When i start it up it runs beautiful but after a little bit (warmed up) if i give it to much throttle it sounds like the engine shuts off (goes silent) let off the throttle it goes back to an idle. i was told a TPS would fix it so i spend $200 on one put it on and same F'n problem.

car details
89 GXL
91 JSPEC TII engine and tranny Also running on jap ECU
Latest AFC installed
has new alternator and PLENTY PLENTY of grounds.

 

any ideas?

 

Sounds like a lean mix - not enough fuel for the air you're letting in.

 

plugs and wires are new the car has a new alternator and plenty of grounds
the fuel pump is new the upgrade from summit racing and maintains around 50psi fuel pressure goes up when given throttle.

i have a aftermarket BOV but i removed that along time ago cause well stock seems better
im using an electric fan on a large aluminum 4 core radiator
boost sensor has been replaced, the clutch switch has been replaced and the ecu wiring has been gone through and inspected for proper readings iv changed through more than one ecu and iv even had the injectors all cleaned and checked.

Hopefully someone has some light for me at the end of this dark tunnel.

could it be as simple as i need to reset the ecu after installing the TPS ? i had the battery disconnected when i installed the TPs

 

50psi + on gauge increases with rpm

 

That's only one component of it, though - you may have plenty of fuel in the rail, but if the injectors aren't pulsing long enough or at the correct time, then it won't help you any. This would present as "When I step hard on the gas pedal, the car tries to die, but when I ease on the gas pedal slow, it gets past x rpm and then revs beautifully"

 

Fifty psi is about twelve too high.

 

i have the aftermarket fuel pump from summit and the fuel pressure reading is coming from the line b4 the rail.

and by easing on the throttle i'm talking about precision pressing not just driving easy or driving normally. im talking about coaxing the throttle as if your propositioning a girl into having sex easy. sometimes flooring it bypasses the dead zone. the mechanic that was working on the car before was a so called "EXPERT" Jr from Just racing fabrication and he specializes in rotary engines had my car for about 3 months and before I got frustrated with the wait he said he had changed the tps and it ran perfect, now after iv purchased a new one its doing the same damn thing. he's been through the entire wiring harness checked the injectors checked most all the sensors swapped ecus you name it I'm just pounding my head at a brick wall here. could the crank angle sensor be faulty or something ?

 

I've no idea what is wrong with your car. BUT, if the fuel pressure gauge is tee'd into the fuel pressure line prior to the fuel rails, the pressure your reading on that gauge IS the pressure in the fuel rails. I used the word TEE'D above.

Normal fuel rail pressure is written in the FSM in the FUEL AND EMISSIONS section of the FSM. Approx 28psi at idle and with zero vacuum on the FPR the pressure is something like 36-39 psi.

After the FPR starts seeing boost pressure, the fuel rail pressure will increase on the order of one psi fuel pressure for each psi seen at the FPR. Like at ten psi boost pressure the fuel pressure in the rail will be approx 49-50 psi.

If the gauge was deadheaded into the pressure line from the fuel pump, the pressue would be in the 80-90 psi range on a stock car. Real figures in the FSM.

 

im reading 50 psi on the lines at the firewall.i have a gauge permanatly tee'd on the pressure line. would the extra pressure cause the issue?i ask cause its not like the injectors are going to produce any more than they are sized too?

 

Update I replaced my battery, and it ran great for about 20 minutes strong no slack then it started up again i shut it off, cranked it back up ran fine the rest of the way home which was about 2 minutes from my house, when the problem occurs anything over 2000-3000 rpms the engine sounds like its shutting off if i hold the throttle it dies till around 2000 rpms then spits and sputters to stay running. if i let off the throttle it goes to a nice solid idle i can baby it to get where im going but you cant give it any throttle hardly.

 

Also i tried using the code tester but the plug that im suppose to use is missing a few wires so that idea is out of the question unless i tie directly into the ECU

 

NE1 have any other ideas?

 

i would check the fuel pressure as HAILERS told you it is way to high. set it arround 37psi. second Im surprised no one has sugested it. check your flowmeter. make sure the plug is connected well and that it is not loose or missing the clip. make sure its working properly. I had a similar problem and it ended up being that.

Good Luck

 

So it runs fine, as in you can drive it around, but then later on it acts up? For a second I thought maybe the lead and trailing plug wires were on wrong. But if it were that, you wouldn't be able to drive the car once the car over 2000 rpms give or take, much less drive down the street.

Tim

 

like iv said it almost acts like its going into limp mode after a very short time driving

 

Since it ran great with a new battery, then after a bit the battery ran down and it ran poorly again, maybe it's as simple as the alternator going bad. Easy enough to pull it and take to it Autozone for a free test.

 

he said it had a new alternator so he doesn't get upset again and have to repeat himself

Was it a brand new alternator or a rebuilt one from an auto parts store? The rebuilt ones are crap btw, or seem to be the case more often than people claiming they work great.

Tim

 

Do you have a CEL when this happens?

 

http://www.rotorwiki.com/index.php/89-91_Error_Codes

And yes, with fifty psi you'll inject more fuel than if the pressure was 37psi each time the injector opens.

Do the code thing: http://www.rotorwiki.com/index.php/89-91_Error_Codes

 

My fuel pump caused the same problem with my car.