I dont want my computer to learn! We took the cougar out for the firts time this year and it ran fine for the first 5 miles or so but then started leaning out to the point of misfireing.:mad: I really need to get it on a dyno but dont have the money at the moment, so Im hoping for a temperary fix by disconnecting the memory wire, anyone know where it is? I hope it will work or be in the same location...I have a mustang computer and a painless wiring harness. I have chip also(for my old set up)..would removing the memory wire affect it working? This year we went with TFS R-box intake, Accufab 90mmTB, 42lb injectors and I think its the lighting Mass Air Meter giving us the problems. Today Im going to try putting the old sensor back on to see if that helps. Thanx!
It's pin #1 a Black/Orange wire in the stock harness... Dunno the color on a afternmarket but its still pin #1
BUT disconnecting it will not stop the EEC from learning, it just causes it to forget what it's learned while running when you cut it off... So what to do???? Also disconnect the o2 sensors... The EEC then doesn't have enough info to learn, so you can set fuel pressure and it hasn't a clue...
BTW the MAF meter must be matched to the injector size... The factory setups usually matches the EEC to a comon calibration MAF.. The aftermarket MAFs are recal'd to allow larger injectors on the stock EEC... Maybe the Lightnings are different but you'd be wise to check... BTW my '93 is Speed Densety... I really ain't familiar with the 2nd gens..
The MAFs is cal. for 42lb fuel injectors since its off a lightning... same size Im running. I have a chip also set to 42lb injectors. This car is making me so mad. You mash the gas and all that happens is a bunch of sputtering a missfires then all of a sudden the fuel kicks in on the meter and the car flys!
I just want to try the memory wire but we didnt even think to disconnect the o2s....so Ill try that too.
Were also going to check for leaks cuz its rich when you first start it up then it seems like it loses pressure??? Then the TPS then Im sending it to the junk yard! HA! Yea right! Thanx..any other advice for me? You always have the best info!
Is it a vac actuated FPR? if so i would start there,, meaning,,
determine if there is a piece part that delays the vac presure to the regulator.
sounds like your saying that there is a delay in fuel delivery
if it were stock , id also suggest cleaning the MAF and the O2's.
did you guys end up with the true 347 pistons or the revised ones? i cant remember but i do know that you have had this setup for about a couple years now. I was interested in the oil consumption if you had the true 347 pistons.
aeromotive FPR it is vaccume, the fuel doesnt kick in when ya need it, but its just got a strait vaccume to the intake. We put the box R intake on it cuz it had so much vaccume last year it sucked the vaccume lines closed... maybe we dont have enough now:dunno:
I took the o2s off and that did help some, it didnt misfire-yet-it was a short test drive.
What do you mean true or revised pistons? We got the whole set up in a kit 4 years ago it said for better oiling??? It doesnt use any oil.
Which MAF do you have and how big is it?
2002 lightning in a custom 90mm air tube. We have 42lb injectors so does the lightning. Ive been looking more into it lately and I see they use 2003,,,I dont know if there is a difference or not. Puting our old MAFs on did nothing...
We got it drivable but it still leans out. The FPR is set as high as it will go 75psi and 02s are off. I guess it just needs to be tuned for the bigger MAF, the chip thats in it now has the fuel injectors tuned down for last years set up so that must be the problem. Anyone know if Motorvation can re-program chips?
How big of a pump are you running? 75 PSI is quite high for fuel pressure ( I run 60 and am not happy that it's that high).
The more fuel pressure you run the bigger your injector acts. 60 PSI on a 19 pound injector would actually make it flow as a 24 pound injector would at 40 PSI. The reverse is true for a fuel pump. The more pressure you run, the less flow (pressure slows the impeller down).
For example, I run 19 pounders at 60 PSI, but I back them up with a 255 LPH pump. Even though your pump may be big enough for 42 pound injectors mathematically, at 75 PSI your injectors are acting like 60 pounders. Even a 255 pump would not be enough for this setup. I'd recommend at least 325 LPH pump flow with your setup.
