeah thats how i adjusted it, with the multimeter on it and manually moving it with my hand. it is set to spec.

the injectors are for sure shutting off, as i go instant lean when it cuts.