Eazy-EK902

Hello Everyone, and thanks for taking time out of your day to give me a hand but I have been at this issue now for 3 weeks and counting and after endless thread and forum searching through multiple sources I feel I have tried everything and this is my daily so life without it is dreadful. The car in question is my 97 EK hatchback originally was B18B1 swapped when I bought it ran great no CEL or issues, then I swapped it for a B18C1 GSR and modified the stock harness for vtec and ran it on a stock P72 OBD2A ecu with no issues or CEL (check engine light) until I spun a rod bearing at about 50 km/h and had the car towed home and later stripped the motor down to find no cylinder or head damage motor still ran after it spun.

So I deemed the head to be good had it resurfaced and purchased a b20b4 bottom end known good and running with low kms, the grey area and the only other thing I can think of is the headgasket I used, it was a B18C1 headgasket because I had a brand new one here in front of me when I installed it with the blox ls vtec kit. So the issue is I can start the car just fine with ALL sensors plugged in but after about 3-10 seconds the idle will drop, rpms will become shaky and stall completely start it up again and try to rev it and unless I am fluttering the gas pedal the car will die, if I stab the gas pedal its like it hits launch control and just breaks up and pops and then dies out, much like "existanzcivicb20" thread on his b20 issues and he has videos of the exact same issues as my b20 but the forum is dead and was not resolved. I bumped the TPS and IACV putting the engine in the car but have tried different known good units, I have also tried :

Multiple throttle bodies (for tps and map)
Entire fuel system
Timing( both mechanical and ignition )
Intake
Alternator ( because my BATT light came on )
Double checked wiring
Only CEL that pops up from time to time is P0141 (o2 heater circuit)

When pulling spark plug wires cylinder #3 does not affect the engine no rpm drop it I can hear the dizzy firing the plug wire so it seems to be good but the spark plugs are brand new only had 170 km put on them in my B18C1 and they are iridium. Only things I haven`t done was test connections with a multimeter, compression test, leakdown test. If you jump over to "existanzcivicb20" post labelled "B20B swap starts then dies" his attached videos are 100% identical to the symptoms I am experiencing I have done some searching but nobodies solutions have helped me same end result everytime. Please someone help me because Ive waited so long to get a b20v ek and I havent even gotten to take it out of my driveway and its been together for near a month now idles but wont move under load.

metalgear

I hate to reply with nothing of much help but I want to raise a question about the head gasket. B18b has an 81mm bore compared to 84mm for the B20. The gasket cleared the bore fine? I'm assuming so or you bolted the head on, just curious.

Also I had basically the same exact running issue with my obd1 b16a3 swap. (different setup I know..). I just stupidly had the tps and map connectors hooked up backwards. I highly doubt you've done the same but that was my fix so, throwing it out there. Check for volts at the connectors

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tony_2018

what ecu?

mk378

Compression test is a must on any used engine, ideally before buying it.

You're going to more cc displacement without retuning the ECU. This is going to make it run leaner.

Eazy-EK902

Its running a stock OBD2A B18C1 ecu, after checking the spark plugs I noticed a bit of coolant in cylinder #3 so I am on the fence that it may be the headgasket that is my culprit, I mean I did use a OEM GSR headgasket and there is some cylinder overlap. I just wanted to venture every avenue before tearing the engine down to inspect the rotating assembly and headgasket. I just seen others with similar issues to mine and wanted some insight if anyone experienced anything like it maybe thinking I overlooked something this isnt my first rodeo with swaps and I thought ive ran into every problem but keep getting surprised

Eazy-EK902

Turns out it was the headgasket that failed on cylinder 3, I took the head off yesterday and found 1 spotless clean piston, replaced the headgasket and I got my throttle response back but from the amount of water that got through into the exhaust it has 100% fouled out my O2 sensor now im back to sluggish performance but the car is driveable. Hope this helps someone I wish I would have checked it sooner. Thanks everyone

Smoove910

Shouldn't you use a headgasket for B20? Since B20 has 84mm cylinder compared to GSR 81mm. I went with a Golden Eagle headgasket for my B20 with GSR head.