Hi Everyone,

Long time reader, never posted, but now I need some help.

I purchased a 91 CRX SI. Owner told me that the car runs, but turns off after 20 mins. Then you have to wait, 10 or 15, and its ready to go again for another 20 mins or so.

Took it to a mechanic and had some things changed.
-New fuel pump
-New battery

Done by previous owner 2 months ago by the same Mechanic.
-New thermostat
-New ignition lighter
-New coolant
-New main relay

When to pick it up today. Got 3 blocks away (not even 3 mins of driving) and the car died. Waited 10 mins, fired up again, and drove it for 15 mins, and then it died again.

It seems that the RPM is idling between 700 and 1200. That's when it dies pretty fast, when its idling around 1000, it seems to die much longer (aka 10 or 15 mins)

The check engine light is on, and the Mechanic said that some O2 sensors aren't connected and that the ECU is for an Auto rather then a 5 speed. So i've found a P28 ECU locally and will be switching that up, but could really use some advice so I don't just keep dumping money into it.

Thanks a lot everyone.

 

BUMP for help

 

even tho the previous owner said they replaced the main relay, you mite try getting your self another one...

 

Find out WHY the CEL is on, and what code(s) the ECU is showing. Look in the FAQs.

 

get rid of the CELs, first and foremost. match the ECU to the engine. (i don't think the P28 will run that D15b right, if it is in fact a three stage VTEC engine).

 

Can someone help me. What code do you get?

 

Im getting codes 21, 22, and 41?

 

Code 21 V-TEC control solenoid
Code 22 V-TEC pressure solenoid
Code 41 Heated oxygen sensor heater

your ECU and wiring are wrong.
take a photo of the engine, especially around the distributor, we need to see how many VTEC solenoids it has. take a photo of the ECU number.

 

If you reset the ECU, do all three codes return after driving the car?

 

K, i'll post a picture tomorrow. From memory, it does look like the vtec isn't connected.

The ECU is P28-C01 (aka i'm in canada), which is what i read needs to be run with the JDM D15B VTEC.

Not really sure what code 41 is, going to have to read up on it now. But could code 41 be causing the CRX to be turning off after 20 mins of driving?

From what i'm seeing, the car is turning off when it hits just below the half way mark in the temperature gauge. The longer I let it sit, the longer it runs when I turn it on.

Thanks for the help everyone. This is my first Honda, and my first project EVER. Definitely a learning curve.

 

How do i reset the ECU? I just plugged it in today. It had an ECU for an Automatic before.

 

Remove the Hazard fuse in the hood fuse box for about 5 minutes.

 

Unplug the O2 sensor to see if the "turning off" problem goes away.

 

Here is part 2. Please give your thoughts.

 

the oil pressure plug is destroyed, get a replacement. the SI doesn't have the provision for VTEC. i would REALLY consider getting a VTEC subharness from many of the guys here (hondapartsguy, rywire, etc.) to spare you from wiring it yourself. the O2 sensor is likely under the car in the J-pipe. check to see if it is connected. you will either need to get a heated 4-wire O2 sensor, or chip the ECU to disable the heater.

 

K, thanks.

Say, i wanted to build my own VTEC Subharness. Is there a parts list that I can use?

Same for the O2 sensor harness?

 

this should get you going. you will need OBD1 ECU pins, which could be obtained from various sources (do a google search, i won't favour one over the other by mentioning them here), a crimp tool and some connectors to do it right. i suggest against soldering, butt crimping wires and reusing old connectors.
what kind of OBD0-OBD1 harness are you using? it might have all the provisions for the VTEC conversion.

 

also, check what kind of O2 sensor you have installed. you will need a 4 wire one to do it right on a stock ECU.

 

Ya, i've seen the diagram. I know now that A4 and D6 need to be connected. I was more interested in the materials needed?

18 gauge wires? and any plastic connectors work?

Sorry, i didn't really make that clear.

 

no, you will need the proper connectors to the VTEC solenoid, VTEC oil pressure switch and the 4 wire O2 sensor, plus the ECU plug pins that will be crimped onto the wire.
to do the job right, the connectors will need to be virgin (not wired in already), or you will need replacement blade connectors that slide into the housing, plus the correct crimping tool the open barrel connectors.
there are suppliers out there that cater to DIY.

before you do that though, check your OBD0-OBD1 harness and see if it has provisions for VTEC wiring, it should look like a pigtail with loose wires on it.

 

Alright, taking your advice. I ordered a VTEC Subharness from Rywire. And just to save me some wiring time, i also bought a D16z6 VTEC Solenoid with the connecting plug and a Oil pressure switch. So when it all gets here, i'll install the new VTEC section and the new wires and then hopefully stuff will start to work.

Shitty part, is we just got a crap load of snow here. and the CRX is under a foot of snow for a week, until the cold snap ends. No big deal, sinces thats probably how long it will take parts to get here.

But now I can't jack the car up and see if the O2 sensors is down there.

 

Alright, all parts have arrived.

New OBD0 to OBD1 Jumper from Rywire with VTEC harness and new O2 sensor.

New (USED) Vtec Solenoid.

So I plan on installing everything on Friday. That should clear all the engine codes. Then we can go back at trying to find out why the car turns off at a certain temperature.

The Vtec Solenoid showed up in a zip lock bag, and it still had some oil in it. Whats the best way to clean it before installing it. Like the plugs are a bit dirty.

Also, on a positive note. I had an add posted here locally, about wanting to learn about engines if anyone had one to give away. Got a response from someone who said he had a blown D16Y8 that I could take for free if I wanted it. So I did.

Got home and cleaned it a bit. To my surprise its a D15B Vtec. WOO HOO. So this will be my learning engine. Something to take apart and spend weeks trying to put it back together.

 

OK. So new wire's are in. No more engine lights. But the car still turns off. What can I check now.

 

From what I know about the D15B, it uses the P08 ecu, and it uses a one wire o2 sensor. The p28 is used for the d16z6 which uses the four wire, heated o2 sensor. The rywire subharness you got will have the wiring in it for a 4 wire sensor (mine did). So if you plan to use the p28 then also get the 4 wire o2 sensor.

I advise you to take your time with the wiring. It is very important stuff, think of it as your cars nervous system.

When you replace the vtec solenoid make sure you get a new gasket for it. They are prone to leaking.

 

Got the 4 wire sensor. Everything is hooked up correctly. No Check Engine light anymore.

I'm going to check the spark plugs and distributor tomorrow. Anything specific I should be checking?

Also, I'm going to go read up on it, but what is a engine running rich or lean?