bigdongsr94

drove it sunday, jspec TII motor in s4 gxl. Complete emission and idle control removal. Basically I have nothing on my manifold. The car under light throttle little load will rev up and down. Trying to cruise across a parking lot is difficult. Can I fix this without all the manifold junk. I have a TPS of coarse but everything else has been plated. Also the secondarys dont seem to come on. As far as ive searched, the car cant be in neutral and the boost sensor has to see boost. What other things could cause this. I have not hooked up my neutral switch but i did jumper it to ground and it wasnt the fix? Clutch switch?

-efini-

^ im having similar problems with my 88jspec -> 1990 GXL. It bucks and hesitates under light throttle, idle surges from about 500-1k. Throttle response sucks. From about 6-7k it starts to back fire while WOT. Im preaty positive i dont have a vaccum leak. I have checked every single line. Maybe my Tps and Timming...

bigdongsr94

funny you mention TPS. I can view the output on my SAFC and without the car running it is veryy linear and seems correct. With the car running the output changes up and down as if it were getting noise from something.

DoriFCto

Seems like a faulty TPS. Have you checked it? My idle was steady but after applying light throttle it bounces.

bigdongsr94

"I can view the output on my SAFC and without the car running it is veryy linear and seems correct" thats what i sadi

jacobcartmill

iTrader: (6)

even though the SAFC is saying the TPS is reading correctly, you still have to set the TPS correctly so the ECU (THAT CONTROLS YOUR ENGINE) sees what it needs to see.

bigdongsr94

well I measured the TPS and it came out alright, swapped it anyway and it works great now. Main problem is no secondarys. I measured the boost sensor with pressure and at 0 it is low 2.xx V and at 8 PSI its about 3.4 V. It seems to function correctly. THe neutral switch is off. THe clutch switch is correct. What else could keep the secondarys from commin on. If i rev up with it in neutral (ecu doesnt see neutral) and apply pressure to boost sensor can i read the secondarys trying to come on?

My5ABaby

iTrader: (7)

If they have no power they wouldn't come on. Check to make sure they're getting voltage. I'd also look at the engine ground under your throttle body. If it was off they might not come on.

bigdongsr94

I measured 5v in. Im gonna change the safc to monitor the boost signal rather than TPS. I have the neutral switch not wired so it always thinks its in gear. If I trick the boost sensor to see some boost and rev to 4000 they should come on correct (while in neutral). I have each rotor housing grounded, do I need an additional ground for the injectors? Which injectors are actually the secondarys?

My5ABaby

iTrader: (7)

Secondary fuel rail (top).

No, you're good if those grounds are working properly.

RRTEC

iTrader: (13)

Are you sure the fuel hoses are hooked up correctly? The J-spec hoses are actually the opposite of the US MArket spec metal lines....

My5ABaby

iTrader: (7)

If the hoses are reversed, will it run at all?

RRTEC

iTrader: (13)

I got my brother in laws car to start like that..... It will defintetly start, but it will not run well.

bigdongsr94

mine wouldnt start at all, they were initially backwards. I have a fuel pressure gauge also so that helps. I will try to see if I can check in neutral, im weary of hitting 4k with no secondarys ive done it enough already. I also want to check the boost sensor sgnal all the way to the ecu/safc. Any more ideas? Swap injectors if I see they are trying to come on.

jacobcartmill

iTrader: (6)

you might want to check out the resistor box underneath the untake right behind the passenger headlight. i replaced this ages ago in my first TII and it fixed the exact same problem you're having. also add a couple nice engine grounds and add a quality ground at the ECU where all the grounds branch back to.

and no, if you start an FC with the fuel lines backwards it will run for about 1 second before it empties the fuel line.

bigdongsr94

Your talking about the resister pack for the injectors right, ya ill read throught that as well. I have all the grounds though. I have a lug on each rotor housing with 4 gauge and a lug at the ecu bolted to floor that has the ecu grounds tied too. Do the injectors work once they see voltage or is the voltage there then the ground comes in?

bigdongsr94

well i wanted to come back and finish this. I read resistance through the pack and one leg was open so i just went to radioshack and got some and soldered them in. Thanks alot