jtgh need your help

[shackwrrr]

well I got my kick running. I put new caps in the computer. I got the computer installed all good kinda. well it ran great for a little while. well now its messed up. I pulled the codes. I get 22-34-53 so It seems I dont have a 5v ref I dont have mt dvom with me so that sucks. BUT I can unplug my battery and reset the ecu AND unplug the MAF and it starts up and runs fine. then shut it off and then start it again and It wont idle, and it wont take throttle. What is a common problem that would cause me to loose 5v ref?

[jtgh]

I dont have a 5v

you lost that ? how do you know? with no VM
ouch 53 !!

that means, in some cases. or power overload. like 5v? B6 pin .
that you have the Calif. ECU plugged into a federal harness. (8v only) , << ignore sorry
that is bad but here is fix.



simple , just unplug all things connected to the 5vref pin.

TPS , gray/red
and TPS return Blue/white.

if you step on gas pedal and 5vdc does not return then the blue/white is not shorted.

http://carfix.stufftoread.com/ECU/92...-size-huge.png

full size, save it and view ,rescale it, print it but it is High reso.


the maf , i think needs 5vdc to be good inside the ECU.
I found that out on mine when i traced 5vref circuit into ECU.

disconnect TPS.
key on , measure, 5v at gray/red, if still not 5v.
then that wire is grounded or the ECU 5v regulator is bad.

i may be able to point out that part.

yes, i can. replace D107 on the board, (its polarized )
buy a: 1N4733B
this is a 5v Zener diode.
make sure trace from it to B6 is not burnt open. seen that 2 times.

let me know how you do.

Originally Posted by shackwrrr

well I got my kick running. I put new caps in the computer. I got the computer installed all good kinda. well it ran great for a little while. well now its messed up. I pulled the codes. I get 22-34-53 so It seems I dont have a 5v ref I dont have mt dvom with me so that sucks. BUT I can unplug my battery and reset the ecu AND unplug the MAF and it starts up and runs fine. then shut it off and then start it again and It wont idle, and it wont take throttle. What is a common problem that would cause me to loose 5v ref?

[jtgh]

53 can be :
bad power
noisy power.
bad grounds.
bad memory.

I think it gets set if ecu crashes too. ( gets lost)

but that 5vref. can surely set that , in theory.

interesting,, ( id test that theory but shorting 5vref is very risky , im chicken)


on the 8v it burns a trace.
on 92-95 ecu not sure if grounding out 5v , will do phyical harm
on my 96 , there is a protection resistor on it.

[shackwrrr]

well I dont know if I have 5v or not I live in the middle on nowere and have no source for a meter till tomarrow. I was just guessing that it had no 5v because of the codes

[shackwrrr]

I think I might have something figure out. The main relay and fuel pump relay are quite hot. The fuel pump I installed happens to be a hefty 255lph and 125psi dead head pump. do you think that it could be drawing too much juice? Because if its drawing that much then the ecm isnt seeing what it wants on its 12v inputs. I may give the fuel pump relay its own power source tomarrow to see what that does. I should be able to find a dvom tomarrow too.

[jtgh]

that pump is way bad, it will over load the Fpreg
sorry didnt know you, had non oem critical parts on system
im asleep......

sure its overloading fpreg, and causing huge overload on injectors and all.
you need a fuel pressure guage.

and the pump will draw tons of extra current and the fp relay and Main are wired in series and will over heat them both. doom. certain.

bigger is not better.

to handle the huge pump you need a big regulator and huge return line.

that poor motor,is like hooked to fire hydrant.

Ever heard the joke about the dodge dart and the Jeto Pak.(booster rocket)
see urban myths for a laugh.

cheers.

[jtgh]

if you disagree , then tell us how much fuel the FPreg, can flow and not be overloaded.?

bigger is not always better, despite , the 1am TV ads.

hahahahah

the parameter is worse case maximum flow rate, at cold temps.
the pump runs full time running motor, so only the FPReg can hold pressure at spec.!
if you go over spec fuel pressure, the ECU can not regulate fuel. (it works from constants in memory)

the Injectors are rated at a specific fuel pressure.
changing parts and not fully testing the 3 pressures, static, running, and dead head , invites unpleasant surprises.


question. is that an external pump?

any other non OEM mods to motor.?

http://carfix.stufftoread.com/INJECTORS/mpi.JPG


on other point.
the FPreg is designed to regulate with a stock pump , using the vacuum of the induction .
it compensates for altitude.
and the net result is the pressure across the injector remains constant at all times.
if you mess up that balance, bad things happen.

[shackwrrr]

I bought the pump because it was 100 times cheaper than the stock pump and with a $20 suzuki you kinda dont want to spend 200 on a new pump this one was 20 dollars brand new its in the tank.

I can mess with the pressures later that shouldnt make the computer throw 53.

I added a new power line Just for the pump and that took care of codes 22 and 34 so the sensors are talking now.

I just need to figure out that 53 code.

[shackwrrr]

well I got myself a meter from sears today. I added a extra power wire just for the ful pump and That solved the 22 and 34 codes. I have 5.04 volts at the computer and at the TPS for ref. I Checked every pin on the computer thats supposed to have batt+ and they all have the 13-14 volts EXCEPT the brown wire coming from the noise suppressor it has about a volt less. I have also re replaced the main power capacitor just to make sure.

Right now I can pull the batt term and clear the codes. It will start up and run perfect and set code 53 within 5 sec. It will continue to run great for as long as I want but once it gets warm it restarts but runs like crap then if I reset the computer it starts all over.

[jtgh]

great work !
the pump is bad news. Rock auto has dirt cheap pumps that work.
on the order of $47 as does, Fleebay. (pump ,not RACK)

the 53, is the most obscure error.
it can be many things,
the ECU has a special sensor ground that if over loaded might set that code.
but I ask you,
what PN ecu are you running.????
there is one model that is California only model.
there are manu ECUs from 92 to 95, AT,MT, Fed and California models.
yours should be dash 58B30 if FED, and 58B50 if a california car.
the smog sticker under the hood says.....?

now if you put a calif. ecu in a federal body , you may get code 53.
or the ECU is just bad.
I can send you the FSM flow chart on 53 , i have it.


smog sticker
mine says
this
http://carfix.stufftoread.com/my96-16v/EPA-smog-tag.jpg

it does not say California nor the words C.A.R.B anywhere so that means it is FEDRAL48 car. that is the rules in 93. there are 2 ECUS , one for Fed48 and 1 for Cal. trannys same.

sadly ecu is marked on top not bottom.
cheers