ECU Question

[Beater88]

Ok Here goes:

I have a 88 REX that is giving me fits at the smog station here is my last thread that didnt get a decent conclusion:

http://www.automotiveforums.com/vbul...highlight=smog

Well I tried what was suggested and well...it got worse...

Soooooo anyway...

I was thinking that if I put in a PM8 HF ECU that would restrict the gas curve and lean the sucker out.

Anyone know for sure if the PM6 and PM8 are compatable. I looked at the ECU diagram and they look identical in connectors. I know that both are for MPFI, is there any issues that might arise?

I'm doing this because I know that it is running rich and that is what the smog guys tell me. Though my MPG is 30+ 38 on a recent trip.

Everything is basically new, cat, full tune, filter, oil, ect.

The smog tech also said that I might have a leaky injector or a bad coolant sensor? Anyone hear that one before?

Any other ideas would be great!

Thanks

[91civicDXdude]

if you run the pm8 ECU, you will have a check engine light for the EGR valve. I dont know if the tech people care about that stuff. I dont have smog in my state, so im not up on the smog info. It will run your car though.

Have you changed your o2 sensor?

also, i dont see how a "bad coolant sensor" would have anything to do with the car running rich.

[lilol89crx]

pm6 and pm8 are interchangable. like he said pm8 will set a cel for the egr lift valve. but running the pm8 would lean the fuel curve out and may possible cause your nox levels to climb and fail emissions anyways.

I just tried to pass my Beater88 Rex and it was a gross polluter!
Failed both HC and CO and 15mph and 25mph

HC@15 - 161 - Max - 121
HC@25 - 149 - Max - 96
CO@15 - 2.43 - Max - .76 (ouch!)
CO@25 - 2.56 - Max - .65 (That hurts!?!)

dayumn that thing is outta whack! hc even at 15mph is damn high. there is a possibility for leaky injectors, i would say the air filter may be too restrictive but it seems to clear out at 25 mph. no erradic idle? is the motor stock? the fuel man the pm6 is a little higher than the pm8 but not enough to smell fuel in the car. i would give the pm8 a try. the cel will come on though.

[ZCrazyman]

ok 2 things HC is a ignition problem and CO is a fuel problem

OK lets get this straight GET A "MF" STOCK CAT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! A high flow cat will kill you on emitions specailly on a older motor i know i've tried them b4

i'm a smog tech here in nor cal and i can tell you from personal experence that high HC will be your biggest problem your co will drop conciderebly when u fix the hc problem but most of that will clear up when u get rid of that freeking cat and get a real cat i know cuz i bought a new cat for my DOHC ZC and it passed like a new car

[Beater88]

Thanks guys!

Stock cat...why do they sell you hiflow cats if they dont work? I have heard this before and it is reasonable, but I wouldnt think that it would be legal to do so.

Where do you get a stock cat? It is not legal to purchase one from a salvage yard as there is some federal regulations and Honda wants something stupid like $500 for theirs, mine was clogged and the car ran like shit with it on...

Anyone have one for cheap?

I've used hiflows on several cars and never had an issue, of course those were v8 and 6 cylinder jeeps and mustangs. I had a 89 mustang with a 325hp motor and it passed just fine and I have a 92 YJ that has headers and hiflow and passed this year no issues at all.

Ignition problem...I had a issue when I put the intake on where I crossed the B12 and B10 wires and the timing was really retarded (no jokes please) and was unable to fix it until after a trip to LA, I did have the ECU toss a 9 code that trip which is TDC sensor (chiltons) or #1 cylinder sensor (for 1.6L as from this board), could that be blown buy the mistake, the wires were fixed and the car runs fine but every once in a while when I really wind the car out the thing codes 9. I just thought of this issue as I have not seen it in a while...That sensor is in the distributor, is it easy to replace? Could I have gotten the cylinder sensor wrong and not the TDC sensor? Would that give the same retarded timing? I would think that the car would not run at all or run like crap if I did that one...

Um...the air flow is good, I think, I have a K&N drop in filter and a less restrictive (modified) stock box. When I used the more restrictive setup like instructed the levels got worse.

Motor is a d15 with an Si manifold, dizzy, ecu.
Compression is perfect 175-180 across
Idle is perfect at 750, very smooth
o2 sensor is new, about 1000mi or so

It there anybody that can tell me if you can bypass the pm8 EGR sensor by putting the control pins to ground or 12v?

Thanks again!

[Beater88]

Anyone?

I know that I am a newbe to this board but I am no newbe to working on cars, just new to Hondas. As this is my first Honda this is not giving me the warm fuzzys to keep going with the brand. It has been easy enough to work in until now. I am sure that more people have heard of this issue, please help!

Thanks!

[Beater88]

Come on threre has to be some one that has run across and issue like this. I know that there are many CRX and civic here in NorCal.

Bump for some more answers

Thanks,

Jay

[Santas90Si]

Run an msd box to clear up the rich problems....cant help you anymore there. Also the cat thing sounds right

[91civicDXdude]

most "high flow" cats arent even catalytic converters, they're glass packs that bolt in place of the catalytic converter. if you have a high-flow cat, then its obvious thats the reason.

[Beater88]

Well the cat is a documented replacement for CA cars. Carsound/MagnaFlow 94000 series. I have used this cat many times and it usually works great, in other cars. It is a CA street legal three stage cat, Which is what is "stock" in the honda. It is not the cheasy eBay cats that are, as you say, bolt in glasspacks.

The only difference is I got a 2" inlet insted of the 1.5" that is stock. I suppose that it is not getting hot enough due to lack of back pressure as I have 2.25" OBX exaust. If the cat doesnt get to 500deg it wont work. I suppose that this is a possability.

I was hoping not to have to go to MSD because of expense. Apexi also has a tunable ignition and fuel curve module. It would suck to have to go to that length.

Thanks,

Jay

[dssmax]

Try wrapping the bottom half of your exhaust manifold and the freeflow cat with header wrap, make sure that you overlap it more then whats called for this will keep in the heat and warm up your free flow cat....



MAX


.

[Beater88]

Not a bad idea Max!

I think that I will try the stock cat too, Got one for free from a buddy parting out a Civic. Hope that helps. We will see...

Any more suggestions?

Thanks,

Jay

[torich]

How do you get the egr cel light to go out on the pm8 ecu? I have tried pining c8 and connecting it in the line with the pa sensor but I get a pa light then. sooooo I don`t know what to do.

Thank for your help

Rich

[Christ]

You should have started a new thread for this... instead of diggin through the archives and re-opening a 3 year old thread... and I"m sure if you search this forum for the answer, you'll find it.