Engine Problems

[Supraluva]

I recently got my mkii 7mgte running again after redoing the engine bay. The engine has a new engine harness, To4Z turbo, FFIM, 720cc injectors, AFPR, Aeromotive A1000 fuel pump, and is running the MAPECU. Now the engine starts right up and idle solid. It will rev up fine and sounds very strong at idle. However, once you apply load and try to drive the car, the engine will rev to about 2-3k then just let off. If you hold the gas constant at say, 25% throttle, the engine will rev up then just let off like you hit fuel cut, then just rev up again and continue the cycle. There is also no check engine light on. Does anyone have any clue what could be causing this?

As far as the MAPECU, it seems to be working fine. All the readings, such as TPS percentages, RPMs, and A/F ratios seem to be working fine. If you make adjustments to the fuel the A/f ratios do change which leads me to believe that its working ok. Any ideas??

 

[Supraluva]

No guesses??

 

[black91turbo]

check your codes...the light doesn't have to be on. Other than that I have no idea where to start.....hopefully one of the old-school guys can chime in and tell you what you need to look for. Good Luck

 

[gofastgeorge]

Sometimes an overly rich condition will cause that surge.

When it's doing that, what A/F ratio are you reading ?

 

[suprahooked]

Check the tps

 

[Supraluva]

I checked for codes and its throwing out 32 which is for the afm. Is this normal for running the MAPECU since it gets rid of the afm or should this code not be thrown out? If not normal why would the ecu throw a code for the afm?

 

[a_sesshoumaru]

code 32 is not normal for the map ecu, i am using it in mine and has never thrown that code, you should check your map ecu wiring again, did you use this? is yours pre 89 ? that is the wiring for the pre 89, seems your stock ecu is not seing the map signal

 

[Supraluva]

I double checked and triple checked the wiring and its all good. I changed the tps and the car runs under load now. However, the 32 code is still being thrown. COuld it be that my mapecu unit is bad?

 

[jetjock]

32 is not an AFM code on the GTE...

 

[b00stin87t]

I had the same issue last year. I had to reset the ecu by pull out the EFI Fuse. I wrote this issue on the forums at...
http://www.performancemotorresearch.co.nz/forum/index.php

MAP-ECU Man gave me a copy of his wiring diagram. I was off by one wire made the huge difference.

By the way what do you have your TPS Enrichment set to?

 

[Supraluva]

Well, tomorrow I'm gunna have the car on the dyno. I've only messed with the idle and the car seems to be idling ok at around 14 a/f. I haven't touched the tps enrichment yet. Do I need to use tps enrichment or is that just to fine tune the idle and partial throttle? I guess I'll triple check the wiring tomorrow before I make any runs on the dyno. I'll update you on what happens tomorrow. Thanks for all your help.

 

[a_sesshoumaru]

hey man, jetjock is right, in the gte the code 32 is the high altitud compensation sensor

 

[Supraluva]

Hmmm... I've never had this in the car as it was never on the swap list when I did the swap years ago. Its it ok if I run without one? How much would it effect my tune?

Jason