Decided to swap a 92 ka24de into my 71 510 and run into some issues.
little background: Car was originally a auto and the reason the guy told me he parted it out was because the torque converter went out. I bought a manual ecu and am using the can/am wiring set up. Using a Walbro 255 fuel pump. I removed the egr and the vacuum lines on back of the block. First ever swap and now stuck but I did try to research and can't get anywhere. Have exhaust manifold and down pipe on but have not finished running the exhaust.
SYMPTOMS: will not idle with maf plugged in but will idle all day unplugged. Took maf cleaner and still no go. Start up with maf unplugged> runs fine> plug maf in> idles high for second, hunts then stumbles and dies.
So first reaction is bad maf easy enough, bought a used one off eBay- same thing. like I should have done first time, I downloaded the fsm and did some test with the multimeter. I have continuity to ground and have proper voltage to maf. With maf plugged in and car off, the voltage test reads about .20v and when I blow into the maf it jumps past 1v so I think it's good.
REPLACED: so like I said I bought the new/used maf off eBay. Also replaced the cooling temp sensor, 02 sensor, cap, rotor, and spark plug. Took the idle air control valve off, cleaned and re-installed. Checked the injectors ohms and listened to them click holding a long screw driver on them... all ok
Also replaced the tps.
TPS-so the voltage checked out on the tps but the ohms were a little off so I replaced it and set the voltage to .50v
A interesting thing about the tps is it will not run with it unplugged but I read in order to set timing it must be disconnected. Maybe because the maf is also unplugged, but then the car should be in open loop anyways right?
Fuel pressure: hooked up a fuel pressure Guage and holds 40 psi all day.
Vacuum: don't believe I have any leaks. Checked my vacuum lines multiple times for cracks or open ports. I ran the engine and spayed carb cleaner around hoses and manifold and nothing. I put a hose on the brake booster, "capped" off the throttle body and blew cigar smoke into the intake (as seen on youtube Scott kilmer) and could find no smoke leaking out. Hooked up a vaccum gauge and when maf is unplugged it idles at 20hg on the gauge but with the maf plugged in fluctuates between like 10 and 15.
so I hope I proved I did my homework (read about every thread on Google about ka idle and dieing) and tried on my own before asking I'm just simply stuck. It's pouring outside so figured I might as well right this essay on help since I can't be working on my car.
1] maybe I bought two bad mafs?
2] maybe ecu is bad?(but it runs in open loop)
3] bad wiring? (Im a Rookie with electrical and using multimeter so my last resort is to break into the harness)
4] why does car die when I unplug tps?
5] grounds. Battery is in trunk so have battery grounded to trunk body then have another two gauge from engine block to frame. Can/am box is grounded to chassis. Do I need ground on the ecu?
I guess I'm not so good on figuring things on my own but I think I'm pretty good on following instructions and tutorials as that's how I got this far. Just don't understand why it runs in open loop but dies with what seems to be a good maf. I don't mind buying another one but at this point I'm kinda just throwing money at it and i would like opinions or maybe I'm missing something very simple. Thank you guys and I will try to find pictures, it's pouring down right now so can't take any new ones