i have a Supercharged GSR that just recently started breaking up on light to partial throttle and i cant figure out what the problem is!!! heres a little history, the car ran fine for a good 5-6 months until i noticed, usually only in the morning time, the car would start to break up slightly under light loads but after warming up, the car would go back to normal. well all of the sudden, it started to get worst...now it breaks up whether it is hot or cold, and the idle has now dropped and my wideband is now reading 15-17afr's @ idle when usually it was 13-14, ive changed the spark plugs, dizzy rotor, cap is fairly new, wires are fairly new...here are the spec:

550 rc's
walbro 255
JRSC on 8 psi
4-1 header
2.5 exahust
street tuned on crome

any easy ways i can trouble shoot what the problem is? would a bad fuel pump installation cause it to do this?

 

start with vacuum leaks, then check fuel pressure also with temp changes in the air check your temp corrections, whats your a/f under boost now compared to when you didnt have any issues? and i hope you let your car reach operating temps befor eyou whip on it

what cap and rotor and wires are you running?

 

well i dont think i have any vacuum leaks but i'll double check, under boost, the AFR's seem to be fine @ around 11-12 but my clutch does slip so i dont really rag on it to much, i live in FL so temp changes arent much here...my fuel presure gauge just took a crap on me so i cant check that yet until i buy a new one, i almost always wait till my car reaches full temps before ragging on it due to vtec not engaging if i dont. im using an MSD rotor, Adavnced auto cap and Magwire wires, also, i forgot to add that i actually switched my entires dizzy out with a friend of mines and same issues...

 

did you switch the entire dizzy but still use your cap and wires? what plugs gaps are you running?

 

yea i did, but they are fairly new although they are advanced auto crap, do you think they would go out already? im using bkr7e's gapped to .32

 

i dunno i been through 2 thermostats from advance auto in 3 months. just an example of crap breakin soon.

im havin problems with a break up too, but at over half throttle. it almost dies. falls flat on its face as soon as the pedal goes down. scary. worst part, no wideband. im tapped out broke.

 

whats wierd is when i changed my rotor after trying an entirly diffrent dizzy, it actually ran fine for a day, the next day i started it up and BOOM same problem right at the start up, WTF can it be?

 

have you taken the plugs out to check the gaps. Sometimes you can lightly detonate and close the gap on your plugs. that will cause a part/throttle or idle misfire every now and then.

 

ive swapped the plugs with anther set properly gapped and still the same thing?

 

anymore ideas?? does anybody think it could be the pump??

 

bump! c'mon honda tech i need some suggestions! does this sound like an electrical issue? would the fuel pump be the cause? its a pretty quick break up and the car is really slugish on low end...

 

bump, still need some ideas! im stumped!

 

nobody? all i need are some diagnosing or troubleshooting tips!

 

I think you already answered your question. Its either a sensor or its the pump. I wouls start with the Map and TPS sensor. Get a multimeter and check the signal output voltage at different throttle positions. full throttle should be 5v and check the signal of the map with the key on engine off and it should be 5v.

 

well i swaped the map sensor for another and same thing, now my real question is, would a fuel pump cause this issue?

 

throwing any codes? mine did it for a while then showed a code 17 for injectors...turns out it was the main relay

 

bump because i am having the same problem in my boosted rsx trying to figure it out now also... if u give the gas a little more than a sliver it breaks up and dies if u keep holding... it seems like its some kind of a fuel cut

 

I had similar problem and it turned out to be my ignition coil. If you have replaced your entire dizzy, then that would not be a problem.
Fuel pump could be a problem. How old is your current one?
Get a Helms and check the wire code going into your MAP sensor. The MAP sensor and some other plug (which I can't think of) have the same connector type. If these are swapped, it will cause problems too.

 

my pump is fairly new, but i had to do some rigging cause it wasnt direct bolt in...not i fear its biting me in the butt!!! and i'd hate to drop the fuel tank again (89 crx) and find out it had nothing to do with it. im gonna check to see if the injectors are clogged