VP V6 Probelms

[discostuee]

Hi all,

I have put a vp and t700 in my 4runner., its been there for a while but lately its been acting up. It starts ok and drives ok even when warmed up. But when hot when i turn off the engine and restart it runs like a bag of ****e. it stalls etc, once its been driven a little its ok again but then when its turned off it stalls and surges. Any ideas my fellow experts?
What ive done...

Replaced plugs,
New oxy sensor,
complete different throttle body with tps and iac all cleaned.


Can someone tell me also what the resistance of the Spark cables (HT leads) should be and if there is a way to test the coil pack too.

thanks in advance.

Stuee

[88GreenVN]

Hi all,

I have put a vp and t700 in my 4runner., its been there for a while but lately its been acting up. It starts ok and drives ok even when warmed up. But when hot when i turn off the engine and restart it runs like a bag of ****e. it stalls etc, once its been driven a little its ok again but then when its turned off it stalls and surges. Any ideas my fellow experts?
What ive done...

Replaced plugs,
New oxy sensor,
complete different throttle body with tps and iac all cleaned.


Can someone tell me also what the resistance of the Spark cables (HT leads) should be and if there is a way to test the coil pack too.

thanks in advance.

Stuee

How old is the CAS?

[discostuee]

sorry for seeming stupid but CAS? it rings a bell but dont want to give you the wrong answer.

[Morton]

Crank angle sensor, on the side of the harmonic balancer on the crank pulley

[88GreenVN]

sorry for seeming stupid but CAS? it rings a bell but dont want to give you the wrong answer.

As MORTON said ^^^ - they (CAS) can play up when they get hot.

But so can many things. If it's long time old or unknown, it may pay to replace it.

Is the ECU putting out any error codes?? This cn sometimes point you in the general direction of the problem.

Other things it could be is the coils/DFI unit or even the ECU itself.

[discostuee]

I have no idea regarding the CAS, is it a easy thing to change?
Also how would i test the coil pack? i dont want to buy another one and find its not that.

The ecu i replaced on Saturday with another spare i had and its exactly the same.

Thanks

[88GreenVN]

I have no idea regarding the CAS, is it a easy thing to change?
Also how would i test the coil pack? i dont want to buy another one and find its not that.

The ecu i replaced on Saturday with another spare i had and its exactly the same.

Thanks

The CAS needs the harmonic balancer taken off for the CAS to be replaced and it also needs to be set just right else the balancer will chew it up.

Coils will get worse over a short time and start to play up all the time.

DFI also will start to cause the car to stall.

The CAS will play up most when the car gets hot and slowly got to no go at some point.

There is a thread on this JC site that tells you how to test for ECU codes - just cant find it right now - gotta go to work.

Hope this helps and Good luck.

[discostuee]

ok i did the error code.
I got 2 codes.

2-4 which i read is VSS

4-2 Which says loss of communication of dfi but could be many of things.


any hints. Ive just ordered a new CAS which ill replace at the weekend and ill also try borrow a coil pack from a wreckers i know for a couple of days before i change the CAS so i know if it was that.

[Pub247]

clear your error codes by removing the fuse or disconnecting battery and try it again ( after taking it for a spin). DFI module could be your problem sounds like an earth or some wiring connection take the dfi off and clean the earth and plug

[Pub247]

remember you'll likely need a puller to get the balancer off also theres a couple of different cas so if you know which series/year model or your engine number with you

[discostuee]

Update to Saga.
I borrowed a coil pack (VS) from a wrecker and when engine was hot turned it off and started it, its coughed and spluttered. i immediately swapped coil packs and started it again ,still did exactly the same, I then unconnected battery for 1/2hr then started again still rough and the comp spat out the 4-2 error again but no VSS (probably because i didn't move anywhere) but the VSS isn't my issue at the moment as i think i know what that is.

Ok any one point out any other bits i could eliminate before i do the CAS at the weekend?

thanks for all that's helped so far.

[VrWagz1]

I'm only clutching at straws here but wouldnt be anything like map, maf, oxygen sensors causing such an issue. Have you got the cable to hook it up to your laptop to look at all the diagnostic stuff to see whats happening.

[discostuee]

I have the cable but cant seem to get it working, tried many of ways on laptop and home pc but nothing still. it might pay to take it somewhere perhaps with one.

[discostuee]

Ok ive just changed the CAS and reset the ECU and would you believe it, i started it up works fine, let it warm up, turned off, started again and off it goes doing the same thing, almost stalling and running like ****e. I did notice when i revved and held it around 3k it sounded like it was intermittently missing.
Ive replaced plugs, ecu, coil pack, IAC, TPS throttle body and now CAS...


Any other suggestions

[discostuee]

^^^^Bump ^^^^

[88GreenVN]

Man thats the same list of things I've changed.... I think alot of the bits tend to get tired and not work as good as they should.

How old are the leads? - It idles good now when you first start it? but gets wobbly when hot?


And are all the earths making good contact?

[discostuee]

All the earths seem to be ok, i cleaned and reattached them, And yes, when cold its sort of ok, but is a bit rough idle,. but ok, when it warms up its ok too, but if you turn off then on when hot it almost stalls and lacks any power for about 10 mins then is back to ok again

[88GreenVN]

A no cost thing to check is the pins connectors on the DFI connector. Sometimes the tube type pins can open up abit. Close em with a pair of pointy nose pliers so they make good contact. Long shot stuff - but you have done all the most probable stuff already.

[VrWagz1]

Have you got decent fuel pressure, and did you have any crap in your tank that could have clogged injectors or fuel filter.
To me it sounds like it can be 3 things, timing, low voltage on plugs, or fuel. By doing the cas and coils you can say you may have elliminated the first 2. If you havnt already id be putting a gauge in to see if your running good fuel pressure, and then pulling injectors to make sure each one is misting nicely.

[discostuee]

thanks fort that,
is there a tutorial on injector testing? and what seals would i need to replace?
Would the injectors cause it to stall and be sluggish only then restarted when hot?

[VrWagz1]

I dont know that i would be looking directly at the injectors just yet, but heres a theory on fuel pressure. If pressure is low for some reason (eg, blocked filter), it may run ok when cold because its injecting for longer to get more fuel in cause the motor is cold (efi version of the choke), therfore it will get enough fuel to run. But once it gets to running temp and goes back to shorter fuel shots then it may start to starve and run sluggish and be hard to start.
Are you running the standard 4 runner fuel pump or somthing different. If its the standard pump it may not have enough flow or pressure maybe.
If you are runnning the old pump and wanna try a standand vp pump(if you have it), you can run it in a bucket of fuel and run some hoses to the injector rails.
One last thing is maybe the fuel regulator is blowing off to early and may need replacing. As it will never hold enough pressure to inject enough fuel.
But this is all just me thinking out loud. see how ya go

[discostuee]

Ok i changed the map sensor today and still the same.,

Im finding after i listen carefully that its randomly misfiring and when i pull off it feels like its holding back then all a sudden it shoots off and goes normal.
It aslo surging a bit too.

[tycho89]

Fuel pressure reg?

[discostuee]

ok another trip to the wreckers, good job its only around the corner, This should run like a dream when its done as ive almost replaced everything bar the engine itsself, lol

[88GreenVN]

ok another trip to the wreckers, good job its only around the corner, This should run like a dream when its done as ive almost replaced everything bar the engine itsself, lol

Yep thats what I ended up doing and well the wagon dose go very well now and returns great fuel economy as well. I also have a spare fuel regulator & IAC valve as they were not the problem.

Accually I have half a VN in the shed