I have this problem, now that I converted to OBD1.
Car runs strong and fine while idle and up to 60-70% throttle.

as soon as I hot WOT, car bucks and stalls. I have changed out the fuel filter, Main relay, dizzy, spark plugs and wires, and the ECU.

Can someone help?
Its a 91 hatch with a b16 converted over to a OBD1. In OBD0 mode it did not do this.

 

did you check and set your timing?

 

yes, timing is set.

 

that's weird. So can you identify if it's spark not getting to the cylinder thats causing the loss of power or fuel not getting to the cylinder or worse... compression loss.

Hows your fluids, no oil in coolant, excessive steam from exhaust?

 

no on all of the above. I am starting to think that it is fuel that is cutting off.
Or maybe I didnt connect the proper wire on the obd0-obd1 conversion harness.

All I can say is that as soon as I hit 100% full throttle. the car bucks like it wants to stop.

oil looks good, no oil in the coolant.I have a WB hooked up and I can see as soon as it happens it goes completly lean. So basically from 13.5 to 16. As soon as I lay off the gas a bit back to 13.5.

It only happens in WOT.

 

well, perhaps the ecu is being told the wrong information about the position of the throttle plate, check your throttle position sensor.

also, you didnt mention if you have any codes or not?

does the check engine light do its little 2 second POST when you first start the car, if not the light may not be hooked up so you dont THINK you have codes.

but i still say TPS

 

I dont have no codes.
I will try to change out the TB to see if that may be the problem.
maybe the fuel pump???

 

what ecu are you using ??
if you are obd1 and have a wideband then why not use uberdata and completely tune the car yourself ??

 

P28 (obd1-conversion), Chrome Pro.

I dont think the problem is the ECU or the bin. its gotta do something with fuel...

 

So you're going to check the fuel pressure and get back to us right ? =D

 

fuel pressure reads 40 at the filter.

I did notice that I forgot to change the TPS wires when I did my conversion to MPFI.

TPS Read 4.5 at idle and .4 at WOT.
I changed them and i am going to test the car at my break.

 

not sure how chrome works cuz im an uberdata guy
but what bin did you use for chrome ??

80% is where the ecu goes into open loop, so your bin might not have enough fueling in there

 

problem solved.

When I did my conversion to MPFI, I forgot to change over the TPS wires.
I put a multimeter on and at Idle(closed throttle) I was getting 4.5 and at WOT(I was getting .5v.

I changed the wires over and problem solved.

Thanks guys.