Idle Surge

RoverLen said:

When my 95 RRC is in park everything is fine. Once i put in drive the idle will pulsate. Idel up - Idle down, Idle - Idle down. When it idles down it almost shuts off every time. I thought it was my IAC but would it "Pulsate" with the engine like clock work. i would think if it was the IAC it would do more of a random thing.


Thanks in Advance....



Len...

Click to expand...

Throttle Position Sensor

Is there any other tps sencer u can use or does it have to be factory?

From any other vel?

I have the same problem with the ldle, i was thinking but iac moter (stepper moter) but if it worked for u guys ill try it .

Check the TPS first by following the steps outlined in the repair book before condeming it. Otherwise you just change parts without finding the fault and this can become very costly......good luck

Does anyone know a cheaper alternative to the Genuine TPS that Rovers North wants ~300 for?

i have them used

I think DAP is the cheapest I've seen for new.
Either $175 or $65 depending on VIN because the type of connector is different.
http://www.dap-inc.com/parts/rrc/rrc_parts.shtml

I just went through this with my wifes 95 RRC.

The TPS was a bit out of range and the mixture voltage on the MAF had also creeped up.

by correcting these the idle went back to super stable and the mileage made a big jump back up getting 18MPG on our last 900 mile trip.

there is a great tech to learn how to adjust these things at the below link. I run both my MAFs 1.25 volts and the spark plugs have a perfect burn color at that voltage as aposed to the rich sooty burn they have at the factory 1.88 volts.

http://www.v8engines.com/

Musky we agree again, I am a 1.25 v man myself, much smoother idle, slightly better mpg as well.

:bigok: scott I would guess we are more alike then either would admit.

Shhh, don't tell anyone, we have our reputations to consider.

Muskyman- Could you provide more info on that tech article on the link. I couldn't find the article on the TPS or a search feature.

4x4stationwagon said:

Muskyman- Could you provide more info on that tech article on the link. I couldn't find the article on the TPS or a search feature.

Click to expand...

I believe Muskyman is referring to the following:-

http://www.v8engines.com/carbs-2.htm

scroll down to the section "Setting Air Mass/Flow Meter & Throttle Pot"

Find the Throttle pot on side of plenum. There are three (3) wires coming from this unit to a multi plug. Do not disconnect. Wire colors are Red, Green, Yellow. Red from volt meter to red wire of pot. Black wire from volt meter to Green of pot. Volts should read .33 to .35 volts if not, loosen the two (2) screws that hold it in position and turn it to get the correct voltage. If you cannot get the correct voltage setting, undo and remove the throttle pot, make the fixing holes elongated and you will be able to get the right voltage.

Please note that the following air flow meter settings should be made when the engine is warm.

The air flow meter wires can be accessed by pulling the rubber boot carefully backwards along the cable. Under here you will find the following wires. Red with Black trace = Sensor ground, Blue with Green trace = air flow signal, Brown with Orange trace = Ignition live 12 volts and Blue with Red trace = CO trim value. A digital multi meter should be used and connected to the sensor ground and CO trim value wires. The values that you are trying to achieve are below and these are adjusted by the screw on the side of the airflow meter.

Air Mass meter setting (non cat). The voltage reading on the CO value here should be between 1.0 and 1.5. If you have the Tornado ECU chip fitted then 1.5 volts should be aimed for.

Air Mass meter setting (cat). The best setting for the CO value here is 1.8 volts.

When setting your Throttle potentiometer and Air Mass/flow meter, you should also check the resistance scaling, using an Ohms meter and checking from highest to lowest resistance, smooth scaling is essential for the correct basic workings of all these units.

Are you both running without cats? Or if you do have cats, why did you go with 1.25V? Seems like a big difference from the recommended 1.8.

I am catless, I don't know about Musky.

the adjustment is a way to lean out or enrichen the mixture, I adjusted it and then after a few days checked the new plugs.

then did it again.

when the plugs looked perfect I noted the voltage as my baseline. I then did the same thing to my other truck and swapped in fresh plugs on it as well and guess what...those plugs looked perfect in a week of driving as well.

the factory setting on north american motors seems to be 1.88 volts and every one I have ever dealt with ran really rich and soots up plugs.

why waste fuel and burn it in the cats where it makes no power and dosent propel the truck down the road?

the combustion chamber dosent know if its carburated or injected, points or some crazy high energy ignition. all it knows is what the combined values produce in the burn.

use some old school mechanics and read your plugs and adjust the mixture based on what you see and your motor will run better and you will go farther on every tank of gas.

Thanks for the info, Muskyman, now I am looking forward to improve my milage from 14mpg.

Does the above also work on GEMS or just 14Cux?

Thanks Muskyman. The first time I checked/adjusted mine it was close to 3v!

Cux