[Mike Diaz]

I'm having a problem with my 91 CRX. My car ran fine up until 2 weeks ago. The car stalled on me while driving, and I had some clicking going on at the main relay. I cleaned all my ground and double checked all my wiring just to be sure, it straightened out the stalling.

Now when I start the car, the car runs smooth. I get a solid check engine light, my idle is about 1900-2000 RPM, and it feels like I have a rev limiter at about 3,400 RPM. The red LED on the ECU is not blinking, but it is on.

I need to know where to start. ECU? Distributor? I'm so lost without my car, please help.

Does anybody around Ohio have a PM5 computer? My buddy runs an import junkyard and we were trying to find out what other cars came with the PM5 ECU stock.

Any help is appreciated.

 

[cbp_crx]

usually when you have a solid light on the ecu, its time for a new one, when your rev. limter is that low, the car is in limp mode. Try a known good ecu, and that should solve your problems.

 

[jfrolang]

PM5 is completely the wrong ECU for a D16A6, you want a PM6. And a solid LED (aka code 0) = faulty ECU. It's running in limp mode, hence the low rev limit.

PM6 ECUs are available in 88-91 CRX Si, 89-91 Civic Si, and 90-91 Civic Ex.

 

[Mike Diaz]

I thought the PM6 was supposed to be there. I'm not a CRX expert. MY expertise is with the C32A and the C35A.

Thanks for the responses.'

If anybody wants a present for helping me out, here's my 3.5L RL powered Legend coupe:

 

[toxiclows]

when you say d16a6 swap do you mean the full si engine? Did you switch the car to mpfi? if so I cante see how it is even running on a pm5. . . . the pm5 is the dual point injection computer.. . Do you still have the stock dpfi?>?? if so then the computer is right. . . .. you must since you said that it was running fine. . . . the solid light is a bad ecu. . . .are you sure that it is a pm5? somethings fishy here. . .

if you did the mpfi swap you need the pm6

 

[toxiclows]

welll 3 ppl beat me to it . . . . .but hey look were all saying the same thing... WRONG COMPUTER are you sure it ran with this computer. . . i would not know how if you are mpfi. . . .the pm5 only knows how to fire 2 injectors. . and there are some other differences. . .

I am going to have to assume since you said that it ran that you have the stock dpfi on there. . . .. . and offer you a pm5 computer. . .. .i believe i still have one. . . . .let me know if you need it. . .

Chris

 

[jfrolang]

If it was an HF it would already be MPFI, and I don't know how a PM5 would have worked.

I thought the PM6 was supposed to be there.

Well you've got me confused now. What's actually in there?

 

[toxiclows]

maybe he ment pm6 or pm8 which would run the car. . .. . yeah i just caught the hf part at the top of the post. . . .. i just stupidly assumed dpfi car. . when he said swap and assumed dpfi was stock. . . not sure where he is coming up with this pm5 stuff. from. . . .

who knows maybe someone swapped the board and used the computers case. . . . >???? ?strange but possible. . .

 

[Mike Diaz]

It's definitely a PM5 ECU. I have the ECU cover off and I held the ECU in my hands.

I didn't do the 1.6 swap, I'll have to see if they left the DPFI system intact.

 

[toxiclows]

well if it is dpfi it will look like the top and mpfi looks like the bottom notice the manifold differences..

 

[toxiclows]

if ou have the bottome setup which you should if the car was an hf. . then you should NOThave the pm5 ecu it is WRONG>>>

The Si runs on the pm6 and the hf runs on the pm8 both of those ecu's will interchange... . just not optimally..... . as they are both mpfi ecu's the pm5 is for dual point only and i cant see how it ever worked with that. . .

Chris

 

[Mike Diaz]

My engine looks like the bottom one.

 

[jfrolang]

I don't know what else to say except find a PM6.

 

[toxiclows]

how well did this thing run. . . . As far as i know it would be physically impossible to run a mpfi setup on a pm5 dpfi ecu??? are you SURE that is what is in it. . . . you need to get a pm6 ideally but you can use a pr4 ( integra) or pm8 ( hf) to get it to run decently enough to get you around till you can find the right pm6

 

[toxiclows]

Theres a few on ebay right now. . . . There ya go . ..
http://motors.search.ebay.com/pm6_Parts-Accessories_W0QQcatrefZC6QQfromZR4QQsacatZ6028

 

[dohcrxl]

Not sure if anyone mentioned it but...

Just 'cause the ecu casing says pm5, it doesn't mean that the guts are pm5. At one time someone probably just switched out the casing for some reason. An actual pm5 will never run your mpfi engine.

 

[toxiclows]

yeah i had mentioned that .. . thats the only thing that makes sense. . . . .who knows what is going on with his poor car. . . .he just needs a good computer. . . . .and he should be set...[/quote]

 

[Mike Diaz]

It's possible, I got a PM5 computer from a friend and I'm going to compare the guts tonight.

 

[shorte]

If I remember right there's still a sticker on the inside of the ecu (on the guts) on top of the plastic where the plugs plug in, that has the same part #s as should be on the outside.