Lude Generation

Hello,

I have some strange problems with my bb2 Prelude which has been converted (not by myself) to a jdm H22A.
The car has not been moved for one year, but ran superb for years, last week I tried to move the car to a friend's garage and after ~15min., as the car was "fully heated", the engine went off.
The next day I started the engine and everything was as usual until the radiator went on, ~2min. after that the engine went off again.
I was looking for errors, and as I unplugged the TW sensors and measured the resistance, I found a infinite resistance at the TW-sensor (cooling temperature, the one located on the side in direction to the frontbumper).
The second TW-sensor (radiator switch, located into the thermostat building) had ~12V, the workshop manual says it has to be 5V.
So I was wondering that no diagnostic lamp came on, then I unplugged the EGR, "cold running controller" (EACV?) and the injector resistor and the engine check light does not come!
If I turn the ignition on the check light comes up for 2 seconds and vanishes as if everything would be fine.
As I put the jumper into the diagnostic cable, the check light is constantly on.

Another problem I had faced and not solved is that every time I turn on something that constantly drains power ( AC, headlights etc...) my engine looses rev's and levels off at a slightly lower level than before. But if I turn on the indicators every time the indicators blink the engine struggles to keep the rpm, it's like a curve.
I thought that the alternator was broken and replaced it with a stronger one, but it behaved as before.
The battery is also replaced (70A).
The PGMFI main "relais" is checked and ok.

I don't want to but think that the ECU (jdm P13) is the source of my problems.
Could there be any other thing that causes these problems?
And why does no engine check light come up, do I have more problems than I see?

For me that's a really difficult problem and I need every information that you guys can throw at me,
thank you and regards from Berlin!

Adam

Welcome.
Sorry to hear of your woes.

The engine dying or struggling when you have anything with high load on, sounds like an earth fault.
Check all the earths to the engine are there, tight, not frayed or broken internally and the mating faces of all the leads/bolt heads/block etc. are clean.
Also make sure the battery terminals are clean and tight.
After that, check all the ht equipment out (leads, distributor cap, plugs, rotor arm) to make sure none of them ARE leaking down to earth.

Have you had the engine running with the egr unplugged? If you only put the ignition on with it unplugged but didn't start the engine, I don't think the ecu would log a fault.

I was thinking of an earth fault too.I briefly checked the surroundings of my ECU and found a few connections that weren't clean at all, those which I found were cleaned but it didn't help. I will check every possible connection but not today
Battery terminals are clean tight.
What do you mean with ht equipment (Sorry for my poor English),the distribution and main housing is brand new, and the other parts you listed and the MSD are ~5.000km old and correctly connected to the grounding.

I had the engine spin but not start as I removed the EGR, TW-sensors, "cold running controller" and injector resistor, without check engine light, and after that I plugged in the injector resistor and EGR, started the engine (successfully), the engine check light didn't turn on.

Thank you for your help!

Hochspannung, the Zündkabel, kerzen etc.

@Sailor may be better able to help though. It does seem you and wurly are on the same page anyway.

As Donald says, everything to do with the Zündanlage.

It looks as if one of the things you've checked has fixed the problem, though, even if it's unclear which one.

I forgot to say... I'm in Berlin for the next couple of days with work.
I might be able to offer a hand?!

hey guys,

thanks for your replies, I managed to get a probably working ECU and a temperature coolant sensor.

I think I got a few things wrong, because there's one coolant sensor in the cylinder head for the ECU and two temperature switches and one temperature sensor for the dashboard.
Guess I measured the wrong ones measured switches not sensors

Tomorrow I'll change the ECU's and hope that no check light pops up.
(Cause I still think that the diagnostic function does not work, no matter which sensor/valve I unplug no check light comes up)

Where in Berlin are you? The car is north of Berlin, I'd like to pick you up if necessary but I'm not mobile at the time, the only Vtec I can use are my legs.
If the ECU change fixes my problems I wouldn't want to waste your time...

Does anybody know the difference of an jdm ECU in comparison to an edm ECU?

I will keep you posted!

the jdm one will flag an error straight away as you don't have a knock sensor

This^^^^^

And yes, there are various sensors and switches. The Honda Service manual explains all their locations and functions.

If the ecu coolant thermosensor is knackered, in my experience, it shows up because if you start the car and just let it idle, as it warms up the idle speed starts to race (to around 1.5k if I recall correctly) before it's warm enough for the lambda sensor to kick in and then if you blip the throttle, it brings the idle back under control again. But you can prove it by testing the resistance hot/cold anyway (as described in the manual).


My hotel is by Checkpoint Charlie, I'm at an exhibition at the City Cube ( I think that's what it's called?!)

Hello!

I changed the ECU, hot idle valve, temperature sensor and IACV.
But the problem still occurs...
I made two short videos.
http://www.vidup.de/v/wcqlI/

The engine was running 15-20min. and then it starts to behave like this.

http://www.vidup.de/v/twM4N/

And after it dies, it won't restart again...

It does seem like an ignition problem but the ignition itself isn't old nor faulty (MSD Ignition Coil, MSD cables, MSD Finger/Cap and oem distributor and new spark plugs).
I once changed all parts which are listed above to oem but it didn't matter (included the distributor).

The problem depends on the temperature in the engine compartment, if the bonnet stays open the problem occurs much later than if it is closed.
All cables that are linked with the ignition seem okay, but I will measure them soon.

Thanks!