[RBwonga]

Hey Team,

Car is a 94 Sierra with a G16B 16v.

Please note, I'm not with the car, so I'm unable to test things before the weekend.

Over the weekend, the check engine light flicked on while I was driving up the hill, didn't seem to lose power, as soon as I backed off, the light went away, Didn't think too much of it. 10-15 minutes later, it came on and stayed on, car was definitely down on power, couldn't do much more than 60-70k's, managed to get back to camp, then disconnected the battery for the night. In the morning, she turned over for a few seconds and then stalls, if I try to give it some throttle when it's on, it dies almost instantly.

There is no 02 sensor in the cat, so doubt it's that. I'm leaning towards map sensor. checked the hoses, no blocks/kinks.

I couldn't find that consult cable thing in the engine bay or dash.
I also came to assumption, because it has a Map sensor, it's from a Baleno.

what are your thoughts, as I'm very new to Suzuki's.

[fordem]

Do you normally disconnect the battery every night? It sounds a little unusual to me.

You say there is no O2 sensor in the cat, there isn't usually one in the cat, it's usually before the cat, and if the vehicle is OBD2 there will be a second one after. I'm going to go out on a limb and say it would be extremely unusual to have a cat fitted and no O2 sensor, and if there was originally an O2 sensor which was removed during the swap, someone did something to prevent the check engine light from coming on.

Here's where the challenge lies - we're not familiar with the vehicle and how the swap was performed, you appear to be in a similar situation, so nobody knows what is really going on - that said - most EFI systems, if the battery is disconnected over night, will misbehave when first started after the reconnection, until the ECU relearns the quirks of the engine.

So - if I'm right in assuming your car has a complete OBD2 system then all you need to do is drive it gently for a bit and it will sort itself out - if I'm wrong, then we're going to need to get more details. Some of Suzuki's OBD1 systems didn't use an O2 sensor (and didn't have a cat) and have no relearn requirements.

[MrRocky]

Blocked cat
Fuel filter/pump
Coil pack

[Gwagensteve]

I don't have a Baleno FSM handy but I don't think any of those things would throw a trouble code. (i.e the check engine light wouldn't come on)

[MrRocky]

I think you have to take the check engine light with a pinch of salt on those conversions especially when it coud be wired to oil pressure or anything else by the orig installer

[RBwonga]

So I have managed to find the diagnostic plug and get a read out of which engine codes it's throwing up. So I've gone through the manual and I have checked that each connector is getting correct voltage, but I'm unsure on how to check if the sensor is functioning correctly. I thought it would be unlikely 3 sensors would go at once? Or maybe 1/2 were hidden until the last one came up and made it stall while driving.

ECT sensor
IAT sensor
MAP sensor

[fordem]

First - I suggest you give us the codes you got.

Second - the ECT & IAT sensors are essentially resistors so when you say you went through the manual and checked that each connector is getting the correct voltage, I'm inclined to ask, what on earth are you rambling about? Voltage? So, rather than I appear to be rude, I'm going to suggest that you tell us what voltage you measured and exactly where & how you measured it.

By the way - we still don't know if we're dealing with an OBDI or OBDII vehicle - so that is something else you need to tell us.

Remember this one thing - we're not there looking over your shoulder, we don't know what you're doing or how you're doing it - and we can't help you when we don't know what we're dealing with.

[Gwagensteve]

fordem, I've spent hours on FB messenger going through the issues with RBwonga's car. He has an FSM and I've been working with him to understand how to check the function of each sensor (the FSM is excellent in this regard) but I think beyond his ability.

I'm not sure how to help further.

[RBwonga]

Thanks for the replies. I wrote this last Saturday night when I was trying to figure it out. As I've said many times, when it comes to electricity, it is definitely not my strength.

[RBwonga]

Just to add to this thread.
I am still learning when it comes to electrical, so forgive me if I brush past the facts that need to be given.
I get by when it comes to replacing parts or fixing, but when it comes to fault finding, I’m clearly no good at it.

Indeed it is beyond my abilities, that’s why I have sought help from others, as you may have noticed this is in the “noob talk” section.
If you should feel the need to not help, or get annoyed when I’m asking questions that may seem silly or easy to you, it’s because I do not understand properly, further explanation is sometime needed, hence why I’m asking and trying to learn.

Thank you all for your help and input.

[MrRocky]

Id focus on the symptoms of the issue, dont be so caught up on the codes. Perhaps if it was still in a baleno the codes would be more relevant

[Gwagensteve]

How do you figure that? The ecu doesn’t know it’s not in a Baleno any more. It wasn’t throwing codes, now it is.

[MrRocky]

The comp wont always throw the same codes, ive had them throw bizzare codes plenty of times from vacume leaks to dying fuel pumps.
The code isnt the be all and end all of diagnosing a simple efi system. Normally its a 5 min job
Hunting idle can throw map sensor code but can be as simple as minor vacume leak, coilpacks can be no code at all and only fail when hot.

[MrRocky]

No 02 sensor seems like a good place to start
Then id be looking at fuel delivery and cam/crank sensor next

[fordem]

If it doesn't have an O2, shouldn't there be a code for that? Unless it's one of the early EFI units than never had an O2 sensor (I don't know if Australia got those).

To me step one is always going to be figuring out what we're dealing with.

[Gwagensteve]

It has an 02 sensor. Diagnostics are working, I suspect a poor ground, 5V supply or other wiring issue

[fordem]

Which takes me back to - what do the diagnostics say?

ECT, IAT & MAP - but - what are the codes.