98vtec

I have had to run a stock p28 to get my car home once upon a time a long time ago when it was completely stock. Ran fine driving it normal. I could feel it go lean if you give it more throttle needed than just normal driving but its not going to "kill" the engine just idling or driving under 2000-2500 rpm. would i endorse doing it? no, but when in need.....

holmesnmanny

run a compression test

David77

I did run one. I'm getting like 216 on all 4 cylinders Dry. But it's weird. I'm going to just have to recheck all the work on the swap. I normally run a p28 chiped. But I don't I don't get why the code is happing when I run the obd2 ecu

holmesnmanny

wuts the ecu number

David77

the p28 has a base map on it. And the obd2 is a p5m-Lo3. And i have a p13-L10.

holmesnmanny

That ecu is for the 97-98.

http://www.hondapartscheap.com/oem-p...ne/37820p5ml03

What year is your car ? I thought it was a 2000 ? Do you have an obd2b to obd2a conversion harness ?

Those distributor sensors are very very finicky. I would think with them being cracked that you should either get another distributor or at the very least swap out those sensors.

holmesnmanny

Also you can't just swap go back and forth from obd2 to obd1 without having to swap out the distributors so something is going on there. Even if you downgraded you would need to swap distributors and use some sort of distributor conversion harness...something that rywire sells. If all you're doing is changing out ecus then that is your issue you need to start there in the distributor area.

In obd1 cars the crank sensor is in the distributor and in obd2 cars it moves to the crank and they add the fluctuation sensor as well.

David77

So what your saying is that I need the obd2 dizzy and obd2 ECU, the one the has the same code that the dealer say is for a 2000 base prelude. To be able to run the car stock so I can pass the smog test? Because the person before me did all the engine work. I'm just trying to figure out all their mess ups. He hard wired the wires from the crank sensor to the distributor, hardwired that in so it looks like it's still using the OBD2 harness.
Right now I have a P5P-L03 and a TD-61u dizzy. Ad I'm getting thoes codes. I also have a TD-77 out of a 94 accord.

thirsk66

iTrader: (2)

Your issue lies in the use of the hardwired crank sensor to the obd1 distributor. You will need to check the hardwired wires for the crank sensor that runs to the distributor, there must be something that isn't wired in properly/missing. Or you can use the td-77 distributor which is the correct obd2 dizzy that comes with the 97-01 preludes and buy the correct oil pump with the crank sensor that mounts to it. Your car should run better either way you go about fixing this issue.

holmesnmanny

The td-77u distributor is not from a 94 accord, it's for your original motor.

http://www.hondapartscheap.com/parts...istributor-tec

There was no point at all for him to rewire anything. In stock form he woulda just needed to move the crank timing pulley and balance shaft pulley, along with the crank and fluctuation sensor assembly over to the jdm motor.

Also, the crank sensor wiring, if ran to the distributor, needs to be shielded because outside interference will interfere with the signal that is being relayed to the ecu. This could even be what's happening, I'm not sure. When people do swaps and wire in the knock sensor, that wiring needs to be shielded. It's the same idea here.

I would put the wiring back together and source the parts I said needed to be put at your crank. In order to use that ecu you need an obd2b to obd2a conversion kit. I'm assuming you have one now. Or you can source the L05 ecu but you will need to flash it.

Just to confirm, can you clarify which chassis your car is ? ie..what year is it originally ? I'm going by 2000 but you haven't stated plainly I think.

117

I've run a P28 NepTune Demon ECU on my 1998 base model Prelude with no problems; used the OBD2 distributor and crank sensors without any issues. None of the wiring in the engine bay was changed; just used an OBD2 to OBD1 adapter, and had the ECU tuned by Tony @ T1 back in 2007-ish. He's tuned it a number of times since then. The only problem is that you cannot adjust cam timing on the exhaust cam. Moving the cam timing causes the distributor sensors to get out of sync with the crankshaft sensors (the OBD2 distributor on the H22 is not adjustable like the OBD1 distributors) and causes a CEL.

holmesnmanny

ok i see wut ur saying but it sounds like it has to be tuned correctly and odds are its not

thirsk66

iTrader: (2)

I agree with you holmesnmanny....David77 should go back to how a usdm h22 came, just take your jdm engine make it all obd2 with the correct timing gear, balance shaft gear and put a usdm oil pump on with crank sensor, plus put the td77u dizzy on and problem is solved. It sounds like alot of work because it is but its well worth the time and money once its finished.

