2G hesitates

[1dohc6]

98 gst car sat for 2 years before I put the motor back in was previously running fine other than speedo not working. Car starts every time but only revs to 3 and super slow and hesitates and backfiring. Check engine lights on p1400 , p0120, p0105, p0300. Any thoughts on what could this? Thanks in advance Chris

 

[steve]

That's interesting with the +5v sensor power. If the MAF was bad I would expect it to pull the voltage down at both connectors not cut off the power to the TPS. Sounds more like a wire issue or measurement problems but can't rule out something I've never seen or understand.

Yes the power to the TPS needs to be solid before you can get a reliable TPS output voltage but the TPS adjustment on a 2G doesn't require it. The procedure sets the TPS location/rotation based on where the internal Idle Position Switch opens and closes and is based on continuity between pins 3 and 4.

 

[1dohc6]

Ok so I pulled out the engine wire harness and swapped it out with an extra I had laying around and still losing 5v at tps when maf is connected, and regain 5v at tps when maf is disconnected . What do you think could be going on?

I was also wondering how I could find out what transistor I blew In the old ecu. I’m gonna pull the new ecu when I get a chance to see if there is any damage. Thanks

 

[1dohc6]

Pictures of the replacement ecu let me know if you see something I don’t.

 

[steve]

Ok so I pulled out the engine wire harness and swapped it out with an extra I had laying around and still losing 5v at tps when maf is connected, and regain 5v at tps when maf is disconnected . What do you think could be going on?

Do you have another MAF?

 

[1dohc6]

I thought I did so I’ve been looking around and no luck. There’s a guy about an hour away that has a 2g maf for sale for $50 on Craigslist. Do the numbers on the maf have to be the same I have the 609 shown in picture... 609 and 055 are the same flow correct as long as it’s E5T06071 what if it’s E5T05071?

So the maf he has is md151055 and turbo side of the maf is round not oval, he said it came out of a 97 gsx

tk106 Has a maf for sale 055 E5T05071 turbo side is oval

 

[1dohc6]

Do you have another MAF?

Ordered the same maf i currently had just waiting for the seller to ship.
So since I was having issues before checking voltage on ecu pin 81, I checked it today with maf plugged in getting 0.07v and as soon as I unplug the maf plug I get 5.02 v on ecu pin 81. I guess was making contact every time I was checking voltage on pin 81 just couldn’t get 5v when maf was plugged in. Once I get the maf swapped....say the problem continues what could be causing me to lose 5v with maf plugged in I traced the green and yellow wire to check for damage before putting in the spare engine harness. thanks

 

[steve]

what could be causing me to lose 5v with maf plugged in

If the voltage is +5v without the MAF plugged in and next to 0v with it , it would seem that the MAF is shorted or that the ECU can't provide enough current.

I don't have any ECU's here with me in Colorado so I can't check the function of the transistor you burn't up in your old ECU but it wouldn't surprise me at this point is it was for the Sensor Power.

 

[1dohc6]

If the voltage is +5v without the MAF plugged in and next to 0v with it , it would seem that the MAF is shorted or that the ECU can't provide enough current.

I don't have any ECU's here with me in Colorado so I can't check the function of the transistor you burn't up in your old ECU but it wouldn't surprise me at this point is it was for the Sensor Power.

Been busy at work 104 hours last week so I’ve had no time to work on the car. Swapped out the maf today and now I get 5v at maf plug and tps plug car is running good other then the throttle sticking a little taking off from stopped position I might have messed up when replacing the shaft seals. I still have check engine code 0443 and now 0446 0403 1104 seems like there are all emission related. I want to purchase ecm link so I can clear those codes and pass emissions.
Does any one have a 95 eprom ecu for sale?

 

[1dohc6]

I hooked the egr back up and the egr solenoid,
No longer showing 0443 hooked up the hose from bov to Intake so it’s now recirculating no more 0403. I lost the boost control solenoid so 1104 is still on. I still have 0446 even after reinstalling evap purge solenoid I had to slice in the plug from my 98 harness to the 95 harness to be able to connect this solenoid. If the vacuum lines on the evap are not hooked up correctly (don’t have the charcoal canister anymore) will this throw a check engine light. If I cap everything off and just leave the solenoids plugged in will this throw a check engine light? Thanks

 

[1dohc6]

Can’t get ahold of any one from ecmlink been trying to email them since January. I’m sure they are busy but I would think i would get a response after two months I want to purchase v3 from them I do need a eprom ecu so if any one has one in working condition let me know thanks

 

[1dohc6]

So I have a boost control solenoid coming in tomorrow so that should fix one of the two cel. Im sure I narrowed down the 0446 cel when I removed the 98 wire harness I put in a 95 harness and it doesn't have the purge solenoid / differential switch plug (5 pin connector under driver seat) it connects to a body harness and is routed to the purge solenoid / differential switch on fuel tank. on the 95 harness. I can splice this plug onto the 95 harness?
wire colors:
Black (splice w black wire on rear o2 )
Red (splice w red wire on rear o2 )
Blue w white line (add to connector B-55 pin 61 which on 85 harness plug has no wire)
Blue w red line (add to connector B-55 pin 55 which on 85 harness plug has no wire)
Green w yellow line (splice 5 volt power source connector B56 pin 81 also green/yellow wire)

 

[1dohc6]

Connector 55 with both blue wires is from the 98 harness
Connector 55 with out blue wires is from the
95 harness

another thing should I remove pin 52 ( ignition timing adjustment connector 95-96)

 

[92AWDHX40]

With the 2g I'm not sure on wiring I used my ebc for my 1g from online diagram

 

[1dohc6]

Update: I rewired the evap purge/ differential switch plug to the 95 wire harness just like in post #36 and installed a stock bcs. No longer have a check engine light. Thanks everyone one that helped out. No more hesitation no more wire issues and no cel.