chriswboon

Vehicle: 1989 honda CRX, d16z6, OBD1 swap, P28 ecu

Issue:car starts, goes up to about a thousand rpms and imediately dies, but runs with the map sensor unplugged. will at times run for 2-4 seconds then die. i can rev the car up pushing the gas pedal in and out rapidly, it wil go out to about 4-5 thousand rpms and in about ten seconds it will just drop off like fuel has been cut completely. i can keep the car running by taking a spray bottle full of fuel and spraying into the throttle body.

Things ive tried:

replacing map,

replacing Tps,

replacing distributor,

checking distributor wiring,

replacing CTS,

replacing FIT valve,

running car with iac off and ports taped,

stripping harness and checking for broken wires.

checking to see if Vtec is engaged,



I had a b18 running in the car until i took it out and put this d16 in that also came out of a running car.

any ideas will help, thanks

zedron

iTrader: (1)

What engine harness are you using?

chriswboon

obd0 swapped to obd1

zedron

iTrader: (1)

I would put the IAC back on. Why do you have it off anyways?

delsolproblems

afaik he just took it off temporarily for diagnostic purposes and should have it back on now. He's also tried 2 different ECU's. MAP is reading .7v i believe (23HG) at idle. He says the TPS reads .5-4.5v and that the fuel pressure is 40+. For some reason his computer is supplying the wrong amount of fuel, even when the motor is cold.

delsolproblems

It's not something usually done at home but you could check the injector spray patterns- see for yourself how they are squirting. There are ways to do this using glass jars to catch the fuel while you watch the spray. It should come up if you google injector testing. You can also have them flow tested & cleaned professionally at places like Dr.Injector but testing them off the car won't show all fuel system problems.

fcm

As always, if there is a fuel problem, the first place to look is at the PGM-FI Main Relay, you did not mention the relay.

delsolproblems says you have 40+ PSI fuel pressure, is that constant, even when engine is stalling?

Have you checked voltage at the injectors, is it constant?
If the injector relay, [in PGM-FI Main Relay] has burnt contacts, enough current may pass to keep fuel pump relay on but not enough to power the injectors properly.

If you have not already, pull the PGM-FI Main Relay and inspect it, defective solder connections and burnt contacts are common on older main relays... http://techauto.awardspace.com/mainrelay.html

Unless you can test them, replace any fuse that has anything to do with the ign. system or fuel system, even if it looks good, the only way to know for sure if a fuse is good, is to test it under load, a brand new fuse is a distant second.
A proper fuse test is best done with a 12V test light.94

chriswboon

the main relay is good because the car will run good when the map sensor is disconnected, the car started and the map reconnected. because of this i am leaning towards more of a variable or something with changing values that would be effected by the map being unplugged. the fuel pressure does raise when the car is accelerated or being cranked to about 45-47. it will even hold fuel pressure over night. the voltage at the injectors holds a straight 12V( or battery volatage) and pulses ground when the car is running. at other times it seems they just stop at free will. if you need anymore info, pictures of the set up, anything that will help with the diagnosis please ask. also the IAC is reconnected lol

fcm

You said "at other times it seems they just stop at free will" do you mean the injectors?
If so, what do you not have, the 12V or the pulsed ground? 94

chriswboon

the ground will stop pulsing. now it seems to have a miss when you start it with the map unplugged lol. i love this car

fcm

So it is an ECU/ECM issue, sensors supplying info to the ECU/ECM or wiring between sensors and ECU/ECM.

Also remember the output of the injector relay in the PCM-FI Main Relay supplies power not only to the injectors, it also supplies power, [signal] to the ECU/ECM along with a few engine sensors/valves, [depending on MM&Y]. 94

chriswboon

hey i have a video of the injectors firing. sometimes they fire sometimes they dont but they always prime. it seems that when its upside down itll fire everytime lol. other times they will fire very faintly. and i know i have fuel in the tank. text me at 862 268 1869 ill send it.

schia89

have you checked the fuel pump n filter?

chriswboon

No I had planned on it tomorrow. My fuel pressure gauge is on the outlet of the filter tho so I doubt it's thE issue I'll let u know tomorrow.

teg91boy

i have a stock 91 integra gs with intake exhaust with a similar issue. im getting fuel all the way up towards the injector but not firing at all. the fuel pump is priming and i can hear it while trying to crank the car. the car will crank and crank but no start..??? i have an obd 2 dzzy rewired to obd 0 plugs. im getting spark, ive tried 2 different ecu's and resister boxes but still not starting???wtf

chriswboon

i still cant figure it out lol. i gave up for now and am buying a fit.

delsolproblems

When you get back to working on it, make sure the valve and ignition timing are on.

chriswboon

im converting a serial cable to read the values of the ECU ill let you know the results. buying a new car is a bitch move i refuse lol

chriswboon

valve ignition timing is on. remember that the car runs perfect when the map is disconnected.

delsolproblems

Changes to the air fuel ratio will change the ideal timing, but it seems that's not the case. Looking forward to the results.

TeamWeakLine

dang dude i had the same issue

chriswboon

im data logging it this weekend ill let u know