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Discussion Starter #1
So now my car hesitates under boost, down low it hesitates (still pulling) but then it pulls really hard to about 4000rpm falls off until about 5000rpm then pulls strong the rest of they way. New plugs/wires gapped properly. The plugs I removed showed a small amount of incorrect heat range it seemed? Coil pack test fine along with the maf, tps and the isa. Timing belt seemed fine as well. Im running 8psi (with this hesitation) but I always ran 10psi before and it just doesnt have the power it used to (not awhole lot faster than 8psi). I ran a pressure test on the intake system their are NO boost leaks. Im going to change the fuel filter this week just in case thats posing a problem. Any other ideas? Im also going to do a compression test to make sure thats not FUBAR lol When I ran 10psi before the engine wasnt quite up to par (trouble codes and such). Now everything is up to par and working great (I believe). Now I have the hesitation. Im running the same fuel pressure and everything... Maybe I just really need a safc now that its running as it should and the richness is causing hesitation? Im getting a safc for x-mas hopefully.... Just wanted some thoughts, maybe I overlooked checking something. Thanks for any help,
shawn
 

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What did you change that can affect the change from before until now?

Intercooler? Piping? BOV? FPR? Injectors? Computer?

You really should post all of this under one topic that you already have. like "Boost problems"

I wish I could help. My car is stalling when I first touch the throttle. After that power builds until shifts.
 

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Discussion Starter #4
LOL No I dont think I toasted a piston ring, even if I did its not that big of a deal, I will just swap to the other built motor I have.... The can runs fabulous.... I will post up a compression test results this week....
 

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just because its running pretty good doesnt mean you didnt toast something. my d15a7 ran "fine" for weeks on a cracked ring land (cyl 3), it just had slight hesitation at certain rpms and throttle and loads. the joys of having the water inj bottle empty and not knowing.
 

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Discussion Starter #6
Im going to go outside now and run a higher pressure test on my intake system than last time. Its kinda running like it has another leak, I'll find out. If not Im still doing the compression test this week sometime.
 

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i'm sort of at the same spot as well, severe hesitation randomly under light loads. i had spent 4 hours last night under my dash convinced it was an electrical problem. but this morning on the ride to work i was remembering that this happened a few times when i first put this setup together. it was spark plugs. this last change (about 3 or 4 weeks ago) i attempted to use two heat range cooler plugs. it seems they have fouled or dirtied 10x faster. ; so i'm going to invest $8 tonight and spend 20 minutes changing plugs back to SCoupe Turbo heat range. i'll keep ya posted as internet in the new house is limited depending on wind conditions and cloud coverage :: h4X0r ::
 

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Discussion Starter #8
Well I went over a few more things. With the boost controller off the turbo still overboost badly. I still need to do another pressure test but I did the last one 6 days ago and when I finished I had no leaks. With the boost controller on trying to run 10psi I cant do it, the car hesistates and even bucks sometimes. Seems worse when the motor is cold. I pulled my plugs out to give them a read. They show too hot and/or lean. I've been rich all along , now Im lean ? Or my plugs are the wrong heat range (one stage colder). I just got in the mail today my 2 stage colder plugs so I will give them a shot, hopefully the same thing that happened with yours jason dont happen with mine. I going to do another pressure test on the intake and do a compression test this coming weekend to see whats going on. Im also going to change the fuel filter, that might help me out.
 

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hey, so i changed out the 3922 plugs last night (two heat range coolers) and they were black black black. they've only been in the car maybe 3 weeks, and the car was driven daily for about a week and a half. i switched to 3923 plugs (scoupe turbo) car runs a lot smoother now but it still has a random hesitation. i've got a check engine light so i'm going to try to get that scanned tonight to see if it's like a TPS or something. i'll try to keep you posted. it may be a different issue but maybe we can help each other. my fuel filter was replaced about two months ago.

my next large project is going to be to replace the exhaust manifold w/ something nice looking (maybe that offer in the FI forum, X3 semi equal length) and to figure out the damn hyundai pcv system... my breather filter on the valve cover is caked in oil... pressure from the turbo in the valve cover maybe?
 

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Discussion Starter #10
I using part # 3923 in the car currently. Do you still have the pcv valve attached to the intake manifold and a breath filter to the right of the pcv? My breather filter hasnt really got dirty, I dont think you should have that much blowby. Mine is setup the same way I just listed. I want another manifold as well. I have a built 1.5 in the shed Im about ready to put it the car (even though its uncomplete I could always go back and swap the head later).
 

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Discussion Starter #11
So I installed two stage colder plugs today and ran a compression test which came back acceptable. Im at a loss. I also swapped to another MAF sensor I had. The power is VERY uneven and only at WOT! Could a fuel filter be causing this if it was hindering the pressure (though i have a walbro 255)? I am going to replace it just to see.... If that doesnt solve it I have no clue I've been through almost everything... Maybe the strainer on the fuel pump , which I cleaned very well when I changed... I dunno.
 

