WOT brick wall and im stock??

[sacline]

hello fellow dsm'ers.. i have a 1990 talson tsi fwd.. its completly stock except a k&n filter and the "free mods" the boost gage says 13 psi max boost under full throttle.. my problem is at wot around 5k rpm i hit a brick wall. could i have fuel cut being stock? i replavced wires to accell 8mm, new plugs gapped at .28, this has me stumped as i have no major boost leakes.. the only one i have is comming from the turbo manifold. i also may have bad valve seals since running warm i sometimes burn oil at idle. the pcv valve will be replaced tommorow moring, i have read this may help that issue... any sugguestions or help would be greatly appreciated!

 

[Paul@RTM]

Sounds totally like fuel cut. You can absolutely get fuel cut on a totally stock car.

 

[MQTalon92]

You may want to check your fuel pressure at the fuel rail. Also check or change your fuel filter. I had a similar problem years ago with my 92 Laser and it was my fuel pump. There is also an issue that the stock wiring to the fuel pump is too smal to handle the voltage needed when you reach higher RPMs and the pump can't keep up. There are many good articles on Fuel Pump Rewire in the FAQ pages. I assume by the info you gave in your post that it is not misfiring as that could point to a ECU problem known to plague these cars. Hope this gives you a place to start looking. Good luck

 

[Mitsubishigst1999]

Also try replaceing your fuel pump to a Walboro 190 or 255, mabye yours is going bad.

 

[habitatguy187]

IC Pipe Tester

 

[chase4494]

everyone always says check your " and its always something to do with fuel... fuel cut has nothing to do with your fuel pump and your injectors ect ect... its because your maf is think that your motor is taking in to much air to handle so it shuts the injectors off and your spark at the same time... givving it that out of the blue complte deadness... same thing was happening to be.. go trew and make sure all your vacume lines are in good condition and or capped off... that seem'd to be what my prob was. and i am also bone stock fwd talon tsi...

 

[Paul@RTM]

fuel cut has nothing to do with your fuel pump and your injectors ect ect...

Didn't want to mention that being a newbie and all (I've been a DSMer since '95 so I'm not really a newbie) but this is one of the most commonly misunderstood concepts in the DSM world. It's the name I guess: FUEL cut. It must have something to do with fuel, right?

its because your maf is think that your motor is taking in to much air to handle so it shuts the injectors

This is why it's called fuel cut: the ECU CUTS FUEL to the injectors in response to what it interprets as too much airflow. It cuts fuel, thus fuel cut. Thus the name.

 

[keveka2]

your maf could be going bad as well

 

[hotrodssnova]

Regap your plugs to .23 . Then try again. It's free and takes half an hour. If it doesn't work, then try the $$ mods.
I'm thinking its colder up there, and your fuel mixture is getting richer., so regap the plugs and let us know.

 

[Bouche Dag]

Keep it simple! First do a BLT before you start throwing parts at it.

 

[sacline]

thanks guys. its very frustrating as it drives perfect except at wot.. i will gap my plugs smaller and put a new fuel filter on her and see if that works.... my main queston is to why i am getting fuel cut on stock motor....what is happening to get it or what is casuing it? can anyone give me a list of things i can do to narrow the options of whats causing this..? if my maf is goin bad should i get a 2g maf and 550 injectors? also at idle my oil gage drops real low....does this mean anything as to fuel cut?

 

[undefined0000]

thanks guys. its very frustrating as it drives perfect except at wot.. i will gap my plugs smaller and put a new fuel filter on her and see if that works.... my main queston is to why i am getting fuel cut on stock motor....what is happening to get it or what is casuing it? can anyone give me a list of things i can do to narrow the options of whats causing this..? if my maf is goin bad should i get a 2g maf and 550 injectors? also at idle my oil gage drops real low....does this mean anything as to fuel cut?

Low oil pressure at idle would be normal? How low? Mine gets maybe a centimeter and a half from the L at idle, when the oil gets warmer, it loses viscosity and causes lower pressure. I don't drive my car until the oil pressure drops to the first line on the gauge, the one in the middle.

 

[Paul@RTM]

also at idle my oil gage drops real low....does this mean anything as to fuel cut?

No, unrelated.

my main queston is to why i am getting fuel cut on stock motor....what is happening to get it or what is casuing it?

99% of the time on a vehicle running stock (or near stock) boost levels fuel cut is caused by a boost leak. On a DSM, the MAF is at the start of the intake system (before the turbo) and reads the air flow at that point. The ECU decides how much fuel to add to this air based on that reading. Any air that is lost after the turbo is unknown to the ECU (since it assumes whatever amount of air it initially saw at the MAF is present when it enters the engine). Any air that escapes from your intake stream after the MAF is going to throw off your A/F values (whether you hit fuel cut or not). Boost leaks are a pain in the butt to fix, but they absolutely must be fixed before your car will run correctly. You can have a couple of teeny tiny ones, but no significant leaks. This is why everyone will tell you the same thing: do a boost leak test (or BLT)! There's absolutely no shortcut or different strategy. You must first eliminate all significant leaks after the MAF. Will fixing any and all boost leaks solve every problem your car has or ever will have? Of course not. It can't cause a flat tire to become unflat, it can't unbreak a broken timing belt, it can't do alot of things. But a DSM that has a measureable boost leak will never run properly.

 

[habitatguy187]

my main queston is to why i am getting fuel cut on stock motor....what is happening to get it or what is casuing it?

This should be mandatory newb reading

The Essential Primer on the Diamond-Star Engine Control Units - Chapter 7

 

[GSTurbo1]

AFPR and wally 255 and turn it up to about 55 psi

 

[Cdc1221]

AFPR and wally 255 and turn it up to about 55 psi

How is this supposed to help anything?? So it will wash the cylinders and ruin the engine before he fixes his problems? No no no no no

As to the op's question. You stated it has a leak in the 'turbo manifold'. Im assuming you mean the exhaust mani. I suggest fixing this as any preturbo exhaust leaks effect turbo spool AND can throw off o2 readings which will cause fueling issues, along with the blt stated above. Good luck

 

[keveka2]

good luck keep us posted