When my turbo starts to boost my car cuts out........any ideas???
- Thread starter edward_mccleary
- Start date
A big enough boost leak will cause you to hit fuel cut, check all your piping, also check to see if you have any diagnostic codes stored.
If you are stock, are you running over 10 psi of boost? I've experienced boost cut as low as 10.5-11 psi, although most experience it around 12-13 psi.
And as always, boost leaks are a big problem. Check the piping all the way from the turbo compressor to the throttle body. Some people have found very thin lateral splits in the rubber that leak under pressure.
And as always, boost leaks are a big problem. Check the piping all the way from the turbo compressor to the throttle body. Some people have found very thin lateral splits in the rubber that leak under pressure.
edward_mccleary;1075576 said:
im haveing the same problem right now,my car will idle great drive down the road but as soon as i hit the gas and the turbo pushes the motor dies, its like for some rreason it doesnt wanna go , i keep hearing its a boost leak , but my car is funny the stock boost gauge in the dash jumps to +8lbs as soon as i start my car and run it never dropping back down, ive checked all my elictrical, regaped plugs, checked wires,sprayed water on the intake to check for leaks, bov, intercooler, just about everything, i think it might have something to do with the ICS or the return line from the valve covers to the TBI , ya know those 2 lines that feed back into the stock turbo intake, wich i dont have on my car anymore, there are 3 codes i do get (12)-rpm signal, (42)-crank angle pulse, (51)-ac switch, pictures help im going to take a few more today and see if anyone can help me as well as you because i think we might have the same problem
it all started when i sprayed my afm with carb and choke cleaner it ruined it i couldnt find a stock afm so i bought one off a lexus i put the lexus sensor on the stock pipe and now it cuts out real bad at 4lbs of boost and it runs rich please help if any body has a stock 7mgte afm sensor i would like to buy or trade i have a 1 lexus afm sensor 2 lexus pipes and 1 stock pipe
i checked my codes and it said it was the trottle positioning sensor but would that make it cut out
87supraturbo19;1078145 said:
Any you? Lexus electronics in a stock Supra MAF???
I'm confused here. I thought you're supposed to use 7M electronics(so the ECU can cope) with the larger flowing MAF body from the Lexus???
If this is the case, I think I can see why you're both having problems.
Someone help me understand!!
hey i had the same problem and the retard i got the car from had the wastegate ''shimmed'' make sure theres no washers there! if u have an MBC it would help also make sure all your pipes are connected my intercooler pipe was half way off ...hopefuly ur boost gauge is connected right
I couldnt find a stock afm so i had to buy one off a lexus .I cant afford larger injecters so i am running the lexus sensor on the stock body .swd fredester 3 is sending me a stock afm set up and iam buying a trottle positioning sensor tomarrow the code said it was bad i will tell you all how it all works thanks swd fredester 3
good luck with that, another thing to check just in case, if your fuel pump is on the way out, you will hit what feels like boost cut.
it happened to me, sometimes 20 y/o pumps just get tired. as for shimming the wastegate, some people say its ok, some say its not. i would actually bet that just my saying that will cause an argument.
what that does is allow for "boost creep" which IMO is ok if kept in check, but if you have a shit load of washers back there will eventually do dammage, and cause boost cut, if you dont have correct supporting mods. i myself had a very small shim on my wastegate, and even at full throttle in 5th gear on the highway, the most i saw was 10 PSI, maybe 11 on a very cold day.
if your gauge is reading full boost at idle, there is something wrong, likely it is grounded out somewhere. but aftermarket gauges are quite cheap, easy to install, and much more accurate, so that may be your best bet.
as for the lexus AFM, an improperly tuned AFM without supporting mods can lead to trouble, so be careful and watch those A/F ratios.
it happened to me, sometimes 20 y/o pumps just get tired. as for shimming the wastegate, some people say its ok, some say its not. i would actually bet that just my saying that will cause an argument.
what that does is allow for "boost creep" which IMO is ok if kept in check, but if you have a shit load of washers back there will eventually do dammage, and cause boost cut, if you dont have correct supporting mods. i myself had a very small shim on my wastegate, and even at full throttle in 5th gear on the highway, the most i saw was 10 PSI, maybe 11 on a very cold day.
if your gauge is reading full boost at idle, there is something wrong, likely it is grounded out somewhere. but aftermarket gauges are quite cheap, easy to install, and much more accurate, so that may be your best bet.
as for the lexus AFM, an improperly tuned AFM without supporting mods can lead to trouble, so be careful and watch those A/F ratios.
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jetjock;1078171 said:
OK, I just woke up, and already I've learned something new!
That means I can be dumb for the rest of the day...:biglaugh:
I didn't know that the Lexus karman sensor was plug and play to the Supra harness, I guess because I always heard of people putting the Lexus MAF body in, but always using the stock electronics.
well i bought a throttle positioning sensor for 74.00 dallors and it is still cutting out so i am going to try a stock afm sensor ill tell you how that works
You said you checked the plug wires, but did you check the spark plugs themselves??
Maybe you've got them gapped really far out, making the spark blow out...
Maybe you've got them gapped really far out, making the spark blow out...
HAHAHA I have mine set at 10 sometimes hits 11, my car hits FC @ around 12 to 14psi depending on weather and stuff it seems like. When I first got my boost controller we hadn't tuned it yet and it being a Manual one it takes test runs to dial it in, well we had it set way too high and I hit FC @ 2400rpm's but man if the motor could do it thatd be badass because it was quick until FC, LOL.