ok. i have done an acumulitive of over 30ish hours of searching/testing trying to find out what the problem is. Here is what is going on.

The car (91 crx with a b18a1) runs in limp mode just fine, it throws code 1, 4 and 6. o2, Crank Angle and Coolant sensors. the coolant sensor is not hooked up, and niether is the o2 sensor, but to the best of my understanding, those will not put the car in limp. i checked the wiring 6 or 7 times to the dizzy and all wiring was good except for the Crank angle wires. So to make sure there were no loose conections i ran a pair of wires right through the window and into B10 & B12. I put the key in run position after reseting the ecu (pulling the fuse) and it flashed 1 and 6. The car will not start with the Crank angle sensor hooked up.

I checked the Crank Angle sensor and got 396 ohms of resistance in it.
(350-750 is what i heard i wanted) Im at the end of my rope here, i just dont get it. the ecu is a PR4 OBDO.

I know the injectors work, and the dizzy is from the same year integra (i think).
Any ideas would be helpfull. Thanks for any insight on this puzzle of mine.

 

Also the ecu just today started flashing code 17 (vss {vehicle speed sensor}) I think this will put it in limp mode, but im not sure. I have been poking around at this for a week or two now and the vss is just now going off. Dont know if that changes anything but i thought it might make a difference maybe?

 

Any help guys? im just poking at things at this point.

 

So the coolant sensor is hooked up and it doesnt work. (it worked randomly one day when it overheated) And a few days later the tach is jumping around. It only starts jumping around after 3000 rpms and still cuts out at 3200 rpms. (still in limp mode)
Any ideas? Im going to check some of the wiring tomorrow, but other than that i dont know what to do.
Any help would be appreciated.

 

check the wires @ pins c1 and c2 on ecu, also the 2 blue wires at the distributor. you most likely have a loose wire or bad connection on these two wires.

 

Isn't C1 and C2 the TDC sensor? And would this trip code 4?

I will check the wires tomorrow morning. The wires don't want to take solder for some reason, is there another way of ensuring connectivity in this situation?

 

i ran into this same issue and ended up buying a new harness. but in the processs i figured out that the issue with mine throwing 4,6,10 and 17 it was those share the same ground and in the stock engine harness the ground gets old and rots or breaks in two and you have no connection for the ground to work , delume the harnes and find that wire and repair it or do what i did and just buy a chase bays harness , problem fixed!

 

Ok. I will check on those grounds. Do you know where they all come from/go to? What i really want to know is: Can i just run new grounds from the ECU (to where?) and from the sensors to where they need to go?
Does anyone know where all the grounds come from/go to?

 

so buying a $700 harness fixed it ? damn.

just check grounds like stated and try to fix it.if not buy another harness (not $700)

 

I checked the grounds and they seem to be fine. I ran a new pair of wires into the engine bay from from C1 and C2. I conected them to the B-g and B-y wires of the dizzy and then hooked up the CKS and it wouldn't start (would turn over and have spark). I disconnected the CKS and it started right up and is still in limp mode.

On other news i found a severely kinked hose in the coolant system and replaced the hose, it wasnt sucking any water into the engine so i put a hose up to the radiator, it got water all over, and now im throwing a code 9. {No. 1 Cylinder Position (CYP Sensor)}
I may have hooked some wires up wrong or something, so tomorrow i will re-check all the wires going to the dizzy.

Random Q....... If the CKP sensor, ( i believe strikes 4 times per rotation?) were hooked up to the TDC ( strikes once per rotation?) slots for the ecu, would it still run(in limp mode)? And if so, when i tried to hook up the Wires from the ECU for the CKP sensor, up to the TDC sensor make my car not run at all?

 

not 700 , the cm1 is 475 for a tucked harness and yes it fixed my issue , 4,6,10 share the same ground ( one wire) location unknown

 

Im pretty sure its not that ground wire, im not throwing code 10. I will un-loom it tomorrow or Tuesday after work and make sure about it tho. Does anyone know where this ground goes in/comes out of the harness?

P.S. thanks for all the help.

 

not positive but think it the one that bolts to the thermostat housing , gl

 

hey so check it out i had the same probem wit the car not startin with the wires in the correct spots i switched thm up an the only code i throw is 9 ill posthow i have themhooked up but i have tried every combo and still cant get rid of code 9

 

There are 4 at that spot. 3 of them run to the main plug on the harness running to the ECU, and the fourth one runs to a sensor on the back of the engine. (this is what they are on my harness, if someone knows thats where they arent suposed to be please tell me)
I replaced all of them with new wire....a larger guage wire (14), just in case.

Hatch kid, What car/engine? Do you know for sure that the sensors are good in it?

 

Also, i frogot to mention. Around the o2 sensor wire and also around four wires going to the dizzy is a ground wire (wrapping them) that goes to nothing.....? it has to be on there for a reason, and it runs to a ground wire on the engine, but it goes from the engine to... nothing. Does anyone know where they are supposed to go? if anywhere?

 

as you said it has to go to something , i agree , not sure what though. im 99% sure your issue it a ground as mine was. you could always remove the engine harness and delume and re wrap the whole thing and test each wire with a tester to check if its getting continituty and re wrap it when your done and try it again? alot of work i know but that seems to be the most thorrow route with out buying a new harness

 

I deloomed it about a week ago and replaced all the ground wires so i hope its not that. (i dont want to do it again lol) But! I took apart the ecu because it was only throwing 3 codes when i unpluged the B and C plugs. The ecu grounds to the chip board by the A B and C plugs by 4 screws that are soldered in, the solder had beed cracked around all the screws. I just resoldered them in and am going to test it now. What other dohc ecu's can i use? a pr4 is hard to find around here. Or can i use a sohc?

 

as far as testing to see if you throw codes tht should work i wouldnt reccomend driving it with the incorrect ecu, if you want to go to obd1 then i have a socketed one ill sell ya , but youll need to order a basemap to run it , pm me if you want it

 

I would like to keep it obdo (less work and less "money") unless it was cheep. I actually have an obd1 pr4, so all i would need is a obd0-obd1 conv. harness..... But that cost money. =( I don't really want to re-wire it all myself unless i had some female obd0 plugs to make a seperate conv. harness, i have done enough ghetto things on this swap! i don't know where i would get some female end plugs without buying the whole conv. harness?

 

Im pretty sure its the ecu. I found a pm6 and a pr4 here in town that i have to choose between. I am going to try the pm6. will keep you posted.

 

Ok i got the pm6 in and now its only throwing code 8 (TDC). So i checked the wiring and everything is good, but the wires on the dizzy are a bit...old. So i decided to replace the wires on the dizzy and wanted to make sure while im at it that all the sensors are hooked up right.

I want to make sure these are right. I think this is how these are wired up, but im not positive. Can anyone confirm these?\/ \/ \/ \/
TDC= 1 strike per rotation.
CYP= 4 strikes per rotation.
CKP= 24 strikes per rotation.

The worst comes to worse i will have to get a new dizzy. (is anyone has a pm6 or pr4 dizzy to sell for cheap pm me. Im currently using an obd1 dizzy.)

 

Ok, update time. The CKP and CYP wires were somehow backwards.....i think. I switched them around and it started right up and i was able to drive it home, but still throws code 4 (CKP). No longer throwing TDC. I know for a fact the Ho2 and thero. sensor is not hooked up but it is not throwing these codes. I Think im going to get a new/used dizzy and go from there.