Archangels

I have no idea why and i'm trying not to use curses here but, i have re-grounded EVERYTHING i possibly could have, cleaned up the factory grounds, had my injectors professionally cleaned, adjusted TPS, re-wired the ECU, basically did everything possible to get rid of my hesitation but it's STILL THERE, if i pin it in 1st gear my car does nothing but jerk and make me almost smack face off the front windsheild....

i have no idea what's left to do, i was thinking injector clips?...

if you have any idea's please let me know, it's as if the car does nothing when i pin it, then thinks "oh, ok, imma go now!" then takes off....

also, if i free revv. it in neutral it acts as if there's a revv limiter just over 5000rpm....

any idea's!?

Chuck

iTrader: (2)

You adjusted the TPS. Did you also check it's sweep? A dead spot in the sweep will cause problems in acceleration. After that, maybe a clogged fuel filter or clogged cats. After that, secondary actuators stuck? Sounds like its getting fuel starved when the secondaries are supposed to be kicking in.

sidewayz_FC

check the maf connection to the harness, check for pins pulled out and make sure its in the right way. good luck

sidewayz_FC

double post ownz me

Chief_MC

Have you checked your fuel pressure regulator and fuel pump? You would want to check it with a fuel pressure gauge while driving.

Archangels

TPS sweep was good, fuel filter is new, i have no cats, MAF plug is fine, brand new walbro 255lph was installed a year ago....

havent checked fuel pressure but it should be fine....

this is getting gay, going on 2years now....

it's fine if i'm under 1/2 throttle, but if i boost and actually make the car GO it does this....

i DO have an MSD6AL sitting in my bedroom ready for install, any idea's if this might help fix this stupid problem?...

ironically it seems as if the problem is intermitent, some days the car drives perfect, other days it sucks *****....

Rx7TyreBurna

iTrader: (1)

I am not turbo, but I have Walbro 255 in my N/A. Going to pressure test tomorrow. I am sure it is too high.

Considered getting an FPR?

Mine is doing this... While I am going down the road, and then press the gas, my car seems to "think for a second" and then go. I also noticed that at barely pressing the pedal, sometimes I can get it to make a weird sound and feel like it is wanting to bog.

Good luck!

NZConvertible

You know what they say about assumptions... Check the fuel pump voltage too. In fact hook the DMM up to the fuel pump connector and put the it somewhere you can see it while driving (use speaker wire to extend the wires). See if anything funny is happening to the voltage when the problem occurs. Voltage should be ~9V at idle and low load and jump up to >12V under heavy load.

The engine should be able to run perfectly fine without it. The only benefit might be that if it does make a difference you'll know the problem is ignition-related. But it won't fix it and it'll more likely do nothing.

FCKing1995

iTrader: (3)

It makes an ******* out of you for saying that? I used to get asked if I knew what they say about assumptions, daily...

RETed

What is the max TPS resistance you're seeing?


-Ted

Wankel7

When this jerk happens...does the tach needle also drop really fast...fast then it ever could ?

James

Archangels

i dont notice anything with the tach, or i should say, i havent really paid attention to it....

i am currently looking into FPR's aswell, i should throw a guage on there atleast to find out whats going on....

ahh, stupid problems like these, but it's weird, 1st gear gets all the hesitation i COULDNT want, but other gears, i pin it, hesitates for a second then goes like hell....

odd....

Archangels

** Double posts own me....

Will_s

iTrader: (7)

^ what exactly does that mean because mine did it a couple of times last month at night while doing close to full boost. Tach would turn off and all power would be gone for like a second, almost like the key was turned.

Archangels

this happened to me a few times last year too!...

Roen

iTrader: (2)

I'm having problems with hesitations as well, I've done everything mentioned above except for adjusting timing and cleaning injectors. When I'm in low rpns in first or second and off the clutch, brake and throttle completely, the car will buck forward awhile until it stalls. I set the narrow TPS at 1.0 kohm and the max reading is 4.8 ohms.

Wankel7

Not sure if this will help...I had some massive hessitations come out of the blue on my car with an e6k. Turns out the harness running from the CAS to teh E6k was getting some massive interference from the alternator. I ran the car around the block with out the alternator...and it ran great. Go figure.

The thread about it
https://www.rx7club.com/haltech-forum-62/bucking-along-tach-needle-bouncing-470609/

James

Archangels

anyone else have any idea's?...

i hear people dont need an aftermarket FPR on an S5 but at the same time, could this still be my problem?...

i'm running an S4 keg with all S5 externals like manifolds and such, would i be using the S4 rails or S5's, how can i tell the difference?...

NZConvertible

S4 or S5 makes no difference as to whether you need to upgrade the FPR.

The S4 rails are cast aluminium and the S5 ones are welded steel, but again it makes no difference. They're interchangable.

Have you tested the fuel pump voltage yet?

Archangels

is there going to be any clearance issues weither i use the S4 or S5 fuel rails with my S4 keg and S5 manifolds?...

from what i hear the S4 can be modified to adapt to an aftermarket FPR, yes?...

no i have not done the fuel pump voltage test, i cant remember if you explained how but i might have missed it....

NZConvertible

Nope.

Either can be modified but the S4's is easier. You'd have to cut the end off the S5 rail and weld a hose connection on, but with an S4 you can unscrew the FPR and screw in an adaptor.

Post #8...

Archangels

i know it will sound stupid but regardless weither i use the S4 or S5 fuel rails, they will both fit the injectors the same?...

with an S5 welding on the end wouldnt be hard at all, but how do i go abouts removing the factory FPR?...

any further information about modifying the S4 rail or S5 rail?...

i need this done asap, my car sucks....

arghx

iTrader: (3)

Can you give us a complete mod list? What emissions equipment are you using? Are you on stock injectors?

Archangels

** Stupid double posts....

Archangels

oh god, i hate typing out the whole list....

basically....

720cc's secondaries, walbro 255, HKS PFC FCON, HKS GCC, S4 keg with S5 externals, grounding kit, blah blah blah, 3" TID, RB exhaust, greddy FMIC....

it's just running dumb....