I have a 1993 del sol with a b16a2 engine and a p28 ecu hooked up to vafc vtec controller.

That being said, when the engine was swapped (the old engine was a 1.5L) the fuel pump wasn't. When ever i turn on the car it runs fine no CEL no nothing, but when you step on the accelerator hard (WOT), the engine 100% looses power and bogs down to 200 rpm and misfires until you let go of the accelerator.

But when you hit the accelerator gently, it revs like a beast. Could this be because of my fuel pump (which i think is 1,5L)??

(does anyone know if a car should have 2 map sensors hooked up because mine does and its really confusing)

 

No it's not the fuel pump. The stock pump can move plenty of fuel for practically any engine. It pumps a considerable excess which simply returns to the tank through the fuel pressure regulator and return line.

There should only be one MAP sensor. Likely to be part of your problem.

Also it sounds like there could be a problem with the TPS sensor, that is what tells the ECU that the driver has opened the throttle suddenly and it needs to inject more fuel. Test it with a voltmeter. Some throttle body setups work the TPS backwards so you need to swap the end wires so you have the proper ~0.4V = closed and ~4.5V = wide open.

 

i got a new tps and it runs fine on the voltage... the vafc reads sensor voltage...

one big thing that i don't know about is that the pressure sensor (thats what vafc calls it) is always at (-350mmHg) when you hit the gas hard it goes up to (-300mmHg) but when you hit the gas gently it goes up to (-340mmHg)..

should that even be in the negatives? im gonna go search what the pressure is...

also, the 2 map sensors.. one of them is connected to the vacum??? if i unplug it nothing changes nothing happens.. but then that means something has to go on that plug.. ill post some pics when i get home

(its reading pressure from the intake)

 

MAP sensor reads the pressure just beyond the throttle plate, which is essentially manifold vacuum. Some throttle bodies have the sensor mounted directly on top and others have a port on the top of the throttle body which goes to a hose to the sensor on the firewall. Remove your extra sensor and cap off the port. The ECU only needs one. There should be a large change in sensor reading going from key on engine not running (sensor at atmospheric pressure), to running at idle (sensor at about 18 inches vacuum).

 

ok i have the one mounted just above the throttle body... the other one is right next to the fuel filter. what do i do with the hose that was connected to the extra map sensor when i remove it? and will the sensor reading be different under pressure or voltage?

 

Find out which sensor is actually wired to the ECU (the P28 would have only one MAP input). I think that ECU has an internal BARO sensor. There were OBD0's had two MAP sensors but only one was connected to the engine, the other measured barometric pressure (open to the atmosphere). Later models had that sensor built into the ECU.

The extra hose just block it so there's no vacuum leak. The small port on the back of a lot of EX manifolds is used for the cruise control actuator, which you may not have.

 

ok when i get to my car im gonna follow the wire from my ecu to the map sensor to identify whats what... and while im at it, im gonna follow the wire from the other sensor as well to see where that thing is going to.

Im also gonna take some pictures of the throttle body and my vacuum as well. Im also gonna play around with the vacuum hose to see if theres any change in pressure.

another thing i should mention is that the hose in front of the throttle body, the one that connects to the engine, if i unplug it and and close it out, the car accelerates like a beauty, but when i reconnect that hose, the issues appear once again

 

all fixed, i had one wire off on the ecu (the map wires were mixed), i fixed it up and now it runs like a beauty... one quick question, i bought a 10.2mm sparkplug wire off of ebay and the car lost some serious power... is it true that the thinner the cable the better?

 

It is true that many ebay parts are crap. I would not use any sort of aftermarket spark wires at all. The stock ones are fine and made much better than most aftermarket.