JUN1OR

Been troubleshooting this problem for a week. I rarely ask for help, but I'm stumped here.

91 CRX, 94 USDM b18c1, P06 ECU w/ Hondata s300 (now P72 ECU w/ s300).

I was driving the other day and car suddenly died on 3/4 load at about 4000 rpm, cold engine. No spark, no fuel, check engine light wouldn't even turn off when I turn the ignition to II. No fuel pump priming, nothing. I couldn't even connect to the ecu via Smanager anymore. OK dead ECU is most likely the problem. (previous guy installed the ECU replacement power supply capacitor terribly - too much heat, melted traces. I suspect it finally went)

I had a spare P72 GSR ECU around so I soldered in the pins, transistors, jumpers, etc, put the ECU in the car and voila, no check engine light and I can finally hear the fuel pump prime (didn't before). Upload my .cal, datalog record, try to start and no spark.

Pulled a plug out and checked spark, fail

Per factory manual and/or helmes, I tested and/or replaced:

- Tested coil, ok
- Tried replacement coil, no change
- Tested ignitor, ok
- Tried replacement ignitor, no change
- Tested main relay, ok
- Inspected and tested critical fuses underhood and dash, ok
- Pulled an injector harness off and hooked it up to a spare injector, clicked in my hand on startup, ok
- Bought and installed junkyard distributor, ok
- Cleaned ground on thermostat, ok
- Placed jumper wire from negative battery to a distributor leg, no change
- Tested ignition switch, ok
- The disti is spinning while cranking, no I don't have a broken timing belt.

What's weird is that now the check engine light doesn't come on at all, not even when I turn the ignition on! I did assign an aux input on the S300 to SCS, service connector switch, but I don't think it is related, as this was done years ago.

What am I missing? Bad install of S300 done by me? I'm decent at soldering, but who knows. I welcome all thoughts. Hondata sManager datalog (of engine cranking) and calabration attached.

Thanks in advance,

Mike

xxjimmyboixx

i thought u cant tune with a p72 ecu? im not sure though. my 2 cents

JUN1OR

Nope OBD1 p72 is great for tuning. Even better w/ Hondata than P28 since it has knock sensor board, if that floats your boat.

Anyway...

Perhaps I need a new ECU. I just don't have any other reason for no spark - and no check engine light with ignition. It normally turns on with ignition and shuts off 2 seconds later.

I even took the P72 out and re-touched up the solder points needed for s300 install.

Mike

RTUNED BUILT

it seems youre in the right track, my suggestion for u is to get a stock ecu and try it without installing the s300.

JUN1OR

I wish I could. I have 440 injectors, so it wouldn't run on a stock ecu.

At least I could test spark during cranking I guess.

Mike

JUN1OR

Turns out it was a bad ecu! All is well after replacing it.

manuel_gixxer

Hi I think got the same issue my car was in idle and out the no where just die it just crank but no fuel pump working I check everything the only thing I think it's the ecu is a hondata s300 v3 did you replace the whole ecu or find a virgin ecu and install the s300 on the new ecu?

JUN1OR

Wow this was years and years ago, but yes, the root cause was a terrible solder job on the original s300 install. I removed the s300 and reinstalled it into a virgin p72 (best ECU IMO), as it has every feature like knock control, butterfly control (GSR intake), etc.

Take the ECU cover off and take a look for leaky or blown capacitors. Send a picture here in this thread or PM.

jun1or