Boost Problem? Misfiring?

[TE27levin]

yes that a good point too.. not enough ground to the engine will cause false signal from the sensor. sensor will not work perfectly if the ground is too weak, and it might spoil your sensor,ecu, altanator... bla bla..

 

[SiGNAL]

acidburn,

Why u still go drag or street race with ur current engine problem??? Maybe u can use the AVCR and lower ur boost first until u find the problem if u wanna play drag or street race, if it continues like this, ur engine sure KO one. It's already getting worse and u still wanna push it..... at least solve the problem first man. Maybe u can try changing bigger cc injector and see if the problem still persist since u already upgrade everything else. Cheers

 

[GSR5559]

yeah.use AVCR to lower ur boost level first den solve the prob..by then, u can increase ur boost anytime u want..but becareful do not overboost cus ur internals might not upstand the high boost..unless u change ur gasket,pistons,piston rings,valves,valve seals and etc..to get a safer side of boosting high without damaging ur engine..
good luck

 

[acidburn1204]

Phat7,
My grounding cables r fine, thanx for the suggestion. I gotta feelin the problem might be with the ignition timing or somethin..

Dont get me wrong I'm not actually pushing it or performing at its current state. Would be abit DUH to do that :D .. haha. Its just that after sending it to the workshop to get it checked n repaired, I would have floor the accelerator to see if it still happens. Sometimes it happens sometimes it doesnt but gradually gets worse as it happens. I get it done for free but i dont think he(mechanic) has the right equipment to get it fixed once and for all + i'm a little low on cash if u know wat i mean. But overlooking all solutions, think im opting for dyno. Thats the best advice i got from other ppl and u fellaz. Thanx man.

Any idea how much the dyno + SAFC tuning might be? Heard N1's a good place to do it..

 

[acidburn1204]

Oh ya, engine tempreture somehow has a part to play in this problem. As the engine gets warmer, the problem gets more frequent. I have an oil tempreture gauge and it doesnt indicate anything abnormal. A friend of mine who owns an evo 6.5 said misfiring tends to be more consistant after the engine's warmed up..

 

[SPEEDSPiRiT]

DMT dyno is about 150++ i guess...
AFR tuning..

 

[kschu]

y dun get ur self a fuel regulator ?

 

[topui11]

bro acidburn

check your plug gaps and your ignition timing.

this also happens to me on my Rb20det. boosting around 0.6 bar.. all ok. then, try 0.7bar.. ok... but comes 0.8 and 0.9... poop! lower back to 0.7 bar.

after consulting a mechanic, i changed the plugs, regapped it, get new fuel filter, install GTR fuel pump and retard the initial timing. the timing part is a bit confusing and must do on-the-road test to get the right setting. now can boost 1 bar with no problem at all. i'd recommend dyno tuning if running above 1 bar.

BTW, this problem can be solve without going on to dyno la. i hate to see those guys when the revved the engine to limit.. not once or twice.... a lot oooo!!

phat7? hmm... adrian aaa? hehehe.. orange RX7. is it?

;)

 

[GSR5559]

this is wht happens to me ...
but my way of solving it is diff from topui11 ... (eeei still remember me wen the TT goin to Ulu Yam canceled due to heavy rain,ahha)

for 1.8T stock no mods :
boosting 0.6-0.8 bar no prob
boosting 0.9 - popopopo
den change higher cc injectors
boosting 1 bar no prob oredi..
no fuel regulators, no afc no nuthin at all to tune it but change injectors for my case...and i can reach 420 km for my 1.6 original full tank around RM 58-60 i think .. city and highway driving..

 

[topui11]

dude

it's easy for u to change injectors since u got only 4!! hahaha.. i need 6 maaa. but GTR fuel pump is enough for me. would benefit more with SAFC and FPR but that'll come later on la. so far, fuel consumption quite ok compared to other RB20det i've seen... full tank (around rm70) can go as much as 450km, average 420km. that's with a lot of tekan! hehe.. ;) better pray u didn't see me on the road la.. hahahaha

 

[GSR5559]

dude topui : how to check wht brand or from wht car the fuel pump is?
any performance increase if a bigger fuel pump installed ?
mebi the reaction of the car wont be laggy after putting in bigger fuel pump..ahah..jus my 2 cents though ..
and why u pray for who not to see u on the road ? later tekan tekan den mileage full tank oni 300km isit? ahhaha..

yeah and it is easy for me cus oni 4 injectors ... and almost evry car oso using 4 injectors..but 6 injectors more powerful mar..i always wanted to have those running on 6 injectors car..powerful and sound oso garang..like those RB's i jus luv the sound of the car wen it stalls..sigh..

