93LSivic

Ok, I'm not turbo yet but this should hold truth for any kind of setup. \
Today I was at my uncles repair shop. I believe that my O2 sensor had gone bad again after I just replaced it with a generic about 3 months ago. We hooked up his Snap-on scanner and read all the sensors in the car. Unfortunately since its a problem with the O2, the ECU is being lazy with throwing a check engine light. I know this is the problem cause the car was doing the same exact thing before I replaced the O2. Full rich on the A/F meter, stuttering until WOT, falling on its face, seeming like the ignition is being retarded by 20 degrees. Anyhow, we were sitting there messing with the motor runnin. Found out the O2 is acting weird (obviously, going from .01 V to .99 V.
I shut the motor down and he pulled out his infrared temperature gun. Read the temps on each exhaust runner on the manifold and found that the #1 cylinger was like 550 degrees as apposed to the rest being in the 225-250 range. He said the reason for this was that #1 was running super lean, wehre the rest were fine and this is why it fawked up the sensor. I was like no problem, I'll just raise the static fuel pressure on the B&M regulator--easy fix, maybe.
Well, we came to the decision that sice the #1 cylinder was the furthest from the fuel feed on the rail so it was being starved for fuel, thus running lean. After we noticed that, we started the motor up again ran it at 4K RPM for a minute or so to get the headers nice and hot. Sure enough #1 was up at 500+ degrees and going down the line (#2,3,4) the temp decreased for each cyliner. Now, I've noticed that a lot of times people blow the #1 cylinder in F/I applications---could this be why??
TO remedy this. What I've seen on many performance cars is that they will take a fuel rail and tap the fuel feed into the middle--obviously so fuel pressure would get to each injector equally. This should fix the problem.

What are your guys ideas on this?? Or is my #1 just F'd up--maybe an injector thats losing its flow rate?

SEFIxCivic

from my experience on high hp apps, cylinder three is usually first to go.

1fstevo

I think pressure in the fuel rail will let all four injectors spray equally if injectors were fine. Fuel flows but it is also pressurized if you think about it. If you are not FI and still run lean on #1, then I think you should check your injectors. Most FI blow the #1 cyclinder is probably due to Drag manifold since the waste gate run off the #1 runner which Air flow goes quicker on that paricular cyclinder and cause lean.


[Modified by [Evo]Hybrid, 8:12 AM 2/1/2002]

boosted3g

The fuel rail issue does have some truth to it. I remember back in the day with my MR2 i picked up over 20 hp just by replacing my fuel rail with a dual feed rail from Alamo. I dont think its and issue now because of so many manufactures making huge fuel rails.

b18bturbo

cylinder 3 is the first to go most of the times. Its never the #1 unless you drop some valves or something.

Dublocivic

Number 3 usually goes first because it runs the hottest. *Trick* (by having the #3 injector calibrated to flow about 5%or more (depending on EGT's) fuel at the same fuel pressures will cool #3 to what the corresponding cyls run at for EGT's) This will help remedy the #3 prob.

98hx99b18c

#3 due to the cooling by the head

dbman96

I think if the #1 cyl is running lean the fuel rail issue may be a potential problem but only if your fuel pump is completely maxed out. This shouldn't be the case in a N/A car like you're describing - you could however have a clogged injector. I would consider swapping injectors between different runners and see if the problem follows the injector.

falcongsr

definitely sounds like his #1 is starved for fuel. you beat me to it.

93LSivic

Ok, found this on a DSM site. Seems to be helpful. Some good reading!
http://www.stevetek.com/R-FuelSys.html

Actually I will just start a new thread. This seems to be helpful for guys looking to totally redo their fuel system.


[Modified by 93LSivic, 7:06 PM 2/4/2002]