h9civic3

I have a few issues i think.

First, i turn the key to the on postion and get no fuel pump prime. This led me to check the main relay which checked out fine. After a series of other testing which i followed from a previous post from someone else, i decided to open the ecu and see if that might be the problem. This is what i found.






After tracing the burn back to the pin, it appears it is for the evap purge control solenoid valve... If this is the case, woud that be responsible for the fuel pump not engauging?

BTW the car has been sitting for a couple years. It was a project i started and lost time for. Now it is a necessity as the motor blew in my daily driver.

Any help would be greatly appreciated!

h9civic3

Also this motor is supercharged and supposedly the ecu is chipped. (I dont know how to tell) I have also hard wired a vtec controller into the harness. (Looking back now i dont think i should have). I did recheck all the wires and they seem to be where they are supposed to be.

h9civic3

After doing some more research i found out the burnt component is for the evap purge solenoid valve. Most people agree that it should not keep the fuel pump from priming, or really hurt anything for that matter. So i guess back to my orriginal problem. What is keeping the fuel pump from priming? Also, the check engine light comes on when the key is on and it doesnt go off. Any advice would help. Thanks.

TomCat39

I'd like to know where you found schematics for the ECU to know that the burnt transistor is controlling the purge evap solenoid.

I'd first just replace that transistor and go from there as it seems you have information we don't on ECU schematics.

Also for chipping obd1 ecu's they put zif sockets and a few other components into the area in red then plug the chips in there, see pictures below:

h9civic3

To find what the transistor controlled i just followed the board up to the pin. I looked in my Chilton's manual to see what that pin went to. It was the evap purge solonoid. I also found where some other people said the same thing on some other forums, which confirmed what i thought.

My ECU is chipped then. I have an SST chip with some other components as you mentioned.

TomCat39

I totally forgot all about this last time I was reading at xenocron tuning.

If the plugs are reversed (same plug style/type common error) it will blow that transistor and also prevent the car from running or I guess very poorly.

You have your purge solenoid plug plugged into your IAT and vice versa.

Edit additon: Also forgot to mention, you can buy that transistor at xenocron.com

TomCat39

After a good night's sleep, something occurred to me.

Before you just go switching plugs around, you need to test wires on the plug to pins on the ecu.

This is why, when the plugs were plugged in, it popped the transistor and whomever did it may have swapped the plugs to be proper.

Your plugs could be correct now just your transistor is popped so the ECU is missing vital information.

h9civic3

I checked the plugs and those two plugs arent even the same. It is actually the same as the map sensor plug, but that wire isnt long enough to reach the map sensor. I must be completely missing something....

TomCat39

Here is another thought, check continuity from both the mentioned plugs and the pins to the ECU to make sure the ECU plugs are pinned right.

One way to "fix" things is by repinning the stock harness on the ECU plugs.

You need to look up the pin outs but by the sounds you are pretty electronics savvy.

Your ECU is chipped so new basemaps etc, why it needed to be chipped would likely also why pins would be moved around on the ECU harness plug.

h9civic3

Ok after further investigation, i did in fact have the sensor plugs switched. However, by finding that i also found another plug (same type). It has a black/ yellow wire and a blue/yellow wire. I cant find it anywhere in the wiring diagram. Any thoughts on what this might be?

I have the IAT plugged in and the purge solenoid. I just need to know where the third plug goes. Its in the area of the throttle body...

h9civic3

Ok next question, i cant find the evap purge solenoid valve. I dont think i mentioned the motor is supercharged. Do i still have the evap solenoid?

h9civic3

I answered my own question. I found the one that was on the stock manifold in a bucket of parts i had. So my next question is, do i need it? If not, what do i do with the extra plug? Again, thanks for any help.

TomCat39

I am not well versed on modded cars. My current knowledge is purely with stock and even that is pretty naive so far.

Maybe someone else can help you out.

I know I turn to google when I want to learn the operations of a specific part. Then I can make informed decisions on it.

Also there is some critical information missing. What trim level was the 93 civic? DX/SI/CX, USDM or CDM? These details along with all the modifications are important. Engine swap is just one modification. Supercharger, what else. It's your project car, you need to provide details if you expect anyone to be able to give you accurate help.

Former User

Replace the ECU.

h9civic3

I was just trying to give the relevant info at the time to keep people from having to read so much. Thanks for all your help.