 

[topui11]

dude

i osso dunno how to check but gtr fuel pump is a bit bigger than gtst pump. u want aa? hehe.. get from donut leh.

bigger fuel pump will ensure that your FPR won't be pressurizing too much for the injectors. better torque at low rpm and better response at high speed. laggy? that depends on your turbo setting la. hehe.. i don't think fuel pump will cause lag.

err... fuel consumption? dunno la... so far it's like my gtst pump also. today will take the gtr pump out to test another pump, hehehe... bosch 910.

haih... need to find FC series V injectors la like this.

 

[GSR5559]

oh yeah..donut the chop shop dude..
hei, ru dexster ? the one driving 180sx lastime?

 

[topui11]

dude

no la.. i'm not dexter la. but i wish i had his car. hehehe..

:lol:

 

[GSR5559]

oohh..u know him too isit? wher do u stay..heard dat he got 4 round lites behind sumtime ago..
ahahah

 

[gti[GSR]]

currently, i also facing pop...!!! like once or twice onli lar, if i drive at speeds of 140...!!! one day i was drivin den mah fwen tail gate me, from 2nd gear, i quickly upshit to 3rd gear, hehehe, suddenly can hear popopopopopo all da way...!!! but i tot it may coz of engine temperature... still cold, so not sure lar...

oh yea i read da previous posting, i also driving GSR, when i boost stock at 1 bar, ages ago, wif vr4 intercooler, back den, i had no problem or misfiring, wat so ever... fuellin was more den enuff as i used 7377 ECU, i heard its da auto ECU, me not very sure lar...

but yea... until now i still havent change da injectors...

 

[CarismaGT]

Originally posted by TE27levin@Sep 1 2004, 02:11 PM
miss fire? yes.. cos ur engine start to retart the ignition.
engine start knocking, knock sensor detact and retart your ignition to protect ur engine. it should be cause by running lean, weak fuel pump or bad fuel filter. it also can be cause by TDC ignition timing is too high. and one more maybe u using the wrong spark plug cos turbo need cold plug. hot plug will also cause detonation.
if u keep on holding the throttle.. u will see broken piston ring, broken con-rod or blew piston.

this is the best explaination regarding ur problem... anyway did u notice ur boost pressure when ur poping occurs? sometimes boost spike will be the cause and ur stock ECU will do the boost cut and this comes back to the same thing like what TE27 explain...

prolong usage of this problem will leads to faster engine wear and tear... suggest u send to a mechanic to rectify the problem...

dyno tune is one of the way u can fine tune ur SAFC... but i would suggest using Wideband O2 to tune ur SAFC... u can try GT Auto... they charge only RM350+- to tune ur SAFC + set ur AVCR instead... and with the wideband they can explain to u in detail wht is the max output u can draw from ur current Fueling...

 

[MRMIC2]

Hello acidburn,we meet again...
First check your ECU whether it is a stock ECU?For your engine should be red toyota label.It is located in your boot covered by carpet.
For the 1st/2nd Gen MR2 engine..The stock fuel pump,fuel regulator and injectors should easily take care of its fuelling below 1.1 bar boost.(430cc Sidefiring injectors)

Check your Blowoff valve spring tension...make sure it is tighten as too loose will cause boost loss.

As you have just installed the Supra fuel pump, installing a fuel pressure regulator gives you more control over the new fuel pressure.
What are your SAFC settings?pls elaborate...

The AVC-R shouldnt cause u any probs.

Check for loose/leaking vacuum hoses too.

Are your spark plugs the right heat range?
Check spark plug cables resistance if it snapped internally.


if all ok...then go for dyno to tune your afc.

Hope this helps

 

[phat7]

Topui11,

Me not adrian :o lah. My name is dave.