Honda CRX Forum banner
21 - 40 of 48 Posts

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #21 ·
Unfortunately, there is no specific relation between the compression pressure in PSI and the compression ratio. To know the ratio you basically have to measure the pertinent volumes, which means pulling the head off--something I do not recommend doing.

I suggest starting with about a quarter-tank of regular-grade fuel, and listening for extra noises from the engine. Generally preignition (detonation, pinging) will show up under medium load at low RPMs when the engine is fully warmed up. If you get any, put a quarter-tank of premium-grade in. This will basically give you a half-tank's worth of mid-grade. If you still get that extra rattling or pinging noise, fill to the top with premium. You'll have a tank full of almost-premium-grade fuel at that point.

I have no experience with the details of most swaps, so I can't help you on your specific questions.

--DD
Ok sounds good, I'll try that out. Right now it has 3/4 tank 87, I'll probably drain it soon anyways cause it's old gas. Thank you for helping!
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #22 · (Edited)
You wasted your time typing all of that as it is IRRELEVENT to what is going on with the car, I don't need a back story about how you got this pile of parts.

You have told us NOTHING about where in the process you actually are in the swap, what you have done or haven't done to the car, what you have tried, haven't tried, ect.



Whew, good.
Where I am at in the swap is the engine and trans are in, I've put in shifter linkage, shifter, new pedal box, clutch and throttle cables, intake and exhaust manifolds are on. Basically all that's left is the wiring harness, coolant hoses, vaccuum lines, and fuel lines. I also have some other little things like alternator and such but I know how to do those things. I came to ask if anyone had a diagram for the hoses and lines, google search images were not enough. I also don't have any electrical / owners / service manuals but I'll try to find one in the junkyard.
 

·
Registered
Joined
·
1,793 Posts
Search this thread
CRXHX - D16Y5 swap, full OBD2 conversion.
Sorry I don't know how to link it.
There is a lot of information there with several images about wiring schematics.

As far as wiring goes it's all about matching the correct sensor on the engine with the correct location on the ecu for that sensor. Pay attention to polarity. + and gnds.
There is a difference between power ground and signal gnds at least on the position on the ecu; don't mix them up.

Service manual is the one used by Honda technitians, you will not find it at junk yard it needs to be downloaded online or search the specs you needs online, by now there is everything needed online. There is a ton of info on the forum you need to use the search button or the stikies.

GL
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #24 ·
Search this thread
CRXHX - D16Y5 swap, full OBD2 conversion.
Sorry I don't know how to link it.
There is a lot of information there with several images about wiring schematics.

As far as wiring goes it's all about matching the correct sensor on the engine with the correct location on the ecu for that sensor. Pay attention to polarity. + and gnds.
There is a difference between power ground and signal gnds at least on the position on the ecu; don't mix them up.

Service manual is the one used by Honda technitians, you will not find it at junk yard it needs to be downloaded online or search the specs you needs online, by now there is everything needed online. There is a ton of info on the forum you need to use the search button or the stikies.

GL
Thank you for the great read! Definitely learned a lot from reading through that thread :D Still got a whole lot to learn though, at least I have motivation again though :p The new harness I got is complete and is such a lifesaver. Just got the old chopped up one out and am planning to put the new one in after I get coolant hoses and vacuum lines all sorted out. I don't think I'll have to worry about the connectors hooking up to the ecu, at least I hope. From what I assume, if the pinout on pm9 doesn't match the pm5 connectors from ecu to strut tower connectors I'll have to tear into the loom D: My bad on the manual mixups, I did find one online but only for the sedan lol I'll definitely take a look at all the stickies and also just look harder in general haha. Sorry for the late reply school got kinda busy but I really appreciate sending that thread, cannot relay how much it taught me lol
Might also send pics of my engine bay and parts I've mentioned
Thank you again!
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #26 ·
Ok so I did some more digging and found the technician service manual, a whole 1000 + pages of info! I found radiator hose routing for mpfi which should be good enough for me. Will also look through wiring sections later if I need to. Just thought I'd post for anyone else who might need it later. Radiator section on page 100 link here
Organism Rectangle Font Parallel Urban design

Also realized vacuum line diagram / routing was on my hood so here's a picture of that too:
World Font Map Parallel Rectangle

and from the manual
Gesture Font Auto part Parallel Motor vehicle
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #28 ·
If you can, find a hard copy of the factory service manual, and pick that up, it is much easier to thumb through a physical copy when actually working on the car than fumbling with a device.
Those are GOLD and definitely where you should have started.
Oh ok I'll look into that, was also thinking of printing it all out at my dads work haha
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #30 ·
update:
I just realized that neither of diagrams for vacuum lines align with the ones in my car, maybe because whoever pulled the engine cut them all off and threw them away, but that's besides the point. Im going to be going to the junkyard to hopefully get some pictures and also some vacuum lines and t pieces if I need to. I'll try to see if my friend who knows efs really well isn't busy sometime soon, I know I don't have the experience or knowhow on how vacuum connections should be, he would know where they should go. Also did a lot of reading so I'll post some resources here so I can find them later. If anyone wants to help with the whole vacuum lines situation just lemme know and I'll post some pics. Thank You!

pgmfi.org library:

ef auto - manual:

basics on efi and ignition timing:
 

·
Registered
Joined
·
1,793 Posts
Post a pic of the engine from the top..

