Need Major Help!

[TopStreet240]

okay guys, its time to pool your heads together. I have a ka24et amd ot os pm 12psi. I have a problem which can only be describes as a full cut of power at different times under boost. The magic number of mph seems to be about 80mph and it happens most when shifting from 3rd to 4th gear, but it sometimes happens in 3rd and also in 5th gear. I dont know what it is, but it seems like i lose all fuel or timing or something, it is as if im hitting a limiter??? I have the fuel for the car so i dont think that is the issue (550cc injectors and fuel pump) and i have a 3inch AFM. Im not sure what it could be, I dont even know where to start. the only thing i can say is that its not because the car is to rich... checked a volt meter and the tune is cherry. Could it be something with the ECU or does the 89 have some crazy limiter that i dont know about???? has anyone run across this problem or does anyone have any thoughts... im open to try anything, i cant race anyone till i get this fixed... i spin till about 80 and then just hit the limiter... damn 195's and open diff.Jake

[andrave]

what rpm's is this happening at?sounds like a problem with your mafs, how is it setup?

[TopStreet240]

it is a stock maf but expanded to 3 inch. The rpm is about 4000- 5000rpm... the only thing is, i just noticed this today, that when this happens at that rpm my SAFC reads 6600-6900 rpm. Im thinking that something is telling me im overreving????

[andrave]

stock tach can be inaccurate, but that inaccurate???thats almost 2000 rpm off. If that is the case you are just smacking it off the rev limiter.

btw, when mine felt like that it, it turned out to be my mafs adaptor plate was blocking the signal to the mafs..

[TopStreet240]

I dont think thats it either... i have a straight 3inch pipe with the MAFS in it... it is a custom 3inch mafs. I dont think the tach is that off either... so im totally confused? do you think it could be a bad ecu?

[andrave]

I don't know then... I think the disparity between your stock tach and your SAFC tach is defintely significant...

[zachosz]

My KA24E used to do the same thing from time to time, but it would happen around 3-4K. Mine was N/A, so your problem might be non-turbo related. I never solved the problem, but I think it's a good idea to check your AIV, make sure all your electrical connections are clean, no vacuum leaks, etc.

[TopStreet240]

well, Im going to try and vent my bov back into the intake and see if that helps.

[C-Kwik]

Check your spark plug gap. Particularly if you are running the stock ignition. With more air and more fuel in the combustion chamber, there is more resistance. If this is the problem, reducing the gap should solve the problem. But getting up towards 12 psi, I'd be thinking about upgrading the ingition. Too small a gap exposes less of the mixture to the spark.

[TopStreet240]

i will be changing plugs and wires very soon, but i dont think that was it...because i had the problem when i was non turbo

[andrave]

hindsight is always 20/20 but if you have a problem before you turbo, adding forced induction is usually just going to worsen it.

[TopStreet240]

well after taking my cat off and finding it totally clogged and find a huge 3inch cut in my intake, i figured that had something to do with the problem. Im working it out right now and will hopefully be running cherry tonight or tomorrow.....

[TopStreet240]

oh the cat and intake stuff was when my car was NA

[mys13240]

does your speedometer work fine? My car was doing the same type of thing. when i would hit around 4000 rpm it would cut out until i got back down to 3K. it turned out that the problem was my speed sensor. i guess since it was bad the ecu was getting the signal that i was hitting the speed limiter. anyways, i put another speed sensor in and i dont have the problem anymore.

[TopStreet240]

no my speedo doesnt work. I think i will try that. thanks

[mys13240]

yeap you should try it and tell me if that helps you or not.

[bigE]

Same thing happened here, our speedo sensor was crapping out, causing us to hit the governor in all gears, it was a pain in the *** driving in parking losts sometimes, it's cut off, then kick in leaving us burning tires. I'd say unplug the sensor plug and see what happens.

Eric

[3rD GeAr]

deffinately check the speedo and get it hooked up. i had the same problem and once i got it hooked up and working... it was fine.

[TopStreet240]

did you still have the limiter at like 112 or whatever?

[mys13240]

my rev limiter kicks in around 116. when my speed sensor was f***ed up it would kick in sooner.

[3rD GeAr]

yeah. i had to deal with the 115 speed limiter for a while til i got the jwt ecu. now. i dont know how fast i go because gauge only goes to 115.. good luck

[TopStreet240]

hahaha, yeah i dont think im going to get the ecu, im just going to snip the wire!

[WDRacing]

So is your car fixed??

[TopStreet240]

hahah, i wish, i dont think im going to fix it... cruised the local strip last night and didnt have a problem telling the ta's 5.0's and any other car that wanted some who was boss. I am going to order the part this week.