Frizzy

I bought a 90 CRX HF shell that had a turbo B series in it previously (and has full Si interior along with the front spindles). I got the car home and started working on putting my newly acquired B16A2 from a 2000 Civic Si in and after getting everything bolted up, I started working on getting everything plugged in and noticed that a few connectors were not right and then found out that there was stuff missing. Instead of dealing with the headache of redoing the harness, I grabbed the engine harness out of my parts car 88 Si. I started working on getting all of the right connectors on it for temp and distributor (OBD2a) and replacing busted ones and everything was going well. I got to the point of plugging everything in and I got to the last connector at the driver's side strut tower and noticed that it wasn't the same. The engine harness has a 6-pin rectangle connector and the chassis has a 8-pin circle connector. I was rather baffled so I took to the internet and found some good info, some bad and was rather confused as to where to go with it. I eventually just gave up on the computer and started working on the car.

I eventually did figure out how to get everything wired properly. Turns out that not only are the two wires missing for the fast idle on that connector, but there are other wires that need to be flopped around. On the 88 harness, the ignitor wire is on the passenger side connector so I cut it and ran a new wire for the driver's side connector that I swapped over. Also on the passenger side connector, the Cyl Position Sensor (CPS) + & - are flipped with the ECT and IAT sensor wires so I just de-pinned them and matched the colors up with the chassis harness (Blu/Grn & Blu/Yel; Yel/Red & Yel/Wht). There was another wire on the passenger side that I had to cut as well because it went where the old ignitor wire did and somewhere else, but I don't recall what it was for or the color (TPS or MAP I think).

Now after all of that, I found that the car runs like crap. At first I had a code 6, 10, and 21 that progressed to a code 0 (solid CEL) on my chipped p28. The car runs SUPER rich and fouls the plugs if I can't get it started in about 3 seconds. When it did start, it was blowing black smoke out and smoking out my front yard. There was terrible hesitation and wouldn't rev pass 4k or so. I checked all of my wiring and that is when I noticed that the TDC wires were flipped with the ECT and IAT wires on the harness (explains code 6 and 10, but no code 9?). After that was fixed, it still did not make a difference. I checked my grounds and I only have one 4ga one from the transmission to the chassis and the ground on the thermostat which were both secure (do I need the valve cover one?). I then took the J1 jumper out on my ECU, started the car, and it did not change anything with how it ran or the CEL codes (still code 0) so I put J1 back in. I took my ECU and put it in my buddies 100% stock 93 Civic Si and it started the first time like it normally would, but was a little rich and wouldn't rev pass 4k (limp mode?) or flash codes (code 0). Mind you, his car runs flawlessly with no codes. When I took his stock p28 and put it in my car, it would not start. I started to check timing and it turns out that it was advanced one tooth so I fixed that. Now the car won't start with either ECU. With the stock p28, I get code 8 and 21 (not worried about vtec at the moment). Code 8 is for the TDC wires so I checked my wiring and there is continuity between the OBD2a distributor connector and the connector at the passenger side (Red to Wht/Blu and Grn to Orn/Blu). I don't know if the code is from the OBD2 vtec dizzy not having the same TDC signal as a Z6 dizzy, or the sensor being bad, but I don't know how to confirm it without another dizzy. I HAD TO CLEAN THE PLUGS 10+ TIMES THROUGHOUT THIS PROCESS BECAUSE THEY WOULD KEEP FOULING.

I have swapped parts to see if they would make any difference and none have.

• Three IAT sensors
• Two MAP sensors (one TB mounted one firewall mounted)
• Two ECT sensors

I have verified that I have continuity to the ECU from each of those sensors and they all checkout appropriately.

When the car ran, it did run differently with the MAP, TPS, and EACV unplugged (individually) and would not start with both the IAT and ECT unplugged. My chipped p28 has the O2 disabled and I don't have one to test with although I did add the harness for it.

I know that each of the injectors are firing (tested with NOID lights) along with having spark (screwdriver method, I need to get a tester to see if it is sufficient). I don't know where the ignition timing is, but the mechanical timing is dead on. I'm running out of things to test and running really thin on ideas. I plan on trying an O2 sensor from the junkyard and seeing if I can borrow a GSR/B16 distributor from someone, just a matter of finding someone willing. I might also talk my buddy into letting me borrow his Neptune so I can see everything in real-time.

Do any of you guys (or gals) have any idea what to check next!?

p.s. this is on CRX Community as well.

Ef4doorwagon

O2 sensors can cause a car to do some strange things.

ProjetEF

If i understand everything, you say you have a Obd1 ECU (P28) with a 0bd2a distributor ?

Frizzy

Correct, everything has been hardwired. OBD1 ECU, OBD0 car, OBD2a dizzy (B16A2 from 2000 Civic Si). The wiring has been checked for continuity to the correct pins on the ECU from the dizzy so no issues there. All points are soldered and have heatshrink over the joint.

Now, just as I said before, "I don't know if the code [8] is from the OBD2 vtec dizzy not having the same TDC signal as a Z6 dizzy, or the sensor being bad...", but I will be testing another dizzy this weekend if things go as planned.

4drEF

The distributor you are using should work fine.
It would either be bad wiring or a bad distributor at this point.

Frizzy

I agree, but what has me confused is that it ran before when it was advanced a tooth and now it wont with the correct timing. And even then, if a new distributor fixes the no start issue, there is no way a dizzy could cause the car to run that rich is there? If it was in limp mode it could, but is it possible that it could do that on it's own?

Although, it could be a combo of the dizzy and O2 sensor and i'm just getting ahead of myself. I'm testing both this weekend, but in the meantime, any more ideas?

Laserjock

I think the key to the solution is there. If you could get it to start with a stock ECU it will confirm your wiring is correct.

Regarding the starting issue if the engine is full of gasoline and the sparkplugs are gunked it would have a very hard chance at starting. Drain the oil and clean the plugs and try again only after youre sure the wiring is correct.

Laserjock

Additionally, the battery voltage may be insufficient after all that cranking to get a good spark. Get a jump start.

4drEF

There isn't anything else in the system that will cause your ECU to throw you a trouble code 8.
Yes, distributors can cause fuel consumption problems. The ECU uses several sensors, including the ones in the distributor, to figure out injector duration and spark timing.

I wouldn't even bother with the O2 until all other codes are cleared. Often the O2 will trigger simply because it is detecting too much or too little fuel.

Frizzy

This is a fresh swap so I am not draining synthetic oil that only has like 20 minutes of idling on it. I have cleaned the spark plugs numerous times as well (forgot to mention that) and am tempted to swap those out. The battery was starting to get low and I have jump started it twice and left it charging for a half hour or so both times. The battery is no longer low.

I know the wiring is correct as I have traced EVERY wire from the sensor pigtail to the ECU and they are all correct, perfect continuity with the right polarity.

I'll get one while I'm at the junkyard just to play with and see if that changes anything. I've seen a couple people have luck with even just plugging one in.

Frizzy

Alright so I got the car running right!

Turns out the ECU was bad like I thought, but I am not sure on the distributor. I got a new ECU and dizzy to try on the motor and it started with both, but still ran like ***. I checked wiring again and something somewhere along the line got mismatched because I had two wires flipped on the engine harness side of the dizzy wiring causing the TDC code. Once those wires were flipped and the ECU reset, the car ran smooth! I did not test the first distributor on the motor to see if it ran correctly with it, but I think there is a good chance that it was fine all along and it was just the wiring throwing the code.

The car runs like a champ now even though it burns oil!