vr 304 auto iac and tps issue

Wiring diagrams and questions
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chuckfinnley
Posts: 7
Joined: Mon May 20, 2024 8:02 pm
cars: vq 5l vr 5lt ute

vr 304 auto iac and tps issue

Post by chuckfinnley »

hi everyone long time lurker first time poster

apologies in advance for my novel promise its a better love story than twilight
tldr skip to last 2 paragraphs

having an issue with my vr 5lt automagic so long story long i have swapped my vr v6 to 304 auto using a vt roller motor and matching 4l60e
im running it on a vs bt1 5lt loom and vs s3 non sequential ecu the ute has a full vs s2 statesman dash including climate control level 3 cluster
technically the cluster is a vr v6 berlina one the engine loom was a used one from u pull it about 8 years ago it was a bit rough so i cleaned it up and replaced the temp sensors and drivers side earth as the pvc was cracked and missing and reconnected the injector drivers was on gas at some point and added the vt 4 pin sourcing the plug from a vr v6 o2 sensor still retaining the vs black??? 3 pin distributor plug and pulled the coil wires out away from the back of the motor and added vt 2 pin coil plug then re wrapped the entire loom
the motor and box combo came put of my vq statesman about 6 months ago where it was running and driving with no issues running the full vt dash and engine loom ecu bcm ect
now since ive put it into the vr with the vs loom it has had issues with high idle or hard shifting iac and tps issues respectively nothing new to me started with the high idle changed the iac no improvement swapped the throttle body for a spare whole lot of rooting around and find an iac the works right then the tps plays up hard shifting hanging gear shifts ect so went thru the same routine again no improvement
bit the bullet and do the inlet manifold gaskets had the motor for 3 4 years daily driven it no idea when or if they have been done
if you know 5lts you know odds on needs manifold gaskets coolant galleries where very close to worn thru
inlet manifold was a bit ugly around the coolant ports again if you know 5lts common so grab the spare vt manifold drill and tap the 1 wire temp sensor and the mat sensor and machine up a vac port for the map sensor drill and press fit that
throw it all back together same issue cant remember if it was iac or tps playing up keeps switching between shifting hard and stalling at idle and in gear throw new injectronics iac and fuelmiser tps still same issue so i have replaced the iac and tps wiring from the plug to just inside the fire wall grommet harvested from a vs v6 loom kinda pissed off at this point as ive wasted a perfectly good vs v6 loom and no still no improvement
while doing all that ive thrown spare ecu map mat and temp sensors ignition modules and coils at it cleaned up all the earth points and added the alternator bracket to body and body to ignition module checked the fuel pressure about 55psi on prime and 45-50psi idle
solid 14.2 .3 volts out the alternator so not a low voltage issue at the battery speaking of voltage the previous tps was 2v something closed and 4.5 4.7 wot havent had the mental capacity :wall: to check the voltage range on the new one yet

when its the iac playing up it will idle high around 2000rpm or it wont idle at all and it will hunt up and down wildly untill it stalls unless i hold the throttle open and it will at set speed hunt not overly wild but you can feel the engine power come and go even with cruse control on however when the tps is playing up the idle is spot on 800 850 in gear 1000 in park keep in mind v6 tacho but it will run smooth exactly the way it should even with shifting down with a little engine braking rpm bump into 1st but it shifts hard 1st to 2nd and 2nd to 3rd and holds gear untill 25 30kmph and 60 62kmph literally chirps second under light acceleration :driving:

apologies for the long winded story but i have run out if ideas and i have done a whole heap of the usual suspects as well as some of the not so usual suspects and its not exactly a stock original car so details matter hoping some one might have an idea where to look next hopefully before i rapidly disassemble it with arm strong swing press :comp: and burn the rest
regards chuck
chuckfinnley
Posts: 7
Joined: Mon May 20, 2024 8:02 pm
cars: vq 5l vr 5lt ute

Re: vr 304 auto iac and tps issue

Post by chuckfinnley »

At this point I'm convinced its a wiring loom issue hence why I've posted it in this section of the forum I'm all out of ideas on where to look next
So I'm considering converting the vt engine loom in to a vs S3 sequential have the vs V6 loom left over to harvest and hopefully some one on here can point me in the right direction to get the memcal done to vs S3 and do a vs S3 getrag as well so once I figure out the shifter linkages I can convert it to manual already have the S3 getrag loom box tail shaft ect
Reguards Chuck
brindo
Posts: 221
Joined: Mon Jun 29, 2009 9:43 am
Location: Western Queensland

Re: vr 304 auto iac and tps issue

Post by brindo »

Are there any DTCs logged?
The TPS voltage throttle closed seems a little high at 2 volts. The TPS is not one of the ones with the plastic cover on the end is it and its missing?

