I recently bought a 91 integra and I'm getting the code 43 fuel supply system issue. The car is a crate motor b20 in it upfraded from the b18. A mechanic friend has trouble shooted it and determined he thinks the ecu is causing the issue. The car will run great for about 5-10 mins then the check engine light will come on and it will run very lean and choppy..if I up the rpms it will steady out but them continue running like crap. My question is can I "band aid" this issue with an adjustable fuel pressure regulator and up the psi a little? Or am I stuck spending a lot of money on an ecu or is there other options?

If the regulator idea is feasible what should the psi be set to?

 

Ecu for a 91 shouldn't cost more than 50. Adlai make sure you get one that is the same year as yours. 90 integras has external barometric pressure sensors, 91's had internal (in the ecu).

My code 43 was due to a bad gas cap. Lots of people also claim to changing the o2 solved the issue.

 

I changed o2 but I'll most definitely try the gas cap before the ecu. Did your code 43 cause the same issue and effect the drivability?

 

Not that i recall

 

Sorry im not the most mechanically inclined but I know to get the same year ecu but I get the ecu for the b20 to match the engine right?

Friend of mine said I need to get a p28 and get my car tuned to the ecu but isn't it more of a plug and play type deal for the 91?

 

No, just get a pr4 from the same year as your car.

Youd have to change A LOT to get the p28 to work.

Jumper obd0 to obd1
4 wire 02
Distributor

 

Due to financial issues I've had to put this project on backburner..I contacted a tuner and he said same thing you said ..until I brought up its an automatic..he said he's.not sure it will work with an automatic of my year. Any input?

 

might need a diffrent fuel pump or b20 or b18 ecu or base map burned on a obd1 ecu using a conversion harness.

If your using the original ecu that was in the 91 integra thats your problem get a the correct ecu to run the B20 engine.

 

What injectors did you use?

 

I'd have to look when I get home I didn't install any..I bought it hopin for a commuter didn't expect this..I'm learbing tho lol. What should I be using?

 

it is the stock ecu..My only question before I spend the money is my car is an automatic I heard it is a little different to convert to obd1..that's just what I was told could be false info that's why I ask

 

i wouldnt bother converting it to OBD1. Thats not necessarily going to fix the issue.

Id just bite the bullet and take it to someone who can properly diagnose the issue.

 

Just wondering if you reused your old ones or used the ones the b20 came with?

 

 

An adjustable FPR likely won't do anything. I don't think they have a tendency to fail! Your coil however, when its failing, will cause problems when it gets hot. This would make sense if you're getting it to run better with some throttle, since the ignition timing has to advance.

Other than that, the obd 1 teg ran slightly higher fuel pressure than the obd0, only a couple pounds though. I have the oem FPR from my 92 bolted to my 91 engine so it matches the car/ecu. I also used the OEM injectors from the blown 92 engine and the entire distributor. I know nothing about the b20 however compared to the b18. If the fuel pump hasnt been replaced, and was run low frequently it could be failing, the oem pumps are pretty resilient though! AH, light bulb, this has happened to me twice now! There's a plastic cover on the rear driver side, under the car, between the wheel and the gas tank. I think its 4 10mm bolts. Take that off and see of you have a bunch of rocks and mud sitting on that plastic plate, if you do, I'm willing to bet you have a small hole or two in your OEM fuel lines. I replaced my bad areas with rubber hose and "fuel injector" clamps. They're smooth and wont tear the fuel line like band clamps. I think it was 1/4 and 5/16 inch hose but don't quote me on that.