xdevenx

I'll start from the beginning. installed a JET stage 1 chip the other night (I know, better off burning my own, so we can skip that) After the drive to work the next morning, took it right back out.

I also installed an airfoil, noticed smoother throttle, but at idle it was very rough, figured it was due to computer relearning and dismissed it. also had at least one injector stuck open, dumping fuel.

Today I installed a new set of Bosch III's i got from FIC. no more over fueling, acceleration is awesome and smoother than ever, but it still has that rough idle after yet another computer reset....My question is, is the rough idle just the computer relearning? Or is there an issue with the air foil?

also, no vacuum leaks, all gaskets good, sensors good, tps adjusted to .54. Timing is set to 5 degrees BTDC. just to get a few of the obvious questions out of the way. Anyone who can point me in the right direction?

xdevenx

ok, removed air foil just to see, made little to no difference. really stuck here, anyone have an idea?

james.gould150

egr?iac? maybe check those...spark plugs/wires/coil?they could be on their way out if old ...just some thoughts

xdevenx

iac was just replaced, egr is blocked off, was disconnected for a year before that, haven't checked plugs, but wires, cap and rotor are all good. coil is new, done about a week before the plugs about a year and a half ago. what's tripping me up is that under acceleration it's perfectly fine, its just the idle thats rough. and i'm not smelling any unburnt fuel.

james.gould150

it sounds like something in the computer possibly need a new ecm? or get a prom that is in a car that runs fine and see what yours does? i do not know much about the electrical end of things but what i do know is that if a chip isnt stored properly any bit of uv light (ie. sunlight or just bright light in general) they can goof up on you..i dont know how the relearning process is with these cars i had a honda though that you had to drive it for 20 minutes normally to relearn,but i dont know if that will help ?

xdevenx

hopefully not a new ecm, just replaced that three months ago, definitely hoping its not a prom issue, those are even harder to find

james.gould150

nah proms are found pretty easy junkyards have them a dime a dozen...plus there are ppl on TGO who burn custom chips for a fraction the price of what they go for like jet or hypertech...i forget where i read it but one guy will burn a chip for like 100$ anyway you want it (even stock) all you gotta do is send specs (unless stock) and a stock prom

xdevenx

yeah, the bad part around here is when a tpi car goes into the jy, its usually stripped before it ever hits the yard. i'm hoping at this point that after i drive it for a few days it will level out. from what i remember, it takes a few cold starts for it to completely relearn...we will see

james.gould150

good luck !!

xdevenx

thanks, just in case, anyone know where i can get a prom? again, just in case.

old z mzn

iTrader: (1)

mass airflow you might want to check?

Street Lethal

iTrader: (16)

Is she running rough at idle when cold, or only when warmed up? Without a scanner it's like shooting arrows in the dark, because if you know where your BLM's are in closed loop (if your even reaching closed loop), as well as what your Coolant Temp Sensor is telling your ECM, it would make it much easier to diagnose....

xdevenx

once it's warmed up it's a lot better, still can't really describe what its like, almost like its idling too low, but the tach says 750. (as reliable as that is). Forgot to list another part, i also installed a new IAC housing to eliminate the coolant passages, im thinking the IAC may be overextended, gonna check it tomorrow. It's the only thing that makes sense to me because there are absolutely no other symptoms other than poor idle.

james.gould150

Mine just started acting up again...before I couldn't accelerate and would stall comming to a stop...now when it warms up it idles poorly and very low around 500rpms sound familar? Ha I think it's either tps voltage or iac not set right ugh back to work wth this thing

xdevenx

does sound familiar, let me know what you come up with, ill do the same

james.gould150

havent tried anything yet but driving it home from work it stalled on me at about half throttle,started right back up , but the i had no power and i can smell fuel...im gonna check and see if it threw a code to the ecm via paperclip...i think my mechanic is an ****** ..i think it may have a ruptured fuel line and/or injector leaking out the seal i havent even had it back one full day and im getting more problems ill post more when i look at it tomorrow it limped the last mile home and its past midnight here so im gonna sleep on it

xdevenx

IAC is good, while checking things with the car running, unplugged the TPS and the idle leveled out, haven't checked the voltage yet, but could this be a sign the TPS is bad?

xdevenx

finally hooked up the scanner, in closed loop getting High INT and BLM numbers, 134 and 155 respectively. No vacuum leaks, TPS is good, IAC is good, MAF is good. i'm stumped here, its running rich to the point of giving me a headache, im stumped.

Street Lethal

iTrader: (16)

Above 128 BLM is a LEAN condition, not rich, as your ECM is adding fuel to compensate for too much oxygen. Check your fuel pressure, as it might be too low, as well as check your injector ohm, as some of them might be on their way out (even though they're new)....

xdevenx

Yes, computer is recording a lean condition, but the exhaust is telling me there's too much fuel as for Injectors, haven't ohm tested yet, but they're a week old. Fuel pump is within a year old. Looked at a spec chart at my shop and it calls for tps to be set at 1.25 volts at idle, when everything I've read says .54 which is where its set.

james.gould150

I've discovered I have a faulty fuel pump that may be the cause I ordered a new one this a.m when I install it I'll update with how it runs, it seemed ok but it won't stay pressurized very long and I have new fpr and 1 new and 7 cleaned injectors and new filter I will keep you updated

Street Lethal

iTrader: (16)

