Ok I bought some one elses project and now im paying for it. Ok the car is a 91 CRX hf with a d16z6 swap. The car runs just as im stating. It starts up great, the idiol surges around 1500-2000rpm. When you rev it up it spudders from 2000-4000ish, than opens up past 4200 like nothing is wrong. It has the xenocron obd1 jumper, 4 wire o2 sen. I read all the internet instructions for this harness double checked map sensor and all that stuff. I also did a tune up, cap, rotor, wires, plugs. Still same thing. I also know my Vtec pressure switch had low resistance when I checked it compared to my buddys d15. I didn't think that would effect the low rpm problem. Im kinda new to hondas and lost at this point any other help would be great

 

any check engine light codes popping up?

the idle is most likely to do with either a slight vacuum leak, or a dirty iacv. it could also be a fitv issue if your throttle body is so equipped.

 

what
ecu

 

x2 i had the same problem and cleaning it up did marvels

 

is your mechanical timing set properly?

 

Im running a p28 ecu and the only code it flashes is 22. Which i've already established the pressure switch was bad. Would that effect the 2000-4000 rpm spudder.

 

i too had this problem, it would spudder in the low rpms and then after 3k it would rev normal....and now that I swapped the single cam and put a b16, im having the same problem!

do u think it can be the fuel filter? It feels like its lacking fuel

 

It's more than likely you have a bad sensor. If you're car holds idol when you turn it on, the filter isn't that clogged. I would take it to a pro ricer shop in your area, or do it yourself at a schucks with a diagnostic.

Just to make sure, you did change the fuel pump when you did the swap, right?...

 

Hate to break your spirits bud, but you could have more than just faulty wiring. It's not a guarantee, but there's a distinct possibilty you have a dying fuel pump. I would get the main brains of the vehicle checked out first by a local specialist, but if that fails, highly consider changing out the pump if you haven't already....

 

how did you get the codes out of that p28 in your rex?

 

there are sometimes wires marked on the ecu jumper that you cross to get the codes to flash. if not then jump the hanging 2 prong connector on the rightside of the passenger side footwell. the cel will flash on your cluster to indicate the codes. i believe on the 88-89 chassis the service connector is located in the engine bay near the passenger side shock tower.