Was doing some tuning, hit the rev limiter during a pull. Just on 23psi. Nothing major.. then on the way back to the pits, some time a slight lean condition started. Pull went very smooth, 11.5-11.6 afr, nice and clean.

It was a good one point leaner, then gradually got worse, now I drove the car home 45min, and by the time I got home the car would barley idle 17.5:1 AFR. It was... 13.5 normally, and around 15:1 it missfires slightly.

Im unsure what is causing this,

I did check the injector clips after the pull when it started to get a tad lean and noticed on the lead clips 2 of the wires were 'half out' I pulled on them and they popped out of the connector, I clipped them back in properly. Seems to be a factory thing.

The issue is NOT a dead cylinder(s), certain area's where the fuel map was richer, the car runs fine, its just a tad leaner. Mainly effected at low pullswidth area's, idle, and light cruise. Once i get into an area mid accel, it runs perfectly smooth onces the afr's dip to the 14s, however there are less of these area's since everything is graudally leaning out.

So, Its FIC 2150s, Dual fullblown walbro kit, -8 feed, -6 return. Aeromotive regulator, and a 100 micron fuel filter I believe, Its a paper filter. Fuel is 114 unleaded.

Possible pumps failing? Very clogged filter? Or bad injector?

Vacuum is good, oil pressure good, nothing in catchcan, everything mechanically looks fine. At first it was a intermittent issue, like.. rough idle, lean AFR, I blip the throttle it would fall back to idle.. idle fine at 13.5 afr, then slowly go back lean and run rough.

AEM EMS, I loaded a cal from the previous day, with minor changes, same problem.

Any pointers would be good, just where to start, what to look for. Im sure lots of you guys have seen more issues, and done more troubleshooting then I have.

Thanks. Was trying to get ready for a race Sunday,

 

something clogging the injectors? my car had a similar issue, and crap was building up in the screens

 

did you check voltage at pumps? maybe bad ground? coule be something stupid. how did the tank look when you put the pumps in? ive seen the pump sock clog and cause a issue.

im sure you checked Fuelpressure and for leaks. also ive seen a busted line on 1 walbro cause issues.

 

IIRC there was a few people around the 1st outlaw race that had a similar issue where the car didnt have 12 volts. can you go back look at the log and seecharging system voltage?

can you log fuel pressure also?

 

I pulled the pumps, both were fine, the 'bags' had a slight bit of crap on them, so I changed them out for some fresh ones. The fuel filter was spotless.. Its still fairly new too.

Voltage running is a steady 12.9, and off is 12.4.

I wasn't logging any voltage, I should have been, and unfortunatley I can't log fuel pressure. I now know that I NEED to, rather then hoping its where it should be, I need to know that it is.

Again, it isn't a misfire or anything like that. Well.. its more of a lean condition causing poor running, and its only at low pulsewidth. Other area's where its higher pulsewidth it just runs leaner but still smoothly.

I started it up, It starts up pefectly fine, Idles about 13:1 where it should. After a min or so if I blip the throttle it revs fine and then when the rpm falls it will decide to go leaner around 15.5:1 which is too low of a pulsewidth for the 2150s and it runs rough.. as time goes on the 15.1:1 turns into 16:1 then 16.5:1 etc...

Id rather break a tcase or an axle or something at the track! Haha, atleast then its obvious what needs to be replaced, this is just a pain.

Latency values for the injectors are the ones provided to me by FIC.

Im going to inspect/disassemble the Aeromotive FPR, perhaps the diaphram is leaking, who knows, there might be an issue with it.

 

are all of your sensors reading good? ait,coolant,map.


what is you base pressure at?

can you check to make sure all injectors are firing?

 

All other sensors reading fine, my base pressure is 45. The reg looks good, pulled it apart, diaphram is fine, ball/seat look to be good. All injectors are firing, If I pull one for a second at idle the car noticably runs rougher.

I have some pte 1000s I could install, it would require me adding the resistor box back, as well as re-wiring all my old pigtails. Ill look over a few other things first, then Ill swap them out.

 

try pulling each one. maybe there one not getting signal/bad?

has the voltage always been that low?

 

Check inj pulsewidth as it's getting leaner and see if the pw is the same. Maybe there's a comp of some sort in the ecu you're missing. If that's it, you'll see the pw getting smaller as it gets leaner.

 

Thanks,

Tony, I did a quick log just now. I was thinking about doing this today at work what you mentioned.

AFR is 12.9-13.0 when I start it, the injectors idle fine up to about 13.5. Pulsewidth is 1505, I let it idle for maybe 15 seconds. Then I blip the throttle and it comes back down, the AFR sits around 14.5ish, its jumpy a bit more, and the car idles rough. Now the pulsewidth is showing 1435.

I didn't let the car continue to warm up as it gets leaner.

Any insight? I guess I need to look though the comp maps. Its strange its never ever done this before, until now.

Thanks, I have the log file in AEM as well, perhaps I could email it to you and you could check it out if you wouldn't mind having a look? I logged many various things.

Just trying to get back out and do some racing!

 

Heres a screenshot of a log. Top is AFR, bottom two are engine speed/engine load. Nothing major changes, you can see where I blip the throttle.

Injector 1 PW is also on there, its hard to see. However, it has a direct change which is effecting the AFR.



Any suggestions on where I should check in my cal? Anyone willing to help with AEM experience, I can email you my .cal file, as well as the log if interesting

 

has the car been completely tuned? is it that its fine under start up enrichment, and leans out to what the map is actually set at? not sure, never tuned AEM

 

Email me the log and the file. T1race@gmail.com

 

hey any update to this, i'm having same issue but on s300 and fully tuned..

 

I can tell you I sent my injectors out to be cleaned, and never had this issue again once I fixed my clog issue

 

The issue here is that he was running a mix of race fuel and pump fuel, and the race fuel had MTBE in it. As the MTBE content changed, it was affecting the injector's flow rate.

 

I though they claimed the FIC's were MTBE compatible

 

Nah, they just follow whatever we say. lol

 

nice. I need to call you about fuel pump solutions. I found the limit of my A-1000

 

Nice! I've got the fix in stock, give me a call.

 

hmmm so i am wondering if i may have this same issue, my c16 has lost some of its properties, causing this? never has been mixed with pump gas though always stored in th vp container just in my trailor which gets 100000 degrees in it.

 

This only applies to this particular injector and C16 does not have MTBE in it. I don't know anything about your problem specifically, but it is not the same regardless if you're using C16.