highly modified 91ss, pinging at 10psi. help!

[92ss satinsvoice]

hi every one. ive got a good question for you guys.

my friend has a 91ss. with a ej22t engine and ej20g heads, with a vf30 turbo.

hes having pinging problems because he has higher flowing heads and a bigger turbo. his maf is almost maxed out at 10psi. he's getting 4.5volts already.

we thought about putting the maf senser in a bigger tube and or take the plates off the senser.

any idea to fix this problem?

[douglas vincent]

Install the plastic JECS one, and ground the blue wire. This will give you some more room...

I did this PLUS I filled in the area on the JECs maf that is restrictive (from the outside) with epoxy, and then bored it out to give me even more room. I am hitting about 4.5 at 13 psi now.

[Imprezive]

He should be running some kind of fuel control, or at least put in a bigger MAF and monitor the Air Fuel ratio.

[555BCTurbo]

hes having pinging problems because he has higher flowing heads and a bigger turbo.

No, he is having pinging problems from running to lean...having higher flow will not make your motor automatically ping, and nor will running a larger turbo...but lack of proper provisions for fuelling can cause detonation.

For a short term fix, I would say turn the boost down.

[Binford]

hes having pinging problems because he has higher flowing heads and a bigger turbo.

No, he is having pinging problems from running to lean...having higher flow will not make your motor automatically ping, and nor will running a larger turbo...but lack of proper provisions for fuelling can cause detonation.

For a short term fix, I would say turn the boost down.

+1

[92ss satinsvoice]

hmm. ya he wasn't having this problem back when he had the ej20g with the td04 turbo on. he was running 19psi before the motor gave out.


i beleave he said his AFR's where 10:1 but when we where driving around i forgot to turn on the wide band to see what was up. it was just a short trip.

yes i beleave you are correct, he's car has not been tuned yet.

but then again i think his still runing the same map he was using for the 2.0. i dunno i have to talk to him again.

[Imprezive]

so he's runnig a stand alone??? What kind of pistons??? If he's using stock ones his comp ratio should be lower than stock. what about ignition timing?

[92ss satinsvoice]

he's got the perfect power set up.

hes running Wiseco pistons 7.5:1 comp, with stock ignition timing.

[douglas vincent]

what size injectors?

[92ss satinsvoice]

i beleave he has 550cc's or 750cc's. im going to call him tonight and ge all the info.

say what size are STI injectors?

[92ss satinsvoice]

ok i talked to him last night. hes got STI 550cc injec. piggy back perfect power.

and his not running the map he was using for the ej20g. he turned the boost down for now till he can tune it.

[Bane]

I've heard someone say to unscrew the rear plate off the back of the sensor in the metal maf. Registered much more flow, or something like that... dunno if that helps.

[douglas vincent]

A - he needs a bigger MAF, or a modified JECS.

B- he needs to go to Global Settings and set the ANALOG setting for upper fuel to 4.9

The 550 Sti injectors are fine and dandy for up to at least 14-15 psi, probably more, its just that the MAF signal, once it goes over 4.9 freaks out the ECU and you end up leanish. Happend to me, happenend to another friend, and we are all running DOHC heads with STI injectors AND 12-18 psi.

But I don't get ping.....

[92ss satinsvoice]

heh, well he just got the perfect power stand alone from work so, besicly all the problems are gone now. now just needs a tune!