Can you connect up with Tunerpro and watch the TPS move from open to closed?
chuckfinnley
Posts: 7
Joined: Mon May 20, 2024 8:02 pm
cars: vq 5l vr 5lt ute

Re: vr 304 auto iac and tps issue

Post by chuckfinnley »

I don't have any software or the like to see I sued a spare TPS pigtail plugged into the TPS and into the TPS plug to give me a point to measure the voltage with a multimeter
Didn't appear to be any dead spots or voltage drops from closed to open just out side the correct range
Some times it will log a fault code but not always
Yes it's the black plastic adaptor type and yes it's in there fallen victim that one years ago haven't forgotten since to check for it
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Vrv8hz
Posts: 24
Joined: Fri Oct 06, 2017 4:33 am

Re: vr 304 auto iac and tps issue

Post by Vrv8hz »

Probably on the wrong track but it doesn't have a VS V6 TPS fitted to it does it? I made the mistake on my wifes 304/4l60e Kingswood years ago, used to chirp second real well when it finally decided to change. Throttle shaft rotates the other way from memory on the ecotec TB, sends all kinds of bad info with the wrong TPS fitted.

But then I had to go and fit a corvette servo afterwards just to get the fun shifts back.

Like I say probably not it but hope you get it figured out.
chuckfinnley
Posts: 7
Joined: Mon May 20, 2024 8:02 pm
cars: vq 5l vr 5lt ute

Re: vr 304 auto iac and tps issue

Post by chuckfinnley »

Yes I'm aware of the different TPS types
Fuelmiser Throttle Position Sensor - CTPS132 is the one I got with the light grey insert
Went on fine with the right amount of preload
VTXU8
Posts: 97
Joined: Sun Dec 17, 2017 9:12 pm

Re: vr 304 auto iac and tps issue

Post by VTXU8 »

Checked Throttle Body gasket for leaks? Throttle cable positioned correctly and moving freely? As Brindo said, 2v is high for tps in closed position. Check tps and iac plugs have 5v coming in and check output voltages.
chuckfinnley
Posts: 7
Joined: Mon May 20, 2024 8:02 pm
cars: vq 5l vr 5lt ute

Re: vr 304 auto iac and tps issue

Post by chuckfinnley »

Yeah throttle body gasket is new came with the manifold gaskets and I wiped them with a little bit of oil so they seal and will release with out ripping
The TPS input is getting 5v in at the plug
Could the trans temp sensor sharing the earth cause a voltage drop being a vt 4l60e
VTXU8
Posts: 97
Joined: Sun Dec 17, 2017 9:12 pm

Re: vr 304 auto iac and tps issue

Post by VTXU8 »

It's possible it could be an earthing issue if you are saying you have a random tps issue then a random iac issue causing a voltage drop. If you haven't already, I would be looking at map sensor too.
chuckfinnley
Posts: 7
Joined: Mon May 20, 2024 8:02 pm
cars: vq 5l vr 5lt ute

Re: vr 304 auto iac and tps issue

Post by chuckfinnley »

Yeah maybe an earthing issue inside the loom
the earth points are good I tend to go a bit over board with earthing points wire wheeling them back to bright clean metal for good connection as the current flow is on the negative
I've swapped the map sensor 4 or 5 times with spares and changed the map sensor hose for new found 1 of my spare map sensors is dead car wouldn't start at all
As you can see this isn't my first rodeo
I've well and truly had my fair share of commodores including 7 5lts and all of the problems and have always been able to figure it out between JCs forum and here pretty much every issue has been had and solved just have to look thru hundreds of threads and posts but it's there somewhere
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