David77

[QUOTE=holmesnmanny. Just to confirm, can you clarify which chassis your car is ? ie..what year is it originally ? I'm going by 2000 but you haven't stated plainly I think.[/QUOTE]
The car is a 2000 base, that what i got when i put the vin in on a honda site. So the chassis is a 2000 base. Im kinda new to ludes.
so if i went all back to usdm timing gear, balance shaft gear and put a usdm oil pump in with crank sensor, plus put the td77u dizzy. And then use the P5P-Lo3, i should have no problem. but what if i need to go back to the p28. will i need to redo every thing?

117

Like I was saying, I ran a 1998 OBD2 USDM H22A4 (the one that came in the car) using a NepTune P28 ECU. NONE of the sensors or wiring (other than emissions related stuff, as it was a full time track car) were altered on the engine or engine harness (i.e. OBD2 distributor, OBD2 oil pump with crank sensors, etc). The P28 ran the engine just fine. In fact, made 216WHP with all OEM internals (although the engine was rebuilt for track use). The only wiring modification was to use an OBD2 to OBD1 adapter harness for the P28.

The head was milled quite a bit, so the cam gears were adjusted so that everything lined up at TDC and it ran like a top. When we tried adjusting the exhaust cam, the ECU didn't like it because the signal from the distributor was out of sync with the crank trigger signals.

holmesnmanny

I guess the OP just needs to put it all back together and use the obd2 to obd1 conversion harness and be good to go. The key is sourcing those parts.

thirsk66

iTrader: (2)

You will be fine running those parts that holmesnmanny, 117, and myself have advised and listed for you to get. I myself am running the same parts: usdm oil pump, crank sensor, td-77u dizzy and a p28 chipped ecu with the obd2a to obd1 conversion harness. I also run my P5M-L03 ecu that came with the car and it passed smog awhile back on my jdm h22 euro-r.

So to clarify for everyone you are trying to just have your car pass emissions in your state of Washington? And the only issue you are having right now is that the codes for misfire are still popping up using the p28 ecu or a different computer? And I read that the only issue with the p28 is the idle is off, have you tried adjusting the screw on the throttle body and seeing if that helps?

Also you have ran a compression test with good results, so my next thing to ask is have you physically pulled off the valve cover put your #1 cylinder to TDC and checked all your timing marks to see if they line up correctly? If your car runs poorly I would think the timing is off a bit, or your issue still lies in the poor wiring the previous owner did for your crank sensor to your distributor. Lets get to the bottom of this issue so you can pass smog without issue and put that p28 ecu to some good use that you paid money for.

David77

Okay, then i'll do that run thoes. Well this year i wont but next year, i'm moving to a state that it will need to pass in. And when i ues the p28 the only problem is the idel surge. but i had Justin rechip it so it has the EDl on it so its running good. But the codes i get are when i ues the P5M-Lo3. Yes here in Washington its kinda cold right now. So ill double check the mechanical timing soon. But on the note of the going to all USDM oil pump, timing pulleys. As i looked at them today, they seem to me, that they are right but i cant say for sure. But today i ripped the obvious wires that looked like he might have touched, and from what i can determine it looks like he took the wiring harness from a 92-96 vtec that works with the TD-61U and wired that in, and it loks like the crank sensor is a part of that harness. And i looked at the two dizzys the TD-77U and the TD-61u and i dont see how the crank sensor is integrated. there is no wires to tie into. Like I said I'm new to preludes. So my best bet it to to get a all usdm h22a4 and swap it all back.

David77

Okay, this is an update to the last comment i posted.

So, im just going to get the parts that you sugested, seeing as i cant find an all usdm h22. But my only question is would the jdm oil pump have the bolt hols for a crank and TDC sensors? Because i pulled off the timing belt cover and saw the two places that they go. I only ask because i don't want to buy an oil pump if i don't have to. But the balancing pulley is not the right one, it has no points for the TDC to go off of.

holmesnmanny

I wanna say they don't but I'm not certain. You can always look for yourself. Feel free to report back.

thirsk66

iTrader: (2)

No the JDM oil pump will not have the mounting holes for the crank sensor, hence the reason why you buy the USDM oil pump.

David77

Okay, so i finally got the time to order the parts you suggested i would need. And today i put the pulley on and the sensor. But i have no ides on how to wire the dizzy in. So if any one has a 97-01 prelude, could you add a pic to the post to show me the colors on the chassis to the TD-77u. Or can help me figure out how to wire it in that would be awesome. Thank you.

98vtec

Rywire makes a plug and play distributor conversion harness.

David77

The owner before me hacked the wires to a connector for a TD-66u. So do they make a harness for that?

David77

I finally got it to work. Yeah!!! Think you, to all that help me during this headache