3vz swap in 91 turbo, random bucking and hesitation on freeway

[Sketch_hs]

sp1 is getting 5v

what else can cause this!? its very intermittent.

Only happens over 60mph

any ideas?


on a side note what throttle cable can I use for cruise control to the v6 cable bracket

[Sketch_hs]

so give sp2 5v also? where is that located

[Paul Woods]

5v to sp1 should be all thats needed.

What makes you think the problem is related to this? it could be all sorts of other causes,dodgy fuelling,lambda sensor failure,HT related....loads of things can cause the same symptoms.

Do a fault code pull (ignore code 42) and go from there.

[Sketch_hs]

Well I managed to find a MANUAL ecu so that eliminated that chance.

Seemed to be running fine then after about 90 miles i came to a stop and she died. Was very hard to get started again.

Eventually got it started, didn't want to idle at all so i had to keep the gas down at any stop.

Driving it, it would be okay if you where VERY light on the throttle but if you went past like 10% it would cut out and loose power. Overall major loss of power everywhere.

It died a few more times on the way home. Once on a bridge... I thought I was going to die! No emergency lane, trucks narrowly missing me while I and a nice passerby pushed the junker the rest of the way.

After about 10 min we were able to start it up again, and made it the next 60 miles or so back home, just being really light on the throttle.

Got it to the garage, hardly running.

Died one last time and couldn't get it to start at all after that.

I tried changing:

TPS

AFM

complete ignitor and control modual bracket

All parts where from known working car. Didnt even try and start. yet when we check for fuel its there, injectors are working, spark is there and strong. Compression is great.

So why wont it run? where do i go from here? Need this thing running ASAP :(



So thats that.

Another strange thing going on, I notice the check engine light (already on displaying code 27) Would be brighter with no throttle applied. Push the gas harder and it gets dimmer. Floor it and it sometimes would disappear totally. Now when I was limping it home and found that cruising speed and throttle position it would stay running, the light would turn off after about a min or so of babying it. Whats the reasoning behind all this?

Anyways off to WALK to the nearest auto parts store. Only thing i can think of is that the spark is weak SO i'll next be swapping out the cap, rotor, plug wires, and the distributor for my spare

Thanks in advance,

Tyler

[Paul Woods]

ah ive just had a little light bulb pop in my head.....check your alternator main power terminal.... we have seen one with a loose terminal that caused bucking probs and a flickering ecu light,just a stab in the dark but check it anyway.

[Sketch_hs]

just code 27.

I dont know cause it really slowly went out.... like a parts failure.

Some of the parts I used had over 220k miles so i donno

If this doesnt work i'll check my wiring.

The check engine light doesnt flicker, its based on LOAD on the engine. Its totally predictable ... not like a wiring fault.

its all rather confusing :(

[OlberJ]

Aye but the more you drive it, the faster the alt belt spins and the more charge is put into the system.

Check that alt connection.

[Sketch_hs]

okay i'll check that also... didnt seem to have a charging problem... im not sure.


Now even with just the ignition turned ON the check engine light is VERY dim :(

[Paul Woods]

check your earths on the rear cam cover and the earth on the end of the plenum,add extra grounds to these if you like.

[Sketch_hs]

Okay I'll do that Mr. Woods.

At this point the injectors are NOT firing. They of course were before :/

I am still getting spark and the fuel pump is working fine. Everything else seems okay. I"ll check the grounds, ad some more and report back, STAT

[Sketch_hs]

Was able to drive it a few blocks this morning before issues again.

Here is the scoop;

When the CEL is dim the car wont start or it will die if it was running. When the CEL is bright and normal it starts up fine and runs beautifully.

I'm having a lot of trouble understanding this issue. It will not run one second and then run fine another, not touching anything or even moving the car at all.

What could this be? I can only think that the ECU is loosing a good ground or that it's loosing power.

Can anyone tell me where the ECU grounds and where it gets 12v constant, 12v ign and 5v? I would like to check all of these

[Sketch_hs]

oh and when the CEL is dim the injectors are not firing.