If you are using the D15B2 intake.
manifold with its TB and all sensors , it should be an easy task. Assuming you still have the map sensor and evap solenoid on the firewall location.
And its oem throttle cable, that one is lonnnng.
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #32 ·
Post a pic of the engine from the top..

If you are using the D15B2 intake.
manifold with its TB and all sensors , it should be an easy task. Assuming you still have the map sensor and evap solenoid on the firewall location.
And its oem throttle cable, that one is lonnnng.
Yeah I’m using all the dpfi parts, think I’m missing map though. I have charcoal canister but not sure about evap solenoid, I’ll look it up. Going to the junkyard tomorrow to get all the vac lines I’m missing and will pick up anything that I’m missing. Im also swapping to manual so I’m changing engine wiring harness and ecu. My original wiring harness “disappeared” so I got these two together. pm5 to pm9 ecu, putting harness and ecu in is all that’s left for manual swap. here are some pictures.
Car Vehicle Hood Automotive lighting Motor vehicle
Car Vehicle Wheel Motor vehicle Hood
 

Attachments

·
Registered
Joined
·
1,793 Posts
Your map sensor is inside that black box next to wiper motor iirc. same for the evap solenoid.
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #34 ·
Your map sensor is inside that black box next to wiper motor iirc. same for the evap solenoid.
oh, I just bought a map sensor from the junkyard yesterday, it wasn't covered so I thought it was different. I guess I need to pay more attention. It's always good to have a spare, also learned a lot about the locations of all the lines and hoses, I got almost every single one from the car there. Explains why all the diagrams were different, I'll figure something out with that. Oh yeah one more thing has been bothering me. I got some prelude seats from an ef si at the junkyard, for some reason the rails don't bold in. Maybe they made brackets or something, the carpet was in the way. I was thinking I would just drill holes and use nuts and bolts to secure them. Only 2/4 mounting points don't line up. Would that be fine for safety? Thanks in advance!
 

·
Registered
Joined
·
1,793 Posts
Try the bolts by themselves to make sure threads are good.
Prelude seat may be slightly different than the crx.
I swaped mines with integra seats, I got them for free.

I used the crx seat pans and rails but used the Teggys foam and fabric to ensure perfect fitment, again IDK if that can be achieved with the prelude seats, you will have to try it out. I did had to add a piece of foam to the seat pan because the integras did not had that extra foam on them.
I used the Teggys back support but had to drill 1 hole to the bottom bracket( the one that bolts to the back support) to make seat set just as the crx. Nothing hard, just a hole and bolt and a nut. If the bolt is not done the seat will be tilted back beyond safe driving, 60+ degrees tilted to the back; not good.

Once the car gets running the seats will be replaced with something nicer and sportier.
Dont forget to install the center piece where the emergency brake is, then try fitting the seats.
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #36 ·
Try the bolts by themselves to make sure threads are good.
Prelude seat may be slightly different than the crx.
I swaped mines with integra seats, I got them for free.

I used the crx seat pans and rails but used the Teggys foam and fabric to ensure perfect fitment, again IDK if that can be achieved with the prelude seats, you will have to try it out. I did had to add a piece of foam to the seat pan because the integras did not had that extra foam on them.
I used the Teggys back support but had to drill 1 hole to the bottom bracket( the one that bolts to the back support) to make seat set just as the crx. Nothing hard, just a hole and bolt and a nut. If the bolt is not done the seat will be tilted back beyond safe driving, 60+ degrees tilted to the back; not good.

Once the car gets running the seats will be replaced with something nicer and sportier.
Dont forget to install the center piece where the emergency brake is, then try fitting the seats.
My seatpans and upper seat got thrown away. I still have the rails but they don't match to the prelude seat pans. I also found the seats in a hatch si, not a crx, don't know if that changes anything. They sat well in the si hatch with the manual center console. Im reusing both the bolts that helf the original seats in as well as the prelude bolts. These seats are straight buckets and they're comfy, I plan on keeping them, just wanna keep it as safe as I can. Would thread tapping through the chassis work? Might send pics of the way it lines up. Thank you for all the help!
 

·
Registered
‘90 Civic DX Hatchback
Joined
·
24 Posts
Discussion Starter · #38 ·
What? If the seat mounts with 4 bolts, why would you think 2 would be safe?
What year Prelude seats are they from?
I meant I would create the other two mounting points. I just wanted to ask if drilling holes into the chassis and using a bolt and a nut to secure it was safe. Im not sure what year the seats are from. I'll send pictures of them and what I mean with the rails tonight when I get home.
 

·
Registered
Joined
·
1,793 Posts
Post a pic of the rails on the chassis, where they dont line up.
Given that you dont have the original seats rails chances are you will have to drill and bolt them up where thay stand.
 
21 - 40 of 48 Posts
Top