Bad spark plug wires? Or maybe power transistor?

[Kayo Stanciu]

Hey once again fellas

Probably bugging because last week I been asking a lot of questions . I apologize but I’m a nob and trying to learn the most I can and don’t really have an other place to turn but to experienced people in this and other groups.

I have a 1998 gst(manual) I recently just fixed my starter. I had this car I have now almost two years ago and times got hard so I sold it to a friend and two weeks ago I recently purchased it back from him. He drove it down to me an hour drive the starter was bad so I changed it had to replace it twice Autozone gave me a bad new starter so I had to return it. But anyways my valve cover was leaking so I replaced the gasket and as I do with any new cars I buy I changed the spark plugs and changed the oil and filter. So I get the car together, idles fine, and starts fine. I put the car in first and it has a power surge and wants to just get up and go even if it doesn’t do it right when I take off it does it when I let off the throttle in first only. I can’t go past 3500-4000rpm the car hogs down really bad and hesitates and I can’t get it to go past 30 mph. Idk what to do. I threw the old spark plugs in thinking maybe the car didn’t like the iridium plugs I put in. The new plugs with a dry black at the tips like bad. Idk what to do, I ordered new wires just in case because these ones look old anyways and figured it might be the plugs. But idk what else to do please some help and input would be great

 

[Kayo Stanciu]

If the tps is bad or out of adjustment that would definitely cause a problem. You press the gas pedal it opens the throttle body to let more air in the engine. If the tps doesn't know your letting air in it cant tell the ecu to put more fuel in and your car goes extremely lean and bogs down.

Nice, well I’m glad that I finally went and got a obd reader! Got a sensor today I’ll swoop out

 

[Kayo Stanciu]

Well changed out the tps, still nothing does the same thing and the cel is still there. I doubt clearing it will help anything. Should I maybe reset the ecu and see if that helps?

 

[Macgyver'sDSM]

Give it a shot probablycant hurt anything. But if your ecu is not seeing the tps that's definitely a problem. Sounds like you are going to have to start checking the wiring for continuity. And work your way back to the ecu from the tps. This is where ecmlink makes life a bit easier.

 

[Kayo Stanciu]

Give it a shot probablycant hurt anything. But if your ecu is not seeing the tps that's definitely a problem. Sounds like you are going to have to start checking the wiring for continuity. And work your way back to the ecu from the tps. This is where ecmlink makes life a bit easier.

I need to buy a ECMLink sometime soon .. driving me nuts! I just wanna drive my car but guess this is where the fun begins. I’ll try a reset and if not I’ll start tracing everything and see if I can find someone with a gst around me to borrow a ecu just in case

 

[Macgyver'sDSM]

Test all you can before throwing parts at it unless you just want new parts for piece of mind.

2G 4G63T TPS
1 - Green/Yellow (+5v Sensor Power)
2 - Brown/Red (TPS output voltage) should vary from .48 - .52 volts 0% throttle to 5 volts at 100% throttle
3 - Yellow/Red (IPS switch)
4 - Black (Ground)

 

[shinzon]

Something I haven't seen answered: have you done a boost leak test? Not being able to cross the boost threshold without the engine stumbling hard sounds like a classic bad boost leak.

Another question I didn't see answered: no CELs?

If you're not having a spark issue (ie plugs gaped right, strong spark from the coils, etc.), then the the next place I'd look is an air metering problem of some sort.

edit: BRP6EGP... those seem to be platinum plugs. 4G63 dislikes platinum plugs, often causing stumbling, hesitation, etc.; switch to a copper NGK. That could be your problem right there...

DSM spark plug FAQ: http://www.dsmtuners.com/threads/spark-plug-faq.233421/

 

[Macgyver'sDSM]

I would check the black ground for voltage as a few members have posted finding voltage there when their ecu's were having problems. Post #22 cel light tps

 

[Kayo Stanciu]

Test all you can before throwing parts at it unless you just want new parts for piece of mind.

2G 4G63T TPS
1 - Green/Yellow (+5v Sensor Power)
2 - Brown/Red (TPS output voltage) should vary from .48 - .52 volts 0% throttle to 5 volts at 100% throttle
3 - Yellow/Red (IPS switch)
4 - Black (Ground)

There’s certain parts I don’t ind changing to put new on specially ones that look original or old .. ecu I wanna try to avoid though so I’ll test everything before that. But if I do eventually have to replace an ecu or even use one to test will an automatic ecu work with manual car?

 

[Kayo Stanciu]

Something I haven't seen answered: have you done a boost leak test? Not being able to cross the boost threshold without the engine stumbling hard sounds like a classic bad boost leak.

Another question I didn't see answered: no CELs?

If you're not having a spark issue (ie plugs gaped right, strong spark from the coils, etc.), then the the next place I'd look is an air metering problem of some sort.

edit: BRP6EGP... those seem to be platinum plugs. 4G63 dislikes platinum plugs, often causing stumbling, hesitation, etc.; switch to a copper NGK. That could be your problem right there...

DSM spark plug FAQ: http://www.dsmtuners.com/threads/spark-plug-faq.233421/

I have only done a visual for boost leaks. I don’t have anything to blt it. And yea I mentioned the cel coming up as tps. I changed the tps and cel is still on there as tps.

I just put those because that was What originally was in there but I’ll order some cooper ones

 

[Kayo Stanciu]

I would check the black ground for voltage as a few members have posted finding voltage there when their ecu's were having problems. Post #22 cel light tps

Thank you I’ll check that out once the wind dies down here. I wish I had a garage to do everything

 

[jakk220]

I’m unsure to be honest but I can find out but I’ll try both firing orders and see what works. Best today when those plugs get here

Any luck with either order?

 

[Kayo Stanciu]

Any luck with either order?

The one that seems to work best was the 1g set up.

 

[Kayo Stanciu]

Well since I changed the tps and the cel for itnis still on any chances it could be the ecu?

 

[Turbo2g]

The engine light will stay on until you clear it with a scan tool. Thats how obd2 works.

 

[jakk220]

Well since I changed the tps and the cel for itnis still on any chances it could be the ecu?

Did you adjust the TPS properly when you put the new one in?

 

[Macgyver'sDSM]

As Shinzon mentioned a boost leak test is a good idea. If the mass air is seeing odd air flow from a leak that could cause a cel for the tps. Also is it a smooth loss of power or an abrupt jerking?

 

[chrysler kid]

Well since I changed the tps and the cel for itnis still on any chances it could be the ecu?

No the 98 black box ECU doesn't randomly fail on one sensor. There are no failure prone driver's like early ecu's in metal cases.

You cant just slap a new TPS on there it needs to be adjusted and calibrated

 

[Kayo Stanciu]

Ended up being a bad turbo. I finally got curious enough to pull it apart and the turbo has tons of shaft play and the blades were damaged a bit. When I first sold the car to my friend it had a 16g on it and for some reason he replaced it with a t25 and the t25 was pretty beat up looking. Replaced it back with a 16g and it works fine now. Thank you everyone

 

[Turbo2g]

Nice, and more power to boot

 

[Kayo Stanciu]

Nice, and more power to boot

Yes sir better than that stocked baby turbo