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Discussion Starter #12
Well I got the cel scanned again today, as it ran better but far from pefect... I still have the CEL of doom P1127 Air fuel metering longtrim rich condition. So I am experiencing firsthand the ecu cutting fuel over and over again... Definitely time for a piggyback =-)
 

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hey! merry christmas.

i've been slightly beating on my car. every now and then when we can't communicate (me and my baby) our relationship gets rough. lol but i have a difficult time putting my foot on the pedal more than 50% (as the SAFC shows) don't really need to, but i'm also scared to blow a charge pipe off or break something major as it is cold here now and very wet, between the rain and snow.

i've always had the 1127 code... my sources told me it was exhaust gas too cold, second O2 bank. which is basically the same cause as what your code states... too rich. i've tried tuning my SAFC every which way over the past 2 years and to no avail. too lean, too rich, variations over RPM ranges, variations based on throttle position... do you run an FMU or a RRFPR? also, is this a cause of having an open-atomosphere BOV? :: shrugs :: i don't think so as one time i attempted leaving my wastegate disconnected for a week (no boost) and still managed to pull this code...

there is no exhaust wrap on my manifold or down pipe, and i think i may have an oil leak from the pan (stupid copper gasket maker) onto the exhaust which may possible be cooling my exhaust down? i just ordered a stock scoupe heatshield to add to the mix and see how that affects the code... also gotta get that leak fixed... i wish it wasn't so cold here and i wish i did not work 7 days a week. after all what good is all that money if you can't enjoy it... dammit...
 

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have had the same code forever and i hate it to death, it comes up every 2nd long term drive after an ecu reset, i have an 2nd o2 sensor simulator mabey we could use a 2nd o2 heater simulator also?
 

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Discussion Starter #16
My code says air fuel metering device on the scanner. Im not sure where you got exhaust not hot from? :
CODE: P1127
CODE DESCRIPTION:

Fuel Trim Multiplicative, System Too Rich

PRIMARY COMPONENT:

Air/Fuel Control System
If the air/fuel mixture under load is too rich for more than 30 seconds during two back-to-back trips, this code will be set and the Malfunction Indicator Light (MIL) will be turned on.


Details:



The code will be triggered if the following conditions are met:

Long term fuel trim value (multiplicative) is less than 0.77 ms for 30 seconds or more
Engine load is more than 2.0 ms (1.7 ms, 2.0L Tiburon)
Mass air flow rate is more than 8.4 g/s
Engine coolant temperature is greater than 158°F (70°C) [176°F (80°C), Accent]
Engine in closed loop operation
No canister purge occurring


Thats off webtech. From what I understand the ecu needs to be reset regularly with the use of the safc. You have the version 1 or 2? If you still have the code you have a rich condition (which should be fixed with the safc) or a sensor problem (one of the above). Another common cause can be the evap. canister is full. Why did you use copper gasket maker on the oil pan? The dealership calls for standard rtv sealant which is what used. Merry X-MAS !
 

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Discussion Starter #17
Alright I fixed the hesitation that was going on and misfire. My coilpack was going bad (no cel). Changed it now its much better BUT....

Under boost it seems my a/f ratio is all messed up the car misfires but its not a misfire. Like Im losing fuel..... Reset the ecu so thats not the problem. I havent tried since I changed the coil pack lower boost but Im sure it will run fine. Just at 9-10psi it does this crap... Same fuel pressure and everything as the 3 months it ran fine @ 10psi. This sucks.
 

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how are your spark plugs? gapped, etc? might be blowing out the spark. got gas? sometimes below a quarter of a tank and a high flow walbro pump, fpr will act erratic. also check any engine grounds in the bay. the problem i was having was due to a bad ground, not the coil pack.
 

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Discussion Starter #20
At the moment I have an E-manage installed. Its not really tuned, I just knocked some fuel out at idle and 2,000rpm to relieve the ecu of the too rich condition code. The tank is full (doesnt matter if its on e lol). The spark plugs are brand new (2 stages colder). The plugwires are less than 2months old MSD 8.5mm plugwires.... I have a ground kit installed (custom) under the hood.... The ground on my battery is tightened down the best, I left it loose enough to pull off constantly to reset the ecu. I doubt thats causing the problem though.... I'll tighten it anyway. I know I just need to get the E-manage tuned but Im thinking if this isnt an a/f ratio problem (which it shouldnt be as I ran this same crap for 3-4 months w/o this problem) then getting on the dyno is going to cost me 2-300 bucks and they wont be able to do nothing b/c the car will be acting crappy! On the other hand if it is just a an a/f ratio problem it will be fine... Dont want to waste the money though lol Im running 8psi with no problems right now, turn it back up and its a no go. It seems to break up under boost... Maybe it is that ground I'll play w/ it more this weekend.
 
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