Ron, you think the ECU is shot? If so, i need to get a chipped ECU ( just basemapped before, would i be better off with hondata or something of the sort?) and also am going to need to get the car tuned. Any suggestions for either one of those?

tony_2018

Your tuner doesn't provide a backup copy of the tune to be burned on another chip?

edit: disregard, it looks like you bought the car as-is.

h9civic3

I am the second owner of this car. I bought it from my uncle stock. Everything thats done to it was done by me or someone i took it to. I didn't know much about chipped ecu's back when i had this done (still dont really) originally (3/4 years ago). im not even sure whats burned on the chip, if anything? I don't have a tuner yet. This chip was done at a guys house at the recommendation of someone from "Tampa Racing" forum. I have never had the car running properly after i put it all together. I ran out of time/money. (kids fault lol). It is now somewhat of a necessity to get it running. And i would like to do it right and once and for all.

TomCat39

I would think you could get another ECU from the salvage yard, prep it with a socket and all the needed hardware, then just move the chip over. It's the chip in the zif socket that has all the tune info.

Would that not work?

h9civic3

I guess i dont know the difference between a basemap (what i have) and hondata. Is there more you can do with one or the other? Like i said, i need to have it tuned regardless so i guess now would be the time to get the hondata chipped ecu if it is in fact better.

The motor is a D15B, AEM cam gear, jackson racing supercharger, 550 injectors, walbro 255 fuel pump, dc sport header, a vtec controller (for whatever thats worth, ive been told id be better off without it), and of course the, apparently fried, basemapped ecu.

So if anyone has any advice on the chipping of the ecu, i would really appreciate it.

TomCat39

From my recent research, Hondata s300 has a little bit more features over Crome, such as launch control, multi level boost controls. This is all geared for track use. There are other option like AEM, Neptune, eCtune etc but I have not done any research on the others as the tuners in my area are not using any of those (except AEM and certain stand alones).

Hondata s300 is also going to be a 500 dollar minimum per car for the hardware, not counting the tune.

Crome is an EEprom editor while Hondata s300 is a full EMS from what I understand.

h9civic3

So for everday street use a simple basemap that is tuned will be fine?

Also, is a vtec controller going to help with any of the tuning? Or is all the tuning done electronically?

TomCat39

Shouldn't need a vtec controller. The OBD1 ECU even if non vtec (ie P06) can be converted to vtec with just a few additions to the ECU along with the zif socket for the tuning chip.

I'm of the mind, if you have turbo/super charger you can get more out of your setup with the s300. If you are just sticking to an NA car, crome seems to be sufficient. If you get heavier into crome, the hardware starts to equal one s300, however, the hardware is for tuning, data logging etc. So it won't stay with the car when done and will be used again for your next vehicle tuning with crome. Hondata stays with the car and you have to buy another hondata for your next car etc. Crome you are only buying the chipping kit and chips. You don't even have to buy the burn2, ostrich etc if your tuner has all that fun stuff and you don't ever plan to tweak your tune outside of paying your tuner.

Really though, find out what the tuners in your area like to use as they are the ones doing the job for you on the dyno. That is really what will dictate what you need to use/get.

tony_2018

This.

h9civic3

The VTEC controller I have is able to change the VTEC engage RPM, fuel output at designated RPM's, etc. So, if getting the ECU chipped does the same thing, what good is the VTEC controller? Or, what is the difference? Im just trying to decide if i should take the VTEC controller out or leave it since its already there.

TomCat39

I've not done any research on vtec controllers but I think I can hazard a pretty solid guess.

I would think that the vtec controller is to emulate vtec operation on a non vtec ecu. Basically to avoid chipping a non vtec ecu while getting vtec functionality.

In vtec the fuel maps change, in a non vtec ecu they won't so a vtec controller will have to also implement a new fuel map while in vtec.

If you are chipping and tuning your ECU, dump the vtec controller as it's typically less accurate than doing it all with the OEM ECU. I don't believe the vtec controller takes into account engine loads and usually just purely runs by rpm. The ECU takes all factors into consideration when to engage vtec.

Also it's just more complicated and more things to have to trouble shoot if something goes wrong. Why use 3 cogs to do a job that 2 cogs can do just as effectively if not even more effectively?