i recently got my ls/vtec into my 91dx, did the whole mpfi business as per the good instructions by fourthgenghatch anyway, i've been having issues with it running right, and i'm looking for some help.

when i first start the car it fires up nice, revs to about 2000rpm, then the revs drop and it dies. i can keep it going if i give it a bit of gas, but it also bogs at the first bit of throttle, then revs up when i let off. i've checked all the tps, white wire business and thats all fine.

what i have discovered though is that if i pinch the fuel return line, my idle rises up nice, and i have way better throttle response, almost no bog at all. what would you guys think.... reg gone bad or stock dx pump giving up? the fuel filter is new, inj work, proper resistance, i can hear the pump prime up etc...

i do have a chipped(mugen) pr3 ecu, it seems to run very rich at first, it dumps lots of fuel at startup, but has lots of trouble with hesitation and bogging, and the a/f meter goes to lean after a while of running.

 

im having similar problems. I have a 88 crx dx and let the car sit. Changed fuel filter, no change.

When i gas it and try to drive, it dies.

 

help us

 

i did some research and it could be fuel issues.
Detonation, bad timing etc.

Its going to a hassle, but ill fix it

 

any codes? If not maybee a vacuum issue.

 

nope no codes at all, i'm pretty sure its not a vacuum issue.

 

CHECK FOR FUEL PROBLEMS...FILTER CLOGGED, OR PUMP SHORTING OUT...NEED TO UP YOUR FUEL DELIVERY!

 

just bumping for more input. it seems like lots of people have these bog/hesitation issues, but haven't solved them yet. and if they have they don't like to write it in their post... argh

 

i havent solved mine yet and im hoping its not a pump problem.

There might be condensation in the dizzy cap so il check that out (cars been sittting in the winter/cold)

and ill check my plugs

and timing

 

yep still have mine
i think i will solve it by this monday taking it to the dyno hopfully they can figure it out cuz my builder can't....

and this is pissing my off
i floor it and it boggs at 5000 and if i let off it goes slowly up passed these rpms

i upgraded everything
i hope it ain'y the dizzy cuz i have another but it does the same **** with that one
hopefully something needs to be tuned

if not will post if i fix it maybe u guys have the same prob

 

let us know for sure. i'm gonna test my fuel pressure tommorow and see what its at.

 

maybe the ecu was chipped incorectly , seen that before chipped for p28 instead of pr3

I would get hondata

I lvoe mine

smooth curves man

 

its possible, i got the chips from hyperducktuning, he gave me two diff mugen proggy and a mines. they all seem to make it run the same.

today i made some headway i stuck a diff set of inj in and it ran well no stalling etc..., it still has a slight hesitation off idle that i have to get rid of.

my mugen proggy has a vtec engagement of 3800, but reving to 3800 w/no load does not engage the vtec... it starts to hesitate around there as well.

 

i was thinking it may be injectors... i think ill swap mine.

my gas may be crappy but i added methyl hydrate, 6 bottles of water remover, i bottle of injector cleaner and it still bogs/wants to stall.. it seems something is definately clogged. (car was sitting for 3 motnhs of cold with less than 1/2 tank)

i checked my plugs and under the dizzy cap and no moisture
changed the oil too...

 

i took mine out and cleaned them by opening up the injector with a little voltage and shooting some cleaner through them w/air. they were a little better, but not very good. i have to pick myself up a set.

see if one of you buds will loan you their injectors, thats what i did, it will save you some cash if thats not the problem.

 

Try switching around the two outside wires on your TPS. Mine were backwards and it bogged hard off the line then would go.

 

where the tps located?

Well my cars an 88 so i thought that i might as well pick up some used injectors
and a fuel pressure regulator and walbro fuel pump off ebay

AFter i put those in ill inform you all again.

i hope its not the lines that are clogged

 

the tps is mounted on the throttle body.

be careful with ebay used injectors, my bud just got a set of those and they were no good. try to buy local if you can, that way if they are no good you can at least do something about it.

let us know how it goes

 

im actualy picking up the injectors local and i found a 190lph walbro fuel pump from honda tech.... ill get the fpr fromebay since thats the lowest price so far...

ill keep ya posted

 

i think its because my car sat a while, there was crud in my engine block so thats what may have caused the idle.

 

Check the fuel pressure because if the fuel pressure get up when you pinch the return line it's because your fuel pressure regulator is not keeping up the pressure. So your problem must be in the fuel pressure if you have a adjustable fuel pressure regulator well adjust the pressure to the good one.

 

my cars running fine now

drove it around and it was awesome to get her going.

all i did was let the car run everyday and after the 3rd day it started to run normal again

 

wow that is weird i
tried that also

about the fuel line thing

but weird since i got everything upgraded

what u think i can do

and can a 02 sensor have something to do with this???

like not having one plugged in????

i doubt that

right??????

 

MAke sure you guys a frequently changing oil during break in period.. for LS vtecs it helps alot towards getting a better idle.. and flush out your coolant...

 

cars starting to do it again and put putting on idle

can it be a bad alternator?

or mainly air/fuel issues?

i need to figure it out!