i have an 99 coupe with a b18b swap. nothing hacked together. when i drive it with a steady throttle it seems to choke up a little..like if im doin 5omph it hangs around 3k rpms or so and it chokes up a lil bit when i am drivin. i first gave it a tune up..plus dizzy cap dizzy rotor and still nothin..then i changed the intake mani cuz i thought possibly it had a vacuum leak but its still doin it..my grounds are good and tight so idk what else to try??? please help ht!!!

 

i changed my fuel filter as well..and im running a stock p75 ecu. all my fuses are good main relay was changed a couple months go..what do i do next??

 

First of all this can be a lot of things...any CELs?

What is your distributor timing set at? sounds off
Fuel filter?
Plug gap?

To me sounds like a spark related problem

 

try calibrating your tps, it can be off.

 

TPS being out of adjustment would cause the car to really display effects everywhere...not sure if the OP is experiencing this...rather only hesitation at a certain RPM. Just from what I have witnessed, the TPS causes a lot more problems then just at 50 mph

 

yea your right, but my tps has bin off before and my car would just start to hesitate and sputter if you left it at a steady rpm for a while, like cruising at 50mph.

 

http://www.preludeonline.com/f61/eff...ut-tps-128426/

^^You will still be able to drive without a TPS, though not very well.
The ECU will see a lean condition from the o2 once to open the throttle and it will atempt to richen it up. The ECU will also know how much vacuum your are pulling by the MAP sensor and will adjust fuel and ignition acordingly.
You can still drive, but dont expect to set any 1/4 records and your catalytic converter will burn up withen a few 100 miles, possibily less. (extreme rich kills cats)

TPS could be out of adjustment...just the OP has not said anything regarding timing...and if your motor is missing, and usually I would check timing first. He could have his dizzy too advanced or retarded....but really there are a whole list of things that can cause this. Also the TPS will usually throw a code...right?

 

The dizzy is set right in the middle..im runnin obd1 ecu so my check engine light don't come on for much..right now its not on..it breaks up the worst around 3k rpm and over..feels like its got a load on it like its pulling a damn trailer lol

 

It ran fine then jus one day starting doin it.

 

Well obviously that one day something broke or something. That would be the place I would start looking at...what was I doing to the car that day...i.e reving high, driving fast. Not much here to work on studder problems without CELs can be a pain. What is the compression numbers for the motor as it stands...or at least mileage.

 

There are two places when the car uses the oxygen sensor. When the car is cold and when you use light throttle to cruise.

I say your oxygen sensor is faulty and needs to be changed. They are cheap enough and worth a try.

And no a dodgy sensor sometimes will not always throw a cel code.

 

bumpp motors got low miles like 83k compressions fine..ive been drivin it as is for a couple weeks just babying it but im tired of it acting up i jus want it fixed but idk what it is

 

my car kinda has the same problem, only thing my car first started jerking or surging and it just died out.........tried to crank it over and it wouldnt start.....any info?

 

Having similar issues ..looking around for answers..any luck with it?