BAD HESITATION!!!

Basic tech questions such as future setups, different turbo kits, car diagnosis, etc
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robsterzallan
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BAD HESITATION!!!

Post by robsterzallan »

i want to turbo my KA really bad, but its got a terrible hesitation. when you step on it it falls on its face. but if you ease on the gas it will redline. idles great, fuel pressure is at 42 psi, ive tried everything. anyone else have a simaler problem???
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broken40s
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Post by broken40s »

cam timing? when i first got my s14, the exhaust cam was advanced 2 teeth. idled ok, but couldnt slam on the gas at all. throwin any codes?
95 240, nothing special
robsterzallan
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Post by robsterzallan »

Not throwin codes that my obd2 can read, but it does blink randomly when im driving. cam timing isent off any teeth just checked, and put my ignition at TDC with throttle unpluged, pluged it back in and the ecu put it where its supposed to be at 15 before top dead. im gonna freak out lol its been doing this since i got it.
robsterzallan
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Post by robsterzallan »

Alright, heres a better idea of what we are working with.
Heres what ive done to it..
Solid motor mounts,
stage 2 clutch
light weight flywheel
new stock pistons and rings
arp head studs
new head gasket
new crank (spun a bearing)
full timing kit(stock)
cold air intake
plugs and wires
ebay cat back
throttle body spacer
deleted my egr with plate
areomotive fpr
fuel filter
O2 sensors(broke them again i think)
relocated the fuse box to dash,batery in the trunk

Okay, so since all of this it hessitates. when you step on it (putting it under load) it falls on its face. if your rev easy, (foot where the tach is) it will redline no prob. My plugs are white, fpr is at 42psi. when i set the timing perfect at 20 BTDC it idles amazing but any gas and itll shut off and wont start untill you advance it. so now im running like 35-40 BTDC so it will run right. all internal timing is dead on, checked 85 times plus 2. and when i put it on time its retarded. to ad to that, i had nistune in it but took it out trying to get the car back to stock so its easyer to work with. anyone else ever have this? what f**king sensors could be telling the computer to do this to the poor KA. I really need to turbo it and im not even thinking bout pulling the motor untill its 100%. to add to that, ive had EVERYTHING apart, down to the block. im not sure if deleting the egr and carbon canister could of thrown me off vacuume lines, but i only got 1 line to my fpr, and one going to the bottom of my throttle. everything else has a cap on it. PCV valve could be in fault as i do not kknow what to do with it. could be anything. been workin on it forever. im going on a family vacation sat. Thanks everyone so so much
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Post by NateDogg »

Sounds like a possible vacuum leak. White plugs means lean (too much air).

How much vacuum do you get at idle?

Are you back on the stock ECU with no daughterboard?

I would rather have Nistune on and watch the Nissan Data Scan to see what the sensors are saying.

Your timing sounds really suspicious. Setting cam timing on these motors is a bi*ch so you may just be looking at it the wrong way.
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robsterzallan
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Post by robsterzallan »

Not sure. ill hook up a vacuume gauge today and see. but no im positive timing is dead on. i was told to get it to stock by a 240 guy, and work from there. but yea the daughter board is out. and the engine light just blinks. when nistune catches it it says O2 sensor. but vacuume is deff. a possibility since ive messed with all the vacuume components so much. NO IDEA its really getting to me. im close to pulling the motor to the block again, and checking ALL sensors, and all messurements before i put it together again. i put a degree wheel on the bi*ch with a dial on the piston so i know timing is on.
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Jmcc
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Post by Jmcc »

timing ain't to bad in this motor. but are you sure you rotor is match to the cas on
#1 tdc? i havn't had eny body mess that up yet but just a thought?
robsterzallan
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Post by robsterzallan »

So heres the update. i HAVE to have injector #3 leaking, its spraying fuel like non other and wont even fire. the cyllinder is dead as of now. ill fix that in 10 min. but i checked my valve lash, and compression. heres what i got
FRONT
.015 .013
Comp. 143psi
.017 .012


.017 .012
Comp. 140psi
.016 .017


.015 .015
Comp. 160psi
.015 .013


.014 .016
Comp. 150psi
.008 .016
REAR

FSM says valve lash should be .013 to .016 meaning only cylinder number 3 is in spec, and it has the highest comp. So saying that, valve lash and valves are leaking possibly. Anyone know what spacers can be moved to where to put them all in spec? and timing is on.. i promis. it wont run unless timing is way advanced.
robsterzallan
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Post by robsterzallan »

UPDATE
So i set my lash, but checking spacer thicknesses and moving them around. i doubt this was an issue but its nice to know they are right. so the lash is set. i do see im gonna have to save up for a valve job before i turbo it, but thats ok. still back to the main concern. i cant figure it out, timing is set internally, i just had to set it again since the cams were out. but if its on correct ignition timing, it wont run. but soon as you advance it its fine. :wtf: i moved here from 240sxforums.com in hope you guys knew whats goin on. i can see the knowledge here is much better already.
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supakat
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Post by supakat »

How can we diagnose a car we don't see in person? Most issues are people don't know how to define the issue, explain the issue, or leave out important factors. Granted some things are easy when you tell them but ish like this could be a billion and one things.