I have a 255 high flow pump. I wouldnt think Id need any bigger than 42lb,,,I have no idea what the hp is but 42lb should be good up to,,,what... like 600hp? Thats why it makes no sence to me why the fuel pressure would need to be that high. Thats why I thought it could be the MAFs or the chip,or maxed out the computer even. I figured it should be getting plenty of fuel and something was leaning it out. I know last year we needed to run that NOS octain boost, it was the only thing that car would run on, I dont know where to get race gas to see if we just need better octane. compression is just 10.4 - 1.
Last night we took it for a test run and it just started misfireing,bucking and lean pop'n and over heated We came back... pulled a spark plug, and it was white? So I dont know how it ran so good one time but the FP being up isnt even helping it now...and that car has never over heated before!
Like I said, the extra fuel pressure will actually make a pump put out less fuel than advertised. You 255 at 75 PSI is likely giving around 200.
OK it's a 347.....Oooh found your specs......
I see in your posts you went to a 90 mm throttle body and box style intake as well.
As long as your not spinning this motor over 6500 RPM's I dont see why 42 pound injectors set at 40 PSI wouldn't be enough. A 255 pump should be more than enough at that fuel pressure and 42 pounders. Why do you have a chip anyhow?
Something that hasn't been mentioned... You need to be sure the F/P is maintaining at full throttle. If the pump or fuel system has a issue the pressure may be dropping...
Also you can run it breifly without the MAF meter to check how it reacts to different F/Ps... With no memory, o2 sensors, or MAF it should be really rich with the pressure set that high...
I got the chip last year for better tuning...I think they tuned down the fuel injectors and we got any hesatation out but thats it. I wont buy another over the phone chip again.
I have a F/P gauge hooked up at the regulator, I didnt have the right fittings to do it on the rails. I dont know if that makes a difference or not? but the F/P doesnt drop.Taking the MAFs off will make it run richer? I thought it would just run like shiznit..Ill try it after I get the front end back together.
Ive tested with the chip out too cuz last year the car ran rich. All thats changed is the intake, T/B, MAFs, and bigger long tubes. Dont take it the wrong way though the car has a very noticable amount more power. In fact Ive noticed the roll cage hits the windshield and :( the passengers side sits an inch and a half lower than the drivers. I got new drag springs for the front tho...it might just be the spring, theres no spring left in the pasenger one. I also put KYB adjustables on it and cant get any weight transfer.
You know how I said we got the car to run driveable only once... well after putting it back in the garage we decided to check the timing (again) and the car wouldnt start... the battery was dead...some how the alternator came unpluged:dunno: That could have had something to do with it running shiznitty for a second test with nothing different. not enough power to the MSD dig. 6 and maybe the pump?
Im also going to check the fuel injectors, We reran some stainless line and maybe some rubber got to them. I already checked one tho and it was fine but cant hurt.
The pump is going to require full voltage to maintain good flow with the pressures you are running... But as long as fuel pressure doesn't drop under full throttle it should be OK, but maybe not with the MSD.. Another thing, you may want to try removing the chip and cleaning the pins on the EEC and chip...
All the MAF does is contribute info to the EEC so it can set fuel mixture... Without it and playing with pressure, you should be able to make it run at WOT although it will run like po po at all other speeds...
Quite true.....
I'd see how it runs WITHOUT the chip installed and drop the fuel pressure to 50 as well to see if there is any noticeable difference.
If the engine is stroked, It will draw in more air per rev. The computer is set(without chip) to a certian amout of air per rev. The chip (SCT) can change the engine displacement. The will alter the Maf curve and the injector timing and duty cycle.
The computer will run on a base cold start table for a given time and then change over to the base fuel table. That would be the reason for the leaning out after a short drive. So the memeory wire will not stop you lean condition.
Do you know what type of chip you have?
I'm a SCT dealer if you have that type I can reburn it for you.
A off the shelf (hypertec,ETC.) chip will not work with you set up. You need a custom chip set up for your application. Espically with the N20.
hmm, i'll bet fast cat knows a thing or two about chips...
I thought changing the engine displacement would change load scaling, not alter the MAF curve.
Do you mean base open loop, or the startup table?
The computer uses the Maf to determine LOAD.
Cold start up table then it switches to the base fuel table.