Guest ON3GO Posted November 16, 2005 Share Posted November 16, 2005 Okay.. i cant figure this out. Its a N/A Mr2 that has a JDM Gen 3 i think turbo engine. came in for a bigger turbo and etc. did all the work and its running stock boost right now. it had this problem also before the turbo swap so its nothing i changed or did. okay.. so ur driving it.. if you dont get into boost or mash it it drives fine. if you ease into the gas and build boost slow and then give it almost or full throttle Sometimes it will be fine others no. if i just floor it most the time it messes up. what it feels like is a soft touch rev limiter but its not.. i thought it was maybe the fuel pump going bad but i dunno really. it sounds like its backfiring reallllly fast like boucing off a rev limiter but it isnt. its not pinging at all, not that i can hear anyways and the plugs look alittttle lean but look on the safe/good side. has new plugs, new wires. afm is fine as it did it with the other known good afm. it has a MSD Digital 6 ignition, brand new turbo, bov and etc. car pulls awesome when it doesnt sputter. werid part is when the weather was abit colder at night tonight i floored it and it was 100% fine.. then maybe it happened abit when i gassed it in 4th gear. so i think maybe its tempature related.. like a sensor getting hot but im not sure at all. any ideas?? mike Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted November 16, 2005 Share Posted November 16, 2005 I'd say running lean but since it was good in cold weather, I don't know, since the problem should be more pronounced. Does it have a TPS? I know some cars are real touchy with that, the 300zx comes into mind. Mario Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 16, 2005 Share Posted November 16, 2005 ya it has TPS and i thought it could be that.. ill check that tomorrow. i thought lean too but again im lost on this car. mike Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted November 16, 2005 Share Posted November 16, 2005 If you have access to an LM-1 (or similar), put the wideband on it and see what it is doing (lean, rich, etc). It is a good diagnosis tool as well as tuning tool... Quote Link to comment Share on other sites More sharing options...
Guest Aguyandaredhead Posted November 16, 2005 Share Posted November 16, 2005 Just a quick thought Mike, I know you said it was running stock boost but have you checked it with a real gauge. The factory one can be off by some and the car has a FCD (fuel Cut on over boost). It makes sense that in a low gear the car will not have time to build too much boost and has much less of a load compared to a 4th gear stomp. Which I am sure builds boost faster and to a higher level. I know HKS has a device to eliminate the fuel cut and there is also a quick fix out on the net for it as well. Does the car run like crap (like limp mode) untill you cycle the key on and off to reset the ECU? Jeff Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 16, 2005 Share Posted November 16, 2005 it has a fcd from HKS and its running a real good boost gauge. it doesnt like hit fuel cut, if it did i would have to turn the car off and then it would be fine.. but its not doing that at all. its just like hitting a rev limiter.... well its not but feels like it is. if i floor it and it does it, i can back off the gas and give it some throttle and build boost but not go WOT and its fine. so i dont have the cycle the ignition on and off. its deff not fuel cut as this car has it before and i know how it feels as ive delt with that problem before on toyotas and its nothing like this. Mike.. the LM-1 i have, but his exhaust/downpipe doesnt have the correct bung for the 02 sesnor. he doesnt want me to weld in a bung either so im sorta shat outta luck there. mike Quote Link to comment Share on other sites More sharing options...
Pyro Posted November 16, 2005 Share Posted November 16, 2005 A small head gasket leak during boost will do that. A little water injection into one cylinder will make it run like that. I have seen that happen on a friends car. Took a while to figure that one out. I'm not saying that is it, just something else to consider. good luck. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 16, 2005 Share Posted November 16, 2005 im thinking it has something to do with ignition.. i didnt go to work today, im sick as hell, hurts so much just to swallow. ill check the car out tomorrow. still open for ideas and thanks for the ideas also. mike Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 18, 2005 Share Posted November 18, 2005 wanted to follow up on this.. turns out it was the plugs.. wrong heat range. well atleast i think it is because we changed them and all went away. its still cold out so if it gets hot again ill see if the problem comes up again. on a side note i started and drove my 1st MR2 n/a to JDM Turbo swap today. runs awesome! tomorrow i hook up the gauges, make all the wiring look pretty, get a few things sorted out and then off to "awesome land" which is what i call the JDM engine importer shop i use. picking up a few engines and clips and coming back to finish the SR20DET head for the S12 200sx. mike Quote Link to comment Share on other sites More sharing options...
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