Did you replace your cap, rotor, or wires?
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robsterzallan
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Post by robsterzallan »

cmon guys i hate replys like that.. use the search button.. and stuff like that. all you gotta do is ask:) but yes.. rotors fine, new plugs and wires. ive exlpained basicly everything else i ould
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supakat
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Post by supakat »

I am just saying cuz you jumped over here from 240 forum. check your tps. Read the fsm to know its values.
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robsterzallan
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Post by robsterzallan »

already did, .5 at idle, 10 wide open, yes its in check. this problem is gonna kill me
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supakat
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Post by supakat »

I thought tps were 5 volts. .45 closed and 5 open. Please enlighten me.
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robsterzallan
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Post by robsterzallan »

no its close to nothing at idle and the more you open it the higher the resitance all the way to ten i do believe
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cleantune
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Post by cleantune »

robsterzallan wrote:Alright, heres a better idea of what we are working with.
Heres what ive done to it..
Solid motor mounts,
stage 2 clutch
light weight flywheel
new stock pistons and rings
arp head studs
new head gasket
new crank (spun a bearing)
full timing kit(stock)
cold air intake
plugs and wires
ebay cat back
throttle body spacer
deleted my egr with plate
areomotive fpr
fuel filter
O2 sensors(broke them again i think)
relocated the fuse box to dash,batery in the trunk

Okay, so since all of this it hessitates. when you step on it (putting it under load) it falls on its face. if your rev easy, (foot where the tach is) it will redline no prob. My plugs are white, fpr is at 42psi. when i set the timing perfect at 20 BTDC it idles amazing but any gas and itll shut off and wont start untill you advance it. so now im running like 35-40 BTDC so it will run right. all internal timing is dead on, checked 85 times plus 2. and when i put it on time its retarded. to ad to that, i had nistune in it but took it out trying to get the car back to stock so its easyer to work with. anyone else ever have this? what f**king sensors could be telling the computer to do this to the poor KA. I really need to turbo it and im not even thinking bout pulling the motor untill its 100%. to add to that, ive had EVERYTHING apart, down to the block. im not sure if deleting the egr and carbon canister could of thrown me off vacuume lines, but i only got 1 line to my fpr, and one going to the bottom of my throttle. everything else has a cap on it. PCV valve could be in fault as i do not kknow what to do with it. could be anything. been workin on it forever. im going on a family vacation sat. Thanks everyone so so much
So..timing is done. Replaced cap, rotor, wires. Checked lash and compression. Fuel pressure is ok (just under idle?).

Please forgive me if I am asking things that have been said, but I just wanted to clarify, if nothing else. So you have already replaced the fuel filter? What spark plugs are you using? What are they gapped to?

When you are driving down the road does the engine act normal under light throttle, but then as soon as you quickly go WOT it falls on its face? Have you checked out the MAF? Is the intake an oil filter type or dry?
robsterzallan
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Post by robsterzallan »

yup all that was replaced. im using stock NGK plugs, regapped to stock spec i forget what that is i believe its .40-.45 or something. and new fuel filter. and yes its perfect under normal throttle but WOT it hessitates extremely untill you let off, and its dry, been on and ran fine before the issue. MAF is new as well
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cleantune
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Post by cleantune »

robsterzallan wrote:yup all that was replaced. im using stock NGK plugs, regapped to stock spec i forget what that is i believe its .40-.45 or something. and new fuel filter. and yes its perfect under normal throttle but WOT it hessitates extremely untill you let off, and its dry, been on and ran fine before the issue. MAF is new as well
Do you still have a catalytic converter? Just to further narrow the possible problems: how old/ what octane gas are you running? If the gas has been sitting for a while it can attract water, lowering the octane rating on it. Stabil automotive fuel stabilizer works great to correct this problem IMO.

My appologies if I missed this, but did you say that the car was currently running on a daughterboard tune? (if so have you tried the stock ECU?... again please forgive me if this was already mentioned).

I asked about the filter because we put an oiled filter intake kit on an Rx8 and it sucked, fine under acceleration, but fell on its face under WOT. Maf was covered in oil.
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Post by joe62890 »

Check your knock sensor for cracks. Could be that the knock sensor is reading false knock at WOT and causing the timing to retard severly.
robsterzallan
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Post by robsterzallan »

no cat, and knock sensors brand new. not throwing codes accept for TPS, which tested good, i have a OBD1 TPS, will it work on a OBD2 ECU? now it wont start, no spark. what ECUS will work on a 95 KA24DE OBD2 car?
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Post by blacks13coupe »

Any updates?
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