Revs rise when drive engaged
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
Revs rise when drive engaged I posted on the auto trans section, and from the responses I've received so far is that my fault lies with tuning, hence I've posted here as possibly being more appropriate.
Link to problem:
https://ls1tech.com/forums/automatic...-selected.html
Basically, the car idles at 500rpm nice and clean, but as soon as drive or reverse are selected the revs increase to the point that the car is hard to hold on the brakes. Engine is a cutout 98 from an F body Camaro with complete standard loom and ecu. Vats have been disabled by a programmer some distance from me using an EFI live scanner, plus I asked for rear O2 sensors be deleted. I also gave them rear axle ratio (3.1 - 1 - Ford 9inch with Tru trac diff) and the diameter of tyres - 26 inches.
As LS1 motors aren't too common in my location I'm needing advice as I can't drive the car safely with it doing this. Car is a 1950 Morris Minor which weighs around a ton.
Cheers in advance,
Pete
Link to problem:
https://ls1tech.com/forums/automatic...-selected.html
Basically, the car idles at 500rpm nice and clean, but as soon as drive or reverse are selected the revs increase to the point that the car is hard to hold on the brakes. Engine is a cutout 98 from an F body Camaro with complete standard loom and ecu. Vats have been disabled by a programmer some distance from me using an EFI live scanner, plus I asked for rear O2 sensors be deleted. I also gave them rear axle ratio (3.1 - 1 - Ford 9inch with Tru trac diff) and the diameter of tyres - 26 inches.
As LS1 motors aren't too common in my location I'm needing advice as I can't drive the car safely with it doing this. Car is a 1950 Morris Minor which weighs around a ton.
Cheers in advance,
Pete
If the idle parameters weren't altered, you have a park/neutral switch, or it's wiring issue. It should not idle at 500 in Park or Neutral, but only when in gear. Hook up a scan tool to verify the PCM actuallybknows when it it in park. Probably thinks it is in gear when in Park, and in Park when in gear.
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
Thanks for that info. Park/neutral wire to the ecu/pcm isn't connected at the present - just the one on the lokar lever to vehicle wiring (inhibitor switch). Will I have to connect both a park and a neutral switch to the lokar system, or would just a park suffice?
Sorry if some my terminology is a bit alien, but hopefully we'll get there.
Here's a link to the build of the car for general interest (lot of reading and pics):
http://mog.myfreeforum.org/about1082.html
Cheers
Pete
Sorry if some my terminology is a bit alien, but hopefully we'll get there.
Here's a link to the build of the car for general interest (lot of reading and pics):
http://mog.myfreeforum.org/about1082.html
Cheers
Pete
Park would be better than nothing. I would not expect it to speed up in drive, but try to maintain the same RPM. What we sometimes see is stalling when put in gear. I'm not sure what you have going on.
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
I've still got the same problem with the revs rising to just under 2000 when either drive or reverse is selected. This is despite having made up a switch to tell PCM if in neutral or park. Revs take a while to drop back to 500 when put into neutral and park from drive, but it then idles smoothly at this level.
This glitch is all I need to finish on the build, but it's too dangerous to take out on the road with it like this to test things further - any ideas folks?
Cheers
Pete
This glitch is all I need to finish on the build, but it's too dangerous to take out on the road with it like this to test things further - any ideas folks?
Cheers
Pete
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Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
Codes pulled today are
PO 405 - egr signal low (removed by EFi live tune some time ago)
PO 449 - Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
PO452 - Evaporative Emission Control System Pressure Sensor Low Input
PO 480 - fan 1 (fans manually controlled)
PO 481 - fan 2
None of these point to the fault I'm getting, so on advice from a tuner 400 miles away (closest to me) he suggested disconnecting the Idle control valve connection to stop engine reving up when put in drive, and he also said that current idle speed is too low (as someone here pointed out), hence the PCM asking for more revs. I'll try this and report back.
Pete
PO 405 - egr signal low (removed by EFi live tune some time ago)
PO 449 - Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
PO452 - Evaporative Emission Control System Pressure Sensor Low Input
PO 480 - fan 1 (fans manually controlled)
PO 481 - fan 2
None of these point to the fault I'm getting, so on advice from a tuner 400 miles away (closest to me) he suggested disconnecting the Idle control valve connection to stop engine reving up when put in drive, and he also said that current idle speed is too low (as someone here pointed out), hence the PCM asking for more revs. I'll try this and report back.
Pete
Last edited by plastic orange; Oct 1, 2013 at 07:43 AM. Reason: Supplying more detail
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
Pulling the IAC connection only succeeded in increasing the idle speed to around 1000rpm (opposite to what I'd have thought) - code reader (snap on) didn't register that it was disconnected.
Have to clear space before putting it in gear to see if issue has stopped.
Pete
Have to clear space before putting it in gear to see if issue has stopped.
Pete
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
Well, it seems to be working as it should now - no real idea why though, but we played around with the idle control valve by disconnecting and reconnecting, plus took it for a scary drive to see if the gears changed.
It's going out again on Sunday for another drive to sort out brake balance - fingers crossed we're nearly there.
Shakedown vids - no heroics:
http://www.youtube.com/user/rmrresto?feature=watch
Pete
It's going out again on Sunday for another drive to sort out brake balance - fingers crossed we're nearly there.
Shakedown vids - no heroics:
http://www.youtube.com/user/rmrresto?feature=watch
Pete
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 59
Likes: 3
From: Broughty Ferry Scotland
I discovered that we'd set the aftermarket tacho to 8 cylinder when it should be 4, hence my quoted rev figures should be doubled. It's now idling at just under 1000 revs and all seems fine for now. No wonder it was overdriving the brakes.
I drove the car 100 miles home from the builder and it seemed to run pretty good. I never went over 2000 revs (72mph) as it was pissing with rain so was pretty cautious.
Pete
I drove the car 100 miles home from the builder and it seemed to run pretty good. I never went over 2000 revs (72mph) as it was pissing with rain so was pretty cautious.
Pete