[Paul Woods]

an anyone tell me where the ECU grounds

i already told you,at the rear bank cam cover and on the end of the plenum on the acis bolt.

Check those out first and report back.... or do a continuity test on every BROWN wire at your ecu plugs,they should all have continuity to ground.

[Sketch_hs]

i see the main grounds on the rear cam cover.

Which ACIS bolt is it and where does that ground go to? I'm not seeing that one

[Sketch_hs]

also now i'm getting CODE 14 along with CODE 27

not sure if that helps?

[Sketch_hs]

okay on the 16 pin connector to the ecu there is a BROWN and a BROWN w/ BLACK STRIPE wire neither of them have ground.

I know the BROWN wire should be grounded. Where does this one end up?

What about the BROWN w/ BLACK STRIPE?

Thanks again everyone

[Paul Woods]

the one thats normally bolted to the end of the acis is probably on the rear cam cover as well,but the cam cover doesnt have a ground,its rubber mounted.

Most people build the v6 the wrong way and attach this ground to the rear cam cover,im guessing its attached to a bolt nearest the pulley side of the cam cover,take it off there and attach it to the end of the plenum on the acis bolt

[Sketch_hs]

yup i messed that one up. Fixed now.

It was running okay before i fixed that (for now anyways) I guess its time to put some miles on it. Hope it doesnt break down again.


any idea on that code 14 Mr. Woods?

[Sketch_hs]

just put 15 miles on it... seems okay

[Paul Woods]

code 14 is ignition signal,check the ground on your amplifier bracket,if its not grounded you will lose or have intermittent spark.

Grounds are very important on the v6 as you are finding out!

[Sketch_hs]

its grounded by the bolt and the two connectors. I'll check it over again... where are those two supposed to ground at?

Okay put about 50 miles on her yesterday everything was going fine then had the loss of power/bucking issue on the freeway.

It would loose power then sometimes come right back, other times i'd have to put the clutch in, let it fall back down to idle... then its fine....


I checked SP1 for 5v from the tps... its solid at 4.98 or so anytime the IGN is on at all throttle positions.

I was thinking is it normal to experience this ONCE then not again? Maybe the ECU learns it or something and it wont happen again after that? It did the same thing on my other v6 mr2, ONCE then never again.

Any input is appreciated Mr. Woods, thank you.

[Paul Woods]

my gut feeling is there is something not grounded right,code 14 has given us the lifeline clue.....the spark has been interrupted ,so it could be a simple ignitor fault or grounding issue.

I take it the engine only has a problem under load and never at a standstill? what i mean is does it ever miss a beat just revving it up?

[Sketch_hs]

its seems to only occur after cruising for a while.

The ignitor was swap into my other v6 mr2 to test and its having no issues so it cant be the ignitor it self. One ground from the bracket goes to the side of the front head, the other ground to the trans bolt?

I'll ad two grounds, reset and drive again i guess...

[Paul Woods]

there is another ground id like you to add just so we can rule out grounding once and for all..... if you start at your ecu plugs and measure about 12-18 inches down the loom,open it up here (remove tape basically!) and you should find a thick W/B wire thats got a rubber cap on the end of it,ground this wire.... this will override all engine grounds you have currently,so if it still has an issue it wont be an earthing one

[Sketch_hs]

okay will do Mr. Woods.

I put 4 extra grounds from the ign bracket too :)

i hope this works!

[Sketch_hs]

Didnt find that wire you are talking about with a rubber cap....


however code 14 is gone for now

[Paul Woods]

thats odd,they all have that ground,maybe its a difference in windom/camry looms that we havent noticed before

[Sketch_hs]

well this is also a US spec camry loom, 1993 4 v6 auto.

I will put over 100 miles on her today, we will see.

Thankfully I have my three free 100 miles tow per yer with AAA now :)

[Sketch_hs]

over 400 miles no issues. seems good now!


thank you everyone!

Hats of you to Mr. Woods!

Grounds, grounds, grounds!

[Paul Woods]

you're welcome bud,good grounding of the ignitor bracket and ecu grounds cannot be stressed enough,job sorted thats the main thing.