Voltage Effected Rough Idle

[toybreaker]

It should be noted that since you're starting with a non efi car, they have probably sized everything for lower current draws.

This means the ignition switch is probably going to be overwhelmed if you try and set it up like a car that was designed around efi, as the switchgear in non efi cars is lighter duty.

Because of this, I would suggest you set-up all the hotel loads on designated relays, and use the key to only provide the signals to the relays.

Yes, starving the transistor for voltage/current could have damaged it.

Re-wiring things to provide it with clean power and replacing it will tell that tale.

I can't tell for sure, but is that a three pin relay? I am not familiar with the p/n or configuration...

I would strongly recommend you use a bosch style four pin relay when bodging things.

They generally have an antiflyback diode installed, and are fairly bulletproof. If one does fail, it's easy to find a matching equivilent unit in any town/village. They were (and still are) used in most german cars, and are fairly standardised.

Two 40 amp relays can handle everything engine related, and you can use an efi spec mpi relay to run the pump.

Be sure to draw up a digram for what you have done, and take some pictures so you will have a "road map" of sorts to guide you if troubleshooting things becomes necessary in the future.

 

[Specter]

Thanks for explaining, i used some relays i had laying around, similar to bosh style, it also had an inline fuse with it. So yes i am just using the ignition to trigger the relay, the input current for the relay comes straight from the battery, no load on ignition switch. Its all set and ready to go. Now you have said that the transistor might have been damaged, i would surely replace it and hopefully it will start.

Yeah that's a 3pin relay, i soon found out its for the the headlights.

I want you to answer one more thing please, the power transistor is supposed to be fed current through the black/white wire?

Thanks for all your help, i am almost done /ubbthreads/images/graemlins/smile.gif

 

[toybreaker]

Quote:
I want you to answer one more thing please, the power transistor is supposed to be fed current through the black/white wire?



"the" black and white wire is a bit of a dangerous thing to say. /ubbthreads/images/graemlins/tongue.gif

There's gotta be at least ten or fifteen of them in the engine harness on usdm 1g/galants and/or 2g's that share the same basic evoIII wiring layout that you are trying to duplicate. /ubbthreads/images/graemlins/wink.gif

In this particular case, you're knee deep in midstream, you've got wires running hither, thither (and yon /ubbthreads/images/graemlins/laugh.gif )...

It's a lot like roads.

The same wire goes from the battery to the relay out to the coils/transistor and then on to cleveland, detroit and points east.

Where you intersect the wire determines who's feeding who.

The possibilites are endless, and without having the car in front of me, the best advice I can give you is to consider the bigger picture.

It sounds like this is a drivetrain swap, and the car started out as a base model, carburetor equipped vehicle.

The "hotel loads" are what is carried on the wires that are hot with the ignition switch in the run position.

The manufacturers know the approximate total load that those items require, and will size the wiring and components for that load.

You're probably adding a pretty substantial change to their original calculations with this swap.

If you've upgraded the fuel pump, you could have easily doubled the current draw, and the turbo ignition set-up is a pretty decent increase in draw over the stock distributor set-up as well.

This is why I when I'm doing swaps, I use a multiple relay panel, dedicate individual fuses/relays to each purpose/circuit, and run sensibly sized wiring out to the loads.

By splitting the loads, a much longer life will be achieved for both the components and the switchgear, and it will be much easier to troubleshoot in the future.

I've always found a carefull, considered approach will yield the best results when it comes down to troublefree swaps.

In this particular case, let your conscience be your guide...

I've gotta run, so I can't look at the digrams right now...

It's not that hard to run a dedicated 12awg wire into the engine compartment to run the ignition components in parrallel to what's already there.

Just prune them off the main black white wire where that branch joins the main harness, and then connect them to your dedicated wire. Do not cut/interupt the black/white feed wire in the main harness, just prune your feeds off and connect them to your new wire. (That wire may feed other items downstream and if you cut/interupt it, something further downstream may lose it's power feed.)

Sorry, gotta go, I'll check back in later.

Good luck, and keep us posted on your progress.

 

[Specter]

Yes i am trying to reduce the load on the ignition circuit where ever possible, but i might have asked my question in correctly, by black/white i meant the wire in the 8 pin power transistor plug. Before i thought that the transistor feeds from this wire to the coil pack, but after thinking a lot with the help of diagrams, i think it does not "feeds" but rather gets "fed" from that wire. Is that correct? If so i would feed the power transistor and the coil pack from a relay, that would be a huge improvement on my ignition system.

 

[Specter]

Oh and i have set the upgraded fuel pump through another wire from the battery and activated by a switch, so that is out of the ignition system too. The only stuff running on my ignition system are the in-dash accessories and other stock things and all the relays "trigger" pin i have attached, nothing out of stock or anything heavy.

 

[Specter]

I have some, not so good news. I took out the power transistor but then i thought, why not check the input of the transistor first rather then checking another one. So i checked for the pulse at pin 10 and pin 23 at ecu, voila i had pulse. I checked it at the relative pins on the power transistor grip, no pulse there. I thought its a broken wire, so i got a new wire laid down to the power transistor, i check the pulse again at the transistor grip, and there is no pulse. I checked it at the ecu, and there is no pulse. Cranked the car couple of times but could not get any pulse. I think the the ecu wants to give the pulse out, but it sometimes does so, and sometimes cannot do so. All the wiring which i had re-done had proper current. I am thinking either:
1) Bad grounds to the ecu
2) Loose pins on the ecu connected of the grounds or the power input wires.
3) ECU Problem. ( GOD NO! The ecu board is perfect, no leakages, no smell )

What do you think?

 

[Specter]

Need help here...I rechecked everything. My ecu grounds are fine, my power wires to the ecu is fine, my mpi relay is turning on. I noticed that i am not getting any voltage on Pin 1 of the mpi relay when the ignition is on, it goes to the fuel pump terminal. And i am getting 8.5 volts positive current at pin 5 of mpi relay which goes to the pin 8 of ecu (mpi fuel pump power supply). When i turn the ignition off pin 8 is grounded by the relay.

Is 8.5 volts good to signal the ecu? Or is it low? I do not need mpi relay pin 1 as my fuel pump is independent. I only need to know if 8.5 volts is enough to signal the ecu from the relay.

Thanks!

 

[Specter]

It starts! There were 2-3 loose connections i made. Also i did not know that the ecu throws negative pulse to the transistor, i thought it throws positive pulse. That is why i could not detect its signal because it was throwing negative pulse all the time and i was checking for positive pulses. Any ways as soon as i found that i out, i hooked the same old power transistor and coil pack, started right up. The spark is very strong now, checked it before starting, before the spark used to be weak and bluish, now it is very bright yellow with good thick spark arch.
The car is standing very stable, no problems yet, but it is blowing a hell lot of smoke out the exhaust, i am assuming there is a lot of carbon on the pistons which was made due to extreme richness of a 1g maf coupled with a weak spark that could not burn the fuel. The now stronger spark is cleaning up i guess, either that or its the turbo.

Thanks again toy breaker for all your detailed posts, your kindness and all the time you dedicated to this problem, not to mention a couple of strings you pulled around here to get those wiring diagrams. Without you i would not have come so far this fast.
Thank You Sir, God Bless You! /ubbthreads/images/graemlins/worthy.gif /ubbthreads/images/graemlins/worthy.gif /ubbthreads/images/graemlins/worthy.gif

 

[toybreaker]

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