Hi

I have a 93 sidekick 16 valve and number four fuel injector all of a sudden started shooting to much gas and fouling out the spark plug. This just started out of the blue with no warning. Anyone have any idea what is causing this? I have heard it could be the computer but I dont know.

Dirt in the injector tip, best to replace it
I think these are batch fire, if not they
double fire (2 injectors) so I doubt it's
the Computer

Wild

Dirt in the injector tip, best to replace it
I think these are batch fire, if not they
double fire (2 injectors) so I doubt it's
the Computer

Wild

I think they may be sequential. They have a cam angle sensor as well as a crank angle sensor and also have individual drivers for the injectors. If the output transistor has gone s/c to gnd then it could give those symptoms. So to would a short in the wiring on the return side. Try swapping the injector for another one that will tell you if its the injector or elsewhere.

A true sequential system is rare,
it could be, but I doubt it as the
price of such a system is quite a
bit more than a simple batch or
dual channel system.

Sequential is for idle emissions,
plain and simple, there is no performance
gain from such a system, no matter
what the car makers say

Just put a test light on that inj. conn. and if it stays lit all the time you have a short to ground on the ground side. You can move the related harness to help find where.

  Kevin

Hey PPLTRACK

    XLNT tip

Zag

A true sequential system is rare,
it could be, but I doubt it as the
price of such a system is quite a
bit more than a simple batch or
dual channel system.

Not really the sensors are there and so are the drivers (I have one apart in front of my now), the rest is just in the firmware. I do agree that its just for emissions.

Rhino are you still working on that EFI
system  LOL  get a MegaSquirt, and
tweek it instead  

I agree that the Sequential system is sensors
and firmware, but the need is also the factor,
if you factor in the origional cost of these vehicles,
as well as the need to get good idle emmisions
and I don't see them building a Squential system
for the Track/Kicks

There is no way to inject the amount of fuel
needed for a proper burn in the time the valve
is open at freeway speeds, even at 3000 RPM
such a system would be hard pressed to do so

In reality a MP EFI (sequential) system turns into a
batch system at RPM, overlapping the valve opening
time to get enough fuel into the cylinder at speed

The sound is cool tho "Tuned Port Sequential injection"
must have a whole lot more HP than a simple Batch
fire system LOL

OK, I'm off the Soap Box

Wild

Rhino are you still working on that EFI
system  LOL  get a MegaSquirt, and
tweek it instead  
Wild

I'm on the Mk111 version now with a DSP and a USB interface, I have a nice Vacuum Flourescent Display for the dash too  .  The 16V board is from a dead ECU that I robbed of its case and connector. I was rather surprised to see the four seperate drivers in there although the schematic does show them all individually wired. The hardest part isn't the ECU itself but figuring out the Spanish wiring, they never released a schematic for it. MSII wasn't around when I started or I probably would have gone that way, MS didn't have enough functionality to replace the stock system directly. The electronics was pretty easy, the software was a long learning curve, I spent one year at college doing evening classes to learn how to write Windows programmes so I could interface to it without having to use a DOS programme.

Ok
    Now you got me interested...what are you building Rhinoman?

Zag

I like the dash display, I would build one
of those for the Squirrt, but the display
pannels are kind of pricey.

A in dash interface for simple adjustments
would be nice, but once the EFI is setup, there
is little need to mess with it.

MSII is an advanced version of MSI, Ultra MegaSquirt
is going to have enough functionality to run in place
of the stock ECU, including Transmission control
and Ignition, tho MSII can do ignition too

One thought, 4 drivers might be batch fired still,
just for LowZ injectors, so the drivers don't burn
up from the load, as an example the MSI board
has the option of firing both or alternating the FETs
firing, and I suppose with more CPU power you
could fire multi FETs in a sequential system, but
the CPU has too be a powerful and fast one to
process all these impulses with accuracy

Keep up the EFI work, I'd like to see what you
finish up with

Wild

Ok
    Now you got me interested...what are you building Rhinoman?

Zag

This is one of those never ending projects. I can't even remember when I started it, 2 maybe 3 years ago. I was going to do some playing with the engine so i was looking to reprogramme the ECU. I couldn't get any data for it because most of the ICs are custom made for it. I looked at the MS system but I wanted a direct replacement for the original so i thought I would build one. I'm an electronics designer but i knew nothing about FI and my programming skills were limited to DOS applications. Its really just a bad weather/bad back project it keeps getting delayed because in the time I've been working on it other stuff keeps happening. I've been made redundant, found another job, that company got taken over then moved, I moved house. I thought I had a design finalised a couple of months ago then I discovered my wiring was all different from the FSM, I still need to track down a couple of signals but its nearly there. Still if I get it finished before Ultra MS is released then I'm still ahead, lol. On the plus side I have used loads of the stuff I've learned in the meantime. I've written windows based programmes for work for testing and simulating stuff, The voltage regulation and grounding scheme has been used a couple of times and the PWM stuff is being used to control the washer pump in an armoured vehicle  . It works both ways, some of the stuff I have learnt for the ECU has been used at work, some of the stuff I have learnt at work has been used for the ECU. The serial protocol is very similar to the NMEA protocol used for GPS and naval applications, just like the gunfire control stuff I did a few months ago

Clipper4,

Try the water temp sensor, it may be faulty. To test, disconnect the sensor and run the engine. It wont be running rich anymore.
When the sensor go faulty, it will always assume the engine is cold and request more fuel to the injector.