VTC_CiViC

Here's my setup --> '98 Civic EX, GReddy TD04H-15G, RC 440cc injectors, Walbro 255lph high volume pump, VAFC.

Here's my situation --> Car runs erratic, stumbles, dies out under hard accel.

Ever since I installed the 440's my car has been running really "buggy", little glitches here and there and I'm thinking I may be drowning it w/ fuel. I've had like 3 or 4 CEL's in the past 3-4 days, all related to either MAP or BARO sensors. I had my injectors trimmed -50% via the VAFC which I belive is why I got the last CEL which was a code 5 (MAP signal range insuffeicent, error). I figured that since I was trimming so far, the same way the MAP freaks if it sees too much voltage (boost), it must not like seeing too little vaccum either. So I upped the idle to -40%, thus far no problems.

Driving has been another story. At first, upon making some full throttle runs, the car would get to around 5k and just suddenly die out completley, like I hit a wall, and could here this gurguling/mumble/sputter from the exahust till I let go of the throttle and it was fine again. I then noticed that when I free reved the car in my garage, it did the same thing, at around 5k rpm, the car would just wouldn't accel. anymore and would sputter instead. It was then that I though "ok, maybe it's too rich?". I lean it out from -15% @5k to -30%, car now pulls fine through the redline with only a small hesitation around 5.5k which it pulls out of quickly. Now I know you're thinking "why not just use the A/F gauge to tell you how you're running?". Well I've come to relaize that my Autometer A/F gauge is nothing more than a nice electronic paperweight, completley and utter useless. Ever since I've gone turbo months ago, I simply cannot get the dam thing to read rich except when I first start it and it's cold. Once warmed up, it never reaads out of stoich...never! Now I only fill up with 93 octane (usualy Chevron or Mobil), timing is retarded 2-3 degrees, and I check my plugs weekly. I never once heard a single ping, and my plugs always look the same (light greyish/off-white, no "hot spots" or deformation, no damge to the electrode or insulator). Based on my plugs, I'm thinking I run just fine, and even now wih the damn 440's in there, my A/F gauge still reads nothing but lean and stoich.

So here's my "possible" soulution. I have an H22A and stock D16Y8 fuel pump sitting in my garage. With the RC 440's pumping as much fuel as they do, should I revert back to either the H or D pump rather than my high volume Walbro? I'm thinking this will help reduce the amount of trim I use via the VAFC, therefore letting my car run a little more "normal", like before I went with the 440's. Right now I get sparatic periods of jumping idle (from 600-750 over and over) and points where if I'm at 5-7% throttle, the car will suddenly stop accelerationg altogether even though my foot is still on the accel., then out of nowhere jump forward and accel again. Since I'm doing so much altering with the VAFC, I belive this may interfere a little with the way the car manages itself and other sensors. I know this is long but i'm hoping some of you guys (Dustin, dbman, SgT etc..) will help me deicde should I swap out pumps, any other pointers?

GSRacer

you should try 310's

rtype11

dont have the attention span to read your whole post, think I got the Jist of your message though. Please have someone tune your car for you. your plugs have seen lean conditions from the colour you describe, but obviously you also run rich at other times. get in there with your computer whtever with someelse and monitor a/f - you are obviously all over the place and do not have your fuel setup right for the vtec to kick in at abt. 5k rpm. make sure your fuel PSI is decent dont go over anything like 50 in the line. also have you tricked out your MAP sensor??? your car cannot read anything over the 1bar MAP (abt. 11 psi the ECU can actually see) are you going over this??? get a check valve(s) in there.

Get the HALMETER for 139 or whatever or go to a dyno with wideband. invest in some good setup tools lie dynos and AF otherwise it will be more expensive to fix afterwards. - shirt my post is like as long as yours now!!!!!!!!!!!!!!

D-Man

injectors are too big,,get 310cc

GGrahnVI

Do you have an EGT gauge? If not, buy one.

VTC_CiViC

No EGT, though I can see my A/F is a royal POS hence i'm going with an EGT soon. I do intend on having it dyno tuned at SFP soon, though so far nobody has mentioned the fuel pump question I was asking. As for the 310's, no thanks, I don't want to deal with high pressure fuel pumps and FMU's.