AlexGTAdv Posted March 11, 2009 Share Posted March 11, 2009 For a while now, at lowish revs in a high gear, say 4th if i put my foot down the turbo will spool up fine and boost up to 0.8 bar instantly but the car feels like its hesitating, it doesn't pick up, it makes a lot of noise but it just doesn't feel wright. I have replaced the dizzy cap, rotor arm and leads as i thought it might be a weak spark but it isn't much better. Could it be the injectors are worn out or maybe need bigger ones? Quote Link to post Share on other sites
Guest Enzo Posted March 11, 2009 Share Posted March 11, 2009 have you checked the spark plugs?the porcelin could be cracked on one of them, which would cause that, or the gaps could be out? Quote Link to post Share on other sites
AlexGTAdv Posted March 11, 2009 Author Share Posted March 11, 2009 have you checked the spark plugs?the porcelin could be cracked on one of them, which would cause that, or the gaps could be out?No i haven't. I only replaced them last year in july i think with the NGK iridium ones. Do you know wot the gap should be? Could they be worn out already? Quote Link to post Share on other sites
Guest Enzo Posted March 12, 2009 Share Posted March 12, 2009 they could easily be worn out dependant on how many miles you do, i cant remember the plug gap from memory but it would be good to get them out and have a look especialy round the porcelin for cracks Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 Took my plugs out the other day and there are no cracks on them but i did notice that they were very white and has some build up on them. I have been told that this could mean it is running lean! Could the fact it is running lean be causing the lumpy acceleration? Also i have noticed that if you accelerate on about half to three quarter throttle it is alot better than when you floor it. How can i stop it from running lean. I have got a HKS-Fcon piggyback ecu that i haven't fitted yet, would this sort it out if i put it in? Oh yeah and i also replaced the injectors with a spare set i had and it is still the same. Am still thinking it might need bigger injecters! Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 it shouldn't run lean under fuel cut as the standard ecu should fuel that just dandy, your injectors might be a bit grubby perhaps a good flush might stop the bogging down? if you replaced the dizzy etc is the timing on the dizzy spot on? Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 I had the problem before i replaced everything. It doesn't misfire at all, i dont know how to explain it, it just doesn't accelerate properly! Its like its struggling. I put some redex in today so will see if that helps but it must be running lean for the plugs to be white yeah? This is really bugging me now, should i get it put on an AFR or something to find out what its doing? Help someone!!!!!! Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 if the plugs are white yeah it would indicate it's running maybe slightly lean, but i wouldn't have though that would cause a lack of accelerationmaybe plug up a wide band and see what the fueling is like all the way round to red line, that will be the only way really to see if you are running lean...other than obviously going on a RR aswell.check all joins for leaks as that will effect top end power. Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 Another thing i was thinking was maybe i have an air leak, say inlet mani gasket or on the throttle body, do you think that could cause it? Cheers dude Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 if there is a leak it will cause a noticable difference, i don't know how much loss in power has accrued but it could be down to a leak somewhere...you'll be surprised how such as small leak in the engine can cause such a noticeable difference, i have a leak between my mani and head and it drives like crap lol.i would just double, double check every vac and pressure line, jubilee, t piece you have.maybe right a list of all the potential causes and do an elimination thing one by one till you find what is causing it. Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 Thanks for the advice mate. Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 no probs ;) hope you find the problem, if you cant someone else might be able to shed more light on the situation.i hate it when things go wrong and you just dont no why lol Quote Link to post Share on other sites
Toby@ToyTuning.com Posted March 17, 2009 Share Posted March 17, 2009 Could be throttle position sensor, could be a lot of things unfortunately. What is the full spec of the car? With a major vac leak you would get erratic idle, with exhaust leaks you should be able to distinguish the sound. Does it feel like she is actually hesitating, any misfire? Are you running stock ECU?T Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 GT spec Hybrid, HKS Actuator, HDI intercooler, SPSmanifold, decat, stainless exhaust system with midbox, Blitz DSBC, running 0.8 bar. Cant think of anything else. Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 Could be throttle position sensor, could be a lot of things unfortunately. What is the full spec of the car? With a major vac leak you would get erratic idle, with exhaust leaks you should be able to distinguish the sound. Does it feel like she is actually hesitating, any misfire? Are you running stock ECU?TThe idle is fine and its not blowing apart from a hole in the decat but i have covered it up with a jubilee clip and you cant hear it. It doesn't misfire, the turbo boosts straight up to 0.8 bar, it makes alot of noise but doesn't pull properly. Sometimes it pulls hard and sometimes it really struggles! I'm so confused! How much would i be looking at to get it on a rr for someone to look at the fueling. Oh and yeah standard ecu. Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 Could be throttle position sensor, could be a lot of things unfortunately. What is the full spec of the car? With a major vac leak you would get erratic idle, with exhaust leaks you should be able to distinguish the sound. Does it feel like she is actually hesitating, any misfire? Are you running stock ECU?Tif you get a hesitating feeling from the car is that to do with a exhaust leak?i get a hesitating from the car before it comes onto boost then picks up, i have a small leak in the mani- that's what causing the hesitating?sorry to jack the thread from you Alex lol Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 No worry's ;) Ithink thats just lag isn't it Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 How much would i be looking at to get it on a rr for someone to look at the fueling.crazyhorses racing by me charge £45 for an hour session to check fueling and a power run Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 cheers, think its gonna be the best option. Was thinking maybe could put it on a computer and it might come up with a fault on diagnostics!? Quote Link to post Share on other sites
Glanza_cl Posted March 17, 2009 Share Posted March 17, 2009 come down this way get it RR'd for an hour's sesh check the fueling, do some fault finding and then we can change arm rests while your this way ;) have you tried doing a diagnostic check? Quote Link to post Share on other sites
AlexGTAdv Posted March 17, 2009 Author Share Posted March 17, 2009 I may do that! No i haven't done one yet. i might take it down to my local garage tomorrow. Quote Link to post Share on other sites
AlexGTAdv Posted March 18, 2009 Author Share Posted March 18, 2009 didn't get a chance to take it to the garage but i have bought a new set of plugs to see if that makes any difference as i have done quite a few miles since i changed them! Quote Link to post Share on other sites
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