Low Idle update

[Aren Jay]

I had my Marauder in the shop today. Private shop. They checked the IAC and the MAF and the airflow filtre stuff etc... Nothing wasn't working. There was a little carbon build up that they removed but that wasn't the problem.

They also checked to make sure the electrical system was up to spec and that was fine too.

My idle RPM is still low.

In park or neutral it sits at 600 625, in gear 500ish.

So what else could it be?

They suggest a complete fluid cleaning, anything else I should be looking at?

[MitchB]

From the factory, your car will idle in neutral at 640 RPM. In gear idle speed is 544 RPM. Your tach probably has some error. Are you sure something is wrong?

Mitch

[Aren Jay]

They checked with Ford who said it should Idle between 790 and 815 rpm. Which seems to be what everyone else has. Ask around.

It stalls on me at lights.

[Marauder386]

From the factory, your car will idle in neutral at 640 RPM. In gear idle speed is 544 RPM. Your tach probably has some error. Are you sure something is wrong?

Mitch


Is that correct Mitch ? I always thought it was 750 and 550 ... which is close on the "in Drive" anyway ...


:cool:

[MitchB]

They checked with Ford who said it should Idle between 790 and 815 rpm. Which seems to be what everyone else has. Ask around.

It stalls on me at lights.

790-815 is what is published in the Ford powertrain control/emissions diagnosis service manual - which is what was referenced by whomever you spoke with. However, the values I gave come directly from the powertrain control calibrations. There are modifiers that can change the actual idle speed you will see, but 640/544 pretty much agrees with what I saw on my stock 03 MM.

Mitch

[Marauder386]

790-815 is what is published in the Ford powertrain control/emissions diagnosis service manual - which is what was referenced by whomever you spoke with. However, the values I gave come directly from the powertrain control calibrations. There are modifiers that can change the actual idle speed you will see, but 640/544 pretty much agrees with what I saw on my stock 03 MM.

Mitch


I dont think I can go that low with my XCal2 and D R tune ....


:cool:

[Aren Jay]

Did it change for 04's?

if the in gear is 544 or 550 what would cause mine to drop to less than 500 (400-450 range) Even dips way below that when I turn the wheel left. Down to 200 - 250 range, this is how I stalled, I was sitting at a light turning left and a road that is a left turn.

With the low Idle my engine is almost silent, with the radio on low I didn't even realize I stalled, until the light turned green.

[MitchB]

Did it change for 04's?

if the in gear is 544 or 550 what would cause mine to drop to less than 500 (400-450 range) Even dips way below that when I turn the wheel left. Down to 200 - 250 range, this is how I stalled, I was sitting at a light turning left and a road that is a left turn.

With the low Idle my engine is almost silent, with the radio on low I didn't even realize I stalled, until the light turned green.

You have a pressure transducer in the power steering pressure line between the pump and the rack. Based on the transducer output - which reads pump output pressure, there is a calibration table that adds in air to the engine to offset the load imposed by the pump. Your individual car might need this calibration increased - provided your pump pressure is not excessively high or discounting any other problems.

Mitch

[Pat]

That is good to know about the transducer. I often wondered why my engine speeded up a little whenever I turned the wheel from a stop.
Prolly does it when it's moving but one can't tell.

Thanks for the post.

[Aren Jay]

thanks something to look into.

[jonroe]

They checked with Ford who said it should Idle between 790 and 815 rpm. Which seems to be what everyone else has. Ask around.

It stalls on me at lights.

That's not what I have. The OBDII port shows idle about 600 or even in the upper 500s when warm and in drive. When you hook up a laptop with SCT LiveLink you can also read the "demanded idle" which is the idle speed requested by the computer and it pretty well matches. I have no driveability issues with about a 600 rpm idle.

[Aren Jay]

I'm booked in for a Motor vac, whatever that is, and they will check the Power steering transducer and do a complete spark plug check. On Monday.

Anything else I should suggest they check?

[Raudermaster]

In drive, with my Lidio tune, I'm at about 650. Just right.

[Blackened300a]

They ever check the voltage of the TPS??
My 03 Avalanche had a voltage issue with the MAF. It would be normal for a little while then it would drop voltage and make the idle drop to about 400 RPM's.
The dealer had a hard time finding it.

[Aren Jay]

They did mention something about checking the voltage, I'll add that to the list. though. Anything else I should check?

[hot-rauder]

Did it change for 04's?

if the in gear is 544 or 550 what would cause mine to drop to less than 500 (400-450 range) Even dips way below that when I turn the wheel left. Down to 200 - 250 range, this is how I stalled, I was sitting at a light turning left and a road that is a left turn.

With the low Idle my engine is almost silent, with the radio on low I didn't even realize I stalled, until the light turned green.

same thing has happened to me... then it stopped after an oil change... my brother said it was weird but then when he had his oil changed on his MM it was lower too... just above the lowest tick on the tach... dont know exact speed sorry. dealers say it is normal and the car doesnt drive any worse, just when you give it a little to impress thekids it bogs down breifly afterwards and seems to almost stall.

[Aren Jay]

I had a Motorvac Fuel injection cleaning done.
- Air intake cleaning
- Fuel injection cleaning

Had the Spark plugs inspected. (good)
Had the Power Steering Transducer Checked (no fault found)

They did find a TSB for the Variable Assist power steering Module containing symptoms for Low Battery voltage & RPM Surging and Stalling.

They recommend Re-Programming the PCM.

What do you think?

[MitchB]

I had a Motorvac Fuel injection cleaning done.
- Air intake cleaning
- Fuel injection cleaning

Had the Spark plugs inspected. (good)
Had the Power Steering Transducer Checked (no fault found)

They did find a TSB for the Variable Assist power steering Module containing symptoms for Low Battery voltage & RPM Surging and Stalling.

They recommend Re-Programming the PCM.

What do you think?

What is this going to cost? I don't know if this will solve your specific problem. You could reprogram the car yourself with a Lido or Reinhart tune.... I would think either would work with you to get things just right if you were to have any problems.

Mitch

[sailsmen]

Could it be a bad battery?

[rvaldez1]

I had a Motorvac Fuel injection cleaning done.
- Air intake cleaning
- Fuel injection cleaning

Had the Spark plugs inspected. (good)
Had the Power Steering Transducer Checked (no fault found)

They did find a TSB for the Variable Assist power steering Module containing symptoms for Low Battery voltage & RPM Surging and Stalling.

They recommend Re-Programming the PCM.

What do you think?

Does anyone have the TSB on this? I have had a similar problem on the CV. They have replaced the tensioner, idler pullies and the alternator. Problem persists.

[Aren Jay]

What is this going to cost? I don't know if this will solve your specific problem. You could reprogram the car yourself with a Lido or Reinhart tune.... I would think either would work with you to get things just right if you were to have any problems.

Mitch

Cost for a re-programme is $450.00

What does a Reinhart or Lido tune cost?

Should I step up to 4.10 rear end and get an appropriate 4.10 tune? (or should I get everything working properly first?)


Could it be a bad battery?

I'll ask them if they tested the battery.

I think they did, but it can't hurt to ask.

[MitchB]

Cost for a re-programme is $450.00

What does a Reinhart or Lido tune cost?

Should I step up to 4.10 rear end and get an appropriate 4.10 tune? (or should I get everything working properly first?)

I'll ask them if they tested the battery.

I think they did, but it can't hurt to ask.

If it were me, I would reprogram the car with a performance tune. Not sure on cost, but should be about the same or even less. Gears are your choice.

Mitch