How is it telling, by a smell that can be coming from anywhere lol? If the smell of fuel is getting to you, then it is obviously coming from the engine bay, and not your tailpipes. If O2 correction is reading lean, then the ECM is dumping more fuel to bring BLM's down. Just because you are smelling fuel does not mean you are running rich, as the scent of raw fuel can be coming from anywhere, even by the vapor canister filter, which would be the reason why you are running lean in the first place. You can tell me over and over again that the injectors are new, and that the fuel pump is okay, but only your fuel pressure will tell the actual truth. What is your fuel pressure? Have you pulled your plugs to see if you are running rich, or are you basing the rich condition solely on the scent of raw fuel? BLM's are reading lean, yet you did not confirm fuel pressure as of yet, and you do not know what your plugs look like. The scent of raw fuel can be coming from anywhere (eg; fuel filter fitting leak, regulator diaphragm leak, hair line crack in a fuel line leak, vapor canister filter, etc), and is more than likely the reason why you are running lean because pressure is dropping and not making it to the injectors. Check your fuel pressure, and don't base everything on smell, and if you are, is your exhuast at least black indicating rich....?

james.gould150

my car was very mysterious as it seems to be with most t hird gens with fuel issues...mine was a number of things ancluding filter fittings and pump...just about every part had a fault ,ie.pump is bad,1 fried injector,filter clogged(when replaced seal was shot),fpr was all outta wack,egr was CLOGGED and tps was cracked..i replaced all (pump is being done as i write this....when i got the car it was running lean ,then it was running verrry rich,then it sprun a leak at the filter the one of the injectors seals went and pissed fuel all over the intake,granted they all had to be replaced as they were original parts (20 years old) i stopped blindly replacing sensors and turned it over to a professional

xdevenx

Never said I was smelling RAW fuel, the smell is coming from the tailpipe, and it is burnt fuel, excessive burnt fuel.

xdevenx

and i ohm tested the injectors, all are good.

james.gould150

does your idle go up and down when your driving?and does it backfire at all?

xdevenx

nope. no back firing, and steady rpm while driving. at idle its just rough/shaky, rpm's only move withing 100. it's basically acting like it's flooding, but the computer says its lean. all this started with me disconnecting the ecm, i have a backup, gonna try that and hope that thats it and not the prom.

Street Lethal

iTrader: (16)

How is that possible? ECM is reading a lean condition, while you claim excessive fuel in the exhaust. That would mean either you cannot tell a rich condition from a lean one from the exhaust smell, or your O2 sensor is bad. What is your fuel pressure, and how do the plugs look....?

xdevenx

I haven't checked the plugs, or hooked up a pressure gauge, haven't had the time. I do know what a rich mixture smells like. Computers are not infallible, and my o2 sensor is good. Like I said in the beginning, this problem didn't present itself until I installed, and uninstalled a jet chip. I'm leaning toward damage to the ecm.

james.gould150

any luck with the computer?

Street Lethal

iTrader: (16)

Well then, what the plugs literally look like, and what the fuel pressure actually is, these things will tell you if you are running rich or not, and not what you think you smell. You just said that this started to happen after you installed the Jet Chip. This is what you yourself claimed when you started this thread....;

What exactly are you saying here, that it only started to run rough after you installed the airfoil? Did you remove the airfoil to see if it went back to normal yet, or did you put it back on? Are you aware of just how much cfm an airfoil adds to a 48mm throttle body? Stock is 660-cfm, and airfoil brings it over 700-cfm. Now, you added an airfoil, and your BLM's suddenly went UP (lean, obviously), the engine started to run rough, and yet your sitting there telling me you were running rich because of that? How does that make sense to you?

Edit: What is the part number on that Stage 1 JET chip by the way?

xdevenx

havent really been running the car long enough in its current state to be able to tell anything on the plugs. As far as what i "think" i smell, ive been working on carb'd cars for most of my life, i know what a rich condition smells like. The JET chip was uninstalled 24 hours after install. That is when the problem started. I installed the airfoil after the chip was taken out, didn't improve or worsen condition, it was removed 2 days later.
As i've learned in the past, if you change/upgrade parts, and a problem presents itself, returning to previous configuration is the only way to determine the problem.
I have smoke tested the car and found no vacuum leaks, ohm tested my new bosch III's and found that all are good. I haven't been able to check fuel pressure.

old z mzn

iTrader: (1)

my header flanges were leaking just a little causing the blms to go crazy...couldn't hear them....had them resurfaced problem went away...off brand new o2s will sometimes do this

james.gould150

i think he may be right id try testing puel pressure its kind of pointing towards a faulty fuel pressure regulator or a slight clog in the fuel line somewhere that only affects low rpms (idle) ... just some thoughts maybe worth looking into? good luck i hope you get her runing right

xdevenx

i am gonna test the pressure, first thing im gonna do is swap ecm's and see what that does. partial blockage in the fuel line or sudden drop in pressure just seems way too coincidental, like i said, it all started when i started messing with the ecm. that is the central event surrounding this problem. if that doesnt work, i'll proceed from there

james.gould150

i only suggets the fuel lines and or regulator because it happened to me once before, might not be the cause only from what youve said about the ecm and the car being fine pre-jetchip...itd be nice if it was just that because ecms are sh!tty expensive but as i said and ill keep saying good luck with you car,its refreshing to see people taking interest in these cars to stay on the road,mine was just slavageable from the previous owner who just liked to do burnouts and didnt like to properly fix things

xdevenx

swapped ecm, running like a dream now. very slight miss at idle, but its 100 percent better than it was.

bobbyk3lly

i need an ecm for mine then im thinking, idk if it went bad or what but my car runs right when it wants and shitty when it wants,