[BNE] Intermittent Poor start/Rough running - undriveable

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Kain)

Sun, 23 Oct 2016 13:44:59 GMT

Thanks everyone for your suggestions, I've finally found & solved the problem. Just in case someone stumbles over this in future, the issue was a faulty distributor, and the key symptom was a check engine light on beneath 2500 RPM, and off over 2500 RPM, but no logged code. All resistance tests of the distributor checked out as per the BGB, but swapping the part made the issue go away.

Re: [BNE] Borrow a 3SGE Rev2 ECU? (twopower)

Wed, 14 Sep 2016 17:45:27 GMT

I had similar issues, turned out to be the MAP sensor, i've gone through two of them now! as Rob suggested ^ vacuum leaks from hoses are worth checking over.

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Rob)

Wed, 14 Sep 2016 08:54:35 GMT

I would be checking all your hoses had similar prob with 3sgte changed out everything to eventually find a cracked vaccum line

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Kain)

Wed, 14 Sep 2016 07:42:46 GMT

Okay, I was able to work on the car over the weekend, still no luck though. Here's what I've found:

Tried a known-good coil & ignitor (courtesy of Eric), no change.
Checked through the vac lines, no leaks or missing hoses found
Car revs easier and is less likely to want to bog down when MAP sensor is removed

I'm still searching for a MAP sensor to buy or borrow, let me know if you have one for an NA!

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Kain)

Fri, 09 Sep 2016 09:05:56 GMT

Thanks guys, I appreciate all the suggestions and input!

You're right James, but at that point the only question was 'do we have air, fuel & spark', in the initial stages of diagnosis. Fair point on the ECU as well, I haven't crossed it off the list but there are more likely suspects to pursue first - that MAP sensor code is the next on my hit list. By ignition timing I assume you mean static timing/adjustment of the dizzy - yeah that's been checked.

Reddtarga - None of those vac lines were removed, but I will check them out. I don't have much experience in telling the difference between the two, but my issue doesn't seem like a vac-leak though, more like ignition breakup/problems. Thanks for the engine manual too, I've got the gen2 version but more reference material is always good :D

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Reddtarga)

Thu, 08 Sep 2016 15:20:27 GMT

One thing I found that causes strange idling problems after a 3sge motor swap.
If any of the small hoses from the end of the intake manifold to the ACIS, as well as the routing down on the side of the intake manifold that goes to the fuel regulator valve have been removed and not put back correctly.
The 2 vacuum valves there should also be tested for correct operation.

You would need the service manual diagram to check that out.
This one-> http://www.mr2australia.com/mr2play/tm.aspx?m=87772
Look on page EG 266 and EG 269
Even though the manual is for the gen3 motor it also applies to the gen2.

Re: [BNE] Borrow a 3SGE Rev2 ECU? (James2)

Thu, 08 Sep 2016 14:39:35 GMT

That test only confirms operation of fuel pump... not whether it is creating enough pressure, or if the FPR is doing its job. Not really a fan of that test! Surely he had an adapter that would have allowed him to plumb a gauge to read the line pressure.

You can't always see the capacitors failing on an ecu. Unless you try a known working one of the same part# you haven't 100% eliminated it as a possible failure mode.

has ignition timing been checked?

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Kain)

Thu, 08 Sep 2016 14:14:03 GMT

My mechanic did with a dodgy test - he cracked the banjo bolt on top of the fuel filter, and when cranking there was enough pressure to have a decent jet of fuel spray out.

I like your method much better, to be honest :P

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Carmikey)

Thu, 08 Sep 2016 12:31:29 GMT

Kain,
Have you tried testing & seeing if you have or are getting fuel from pump?
An easy way to confirm, you can loop a wire from the FB to the B+ (same place when you loop to get fault codes) & then switch on ignition, as soon as switch on key to ign, you will hear the FB activate, (buzzing sound), if that works, proceed & crank it over & see how it runs.
Once it is running you should be able to disconnect the loop wire... then see what happens ;-)

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Kain)

Thu, 08 Sep 2016 11:17:39 GMT

Thanks Tony, all good ideas! Most of that I've checked - it's got a new dizzy (I rebuilt mine and the NE coil lost a connection somewhere " />), plugs have been checked, timing belt tension is good (was an issue before, brand new tensioner was DOA), cam timing has been checked. Just got to sort the fault code, all indications are that the sensor is faulty.

5SGTE, great idea, I never thought to actually look for a failure mode in the ECU. I've just pulled it out and checked it - I've never seen a 26yr old PCB so spotless! All components look perfect, and no flaws in the board or coating.

Thanks for the ideas guys, keep them coming!

Re: [BNE] Borrow a 3SGE Rev2 ECU? (5SGTE)

Wed, 07 Sep 2016 17:07:42 GMT

Pop the cover off your ecu n check the caps are good. Easy to do before replacing a heap of potentially unneeded parts.

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Guest)

Wed, 07 Sep 2016 15:00:21 GMT

Had a similar issue with idle, fixed by removing the sensors from the coolant neck in the engine bay, wiped the end with smooth sandpaper to refresh the surface and reinstalled.
I also cleaned the throttle body (spray cleaner), as well as dialled up the air screw in the throttle body so when warmed it would sit on about 950rpm.
I think your issues are more involved.... possibly refreshing rotar and distro, sorting out your fault code, general service items (spark plugs, check timing / timing belt (that timing belt is firm and has not stretched or the pin not pushing to create correct tension)....
Good luck,

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Kain)

Wed, 07 Sep 2016 13:38:46 GMT

Thanks Eric, swing me a PM when you've had a chance to take a look!

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Eric)

Wed, 07 Sep 2016 11:40:03 GMT

Kain

Anyone have any ideas, or has a known-good MAP sensor and/or ignitor & coils package they'd be willing to lend me? Thanks for any help you can give!

Hi Kain,

I believe that I have a map sensor, ignitor etc at home. I'll have a look for you tonight.

You're welcome to borrow them and if they work you can swing me some cash for them, say $50? they are no use to me.

I'm located on the south side

Re: [BNE] Borrow a 3SGE Rev2 ECU? (Mrskylighter)

Wed, 07 Sep 2016 11:02:36 GMT

My suggestion is to try a different ecu with the correct part number in your car to see if there is any change. You could also take the cover off your ecu and check for blown capacitors.