Hondata

Hi Built my self a Turbo EG and have been having issues...

Car is an EG civic with B18c4 engine, Holset turbo, 750cc grams injectors, Omni 4 bar map, S300v3, Walbro 255 pump, stock FPR, but pressure seems fine (mapper was happy with it). AEM wideband (IS it open loop i.e not wired into ECU). etc etc.
Car was mapped by a top UK tuner about 2 months ago. encountered a slight issue being that the injectors didn't seem to like idle, and fluctuate AFR.
Didn't cause a major issue though and car was mapped running 305bhp @10psi on the wastegate spring.

Mapper thought this was possibly a wiring issue, or injectors at fault, however couldn't pinpoint the issue, but managed to map the car and ran great.
while the car worked, AFR would fluctuate between 13-16.5 AFR, sometimes when getting hot go right down to 17AFR!
However under boost and driving the car had been fine.

One day the car just died... Pulled over checked everything seemed OK. Started car again worked fine.
Now the car seems to die constantly almost if the AFR drops off way too lean and the car dies. This has become un-driveable.

So looking to diagnose and fix the problem, have gone over most meachanicals at work (Tegiwa Imports) with the mechanic.
We replaced dissy cap which wasn't great, checked plugs BCR8ES (0.6mm). timing is good as was set with a timing light during mapping.
Checked for Vac leaks etc, checked wiring, cleaned and changed over the IACV - which made the car run sound, for 30 minutes or so.

Went for a good blast in her, car boosting well, driving great. Then car died again... this time the check light on dash displaying code 14 (IACV or ECM).
Now this code has gone but..

Now the car refuses to start at all, fired up and falls off. every time. I Have managed to get the car to start up once or twice but when blip the throttle the car dies. I have created a few datalogs, but wasn't 100% sure what graphs to display.

Could any one please shed some light please? what would be next things to check and test? MAP sensor faulty?

What is the serial number that is on the s300 board inside the ECU?

Do you have the wideband signal input into the ECU?

Hi. I can get the code off the ecu tomorrow.
The wideband is not wired into the ecu. This is something I plan to do soon but was a little unsure on how to proceed.
I'm guessing this Will this give better AFR reading stoich?

I really think this issue is related to maps sensor or its wiring. The car starts with the throttle applied which I tested today.

Checked the map sensor 5v which is correct.

Would it be a good idea to check the map signal wire voltages? Both at the ecu and the sensor end for a short? Is it d17?

Here is a datalog of the car starting with open throttle

Are you sure you don't have the MAP and TPS plugs swapped?

Yes. 100 correct car ran fine. For a few months.
Set the tps on a multi meter too.
Checked voltages on map sensor. Power wire 5v.signal wire 2.7v at the map sensor.
At ecu reads d19 reads 5v. and d17 reads 0v. Should d17 match the 2.7v?

I would recommend that you try this ECU on a known working vehicle first to determine if it is ECU related or something to do with your vehicle.

OK Yes I Will do, The ECU Code is S300 33100.

I have just tried a different ecu chipped and socketted with a basemap made up by a UK tuner. Still nothing.

I have just tried a different ecu chipped and socketted with a basemap made up by a UK tuner. Still nothing.

Have you tried your ECU on a known working vehicle?

Car cutting out when hot issue.

I have now replaced the plugs, and the car runs again now....

The other ECU (chipped and socketted p28 with basemap made by a tuner) runs the car also, however a little bit better idle, but the car still dies when it gets very hot.
Something is failing somewhere but I can't pinpoint it.

The issue is strange, the car gets up to temp and idles as it should however, when warm, the car will just cut out also under light load.
I have attached a datalog of this issue.

So far I have changed and tested:
- ECU's
- MAP sensor
- IAT sensor
- swapped engine loom
- HT leads
- swapped the Dizzy when hot straight after the issue. sill nothing.
- spark plugs
- main replay swapped and resoldered them
- compression tested (180 on all 4 cold)
- IACV swapped and cleaned them both.
- replaced the walbro 25 for a brand new unit fitted with new wiring straight to the battery with a relay.

Would someone please have a look at this datalog of the car idling at 2k rpm, then it just dies?
I think this might be quite obvious to someone who know what they are looking at with datalogs.

post the calibration that the datalog was made with.

Here is my calibration file.

Sounds like a similar issue to what I was having last year. Injector dead times were off. When the car was hot and cooling fans were on, my voltage would drop slightly and the injector offset was too low, causing it to lean out.

Correcting those and running in closed loop has resolved that problem.