Hey guys, looking for some help with my 1990 Honda CRX ED9 D16Z5.
Build specs:
• D16Z5 1.6L DOHC, engine rebuilt (rings, seals, head porting)
• Heinrich Tuning aggressive camshafts
• BLOX adjustable cam gears (set to non-factory timing for tune)
• OBD1 conversion
• EMG tune (dohcvtec.pl) with launch control (~4500-5000rpm) and shift light
• L3 gearbox short final drive FD 4.4
• Exedy clutch, lightweight flywheel

History of problems:
1. After first mechanic visit (clutch, wheel bearing, brake pads, fluids) - car started hitting a wall at 4500-5000rpm cannot go above those RpM’s, CEL comes on, loses power but then I can rev past it. After restart CEL clears and same thing happens again.
2. I replaced the distributor with a new one (turned out to be cheap quality) - car ran better, CEL gone, but RPM issue remained.
3. Second mechanic replaced timing belt, water pump, tensioner, seals, spark plugs, oil. Now car cranks but won’t start at all ( I went for a drive about 5-10 minutes my car stalled when I was reversing). No spark. Put old distributor back in - still no start.


Any help appreciated, this car means a lot to me and I want to get it sorted properly.
Thanks

 

It sounds like launch control limiter is being engaged all the time. What tuning solution is this? Neptune, Hondata, etc?

If you have access to the calibration, check out the launch control settings, or get in touch with your tuner.

 

thanks for your feedback on that issue, ECU is a chipped P06 OBD1.
We think the original 4500–5000 rpm limiter issue may have been related to launch control / missing VSS signal. We’ll check that.



But after timing belt work the engine died completely and now spark is extremely weak / almost nonexistent even with another distributor. Fuel pump primes and CEL acts normal.

 

Assuming you are using ODB1 distributor w/ the OBD1 ECU - are you using an adapter harness for that or did you rewire the original harness? Since the car ran, the harness is likely fine but still worth checking.

The distributor being aftermarket might be dodgy - any "new" distributor for our engines I've always understood to be of poor quality. Was it "new" or reman? Remanufactured will at least still have some OE parts that carry over.

My first guess is that your original distributor failed, and the "new" one crapped out too both due to quality and stress from other ignition components.

1. Check your spark plug wire resistance - if you have bad spark plug wires they can be stressing out the coil in the distributor. This will lead to the coil failing. Should be less than 10k ohm per foot of wire.
2. Ensure you are using the correct spark plugs - they should be resistor style plugs. (edit - also check that the gap is correct)
2. Look inside the cap and rotor on the distributor for any arcing or other damage.
3. Check the ICM and coil in your original distributor if it was OEM - there should be guides for this - you will want to search, but I pasted a few examples below

As noted above, if the dist is new, it may just be bad quality. If the original looks OEM, you could replace the ICM, coil, and the cap/rotor if those are old. I've have bad experiences myself with cheap ignition components for our cars, so if possible stick to OEM or OE quality brands - NGK, Bosch, Sumitomo

https://honda-tech.com/how-tos/a/hon...-module-374873
https://honda-tech.com/forums/tech-m...search-729637/

Best of luck

 

Thanks for your response, Small update:

The distributor has now been replaced with an OEM unit. The car starts and runs normally again, so the ignition issue seems to be resolved.

However, the original problem remains:

• the engine will rev past 4500 rpm in neutral
  
• on 1st gear it can sometimes rev higher as well
  
• on higher gears it hits a hard cut at around 4500 rpm
  
• the cut sounds very similar to launch control / rolling anti-lag
  
• the speedometer does not work at all
  
• sometimes after attempting to go past 4500 rpm the Check Engine light comes on and the car loses power
  
• when the Check Engine comes on, the engine enters a reduced power mode
  
• after cycling the ignition, the Check Engine disappears and normal power returns
  
• during a second test drive the hard cut was still present, but the Check Engine did not come on
  

The fact that the OEM distributor fixed the no-start issue but did not change the 4500 rpm limiter makes me think these may actually be two separate problems.

At this point I'm wondering if the hard cut could be related to missing VSS/speed signal, OBD0->OBD1 conversion wiring, or something configured in the chipped P06 ECU rather than the distributor itself.

 

any codes showing for the ecu?

did you remove or disconnect the cylinder sensor on the end of the exhaust camshaft? for OBD1 this sensor is built into the OBD1 distributor.

i might suspect camshaft timing is not correct, possibly due the adjustable cam gears, which I assume are B-series gears. the B-series have different alignment markings from the stock PM7 gears.

 

Yes, without the VSS signal the ECU (with launch control enabled) isn't going to know when to turn launch control off.

It sounds like your VSS signal is missing; In our cars, the VSS to the ECU comes from the speedometer (in the dash). The speedometer gets it's information from the the transmission, via cable.

In your original post, it sounds like a new trans was installed - If you aren't getting any reading on the speedometer, I would look there first. The cable is either missing, damaged, or the VSS gear in the transmission or on the diff itself is damaged (hopefully not the latter).

On the top rear of the trans, over the diff, should be a place for the speedo cable to go. It can be difficult to clip in, so maybe it just isn't seated.

 

Hi, thank you. I ve just checked the cable from the Speedo to trans. First of all when I moved a car on first gear, the inside itself wasn’t spinning. When I reached to trans I saw that the cable was really easy to remove. I tried to clip it in ideal position, but as I don’t have any way to lift the car into comfortable position it was hard, I’ve put it in but I don’t think that’s correct position. I will check it with the mechanic tomorrow, but now I know it’s definitely something related to cable
placement or the vss gear.

The car Once went for clutch replacement after that problems started, so maybe that will be it.

 

Hi, I’ve tried to read the codes, but unfortunately it’s modified in some way by the tuner, and I’m waiting for the answer how to do it.

However check engine light only comes when I try to surpass the 4500 rpm, but disappears after restarting the car.

thank you