Throttle body cleaning issues EPIC Volvo saga...RESOLVED!!

Post by **precopster** » 29 Jun 2013, 06:13

sergio wrote:Thank you Mike for the clarification.
I would have been lost in the wrong forest.

.

We would say "Up the creek without a paddle" here in Oz

draser · Post by **draser** » 29 Jun 2013, 08:48

Being as it may - the idea here is to find continuity between the 2. This is a "no power test - battery off" and there's nothing that can go wrong here. I'd start with placing one lead on the TB conn, then the other on the ECM conn (corresponding pin per diagram). I found that even with the "correct" schematics sometimes there are discrepancies. So if you don't see zero ohms on the meter I'd "search the ECM connector to cover all pins (generally in that same conn area of pins). The target here is to find some pin of ECM that has zero ohms with a pin of ETA. Another target is to find a pin of ETA that is the ground connection (so you check between ETA conn and chassis). The ground points for ETA and pedal are at shock towers, both sides.
And while you're in there I'd also test continuity between MAF conn and ECM - on the same page as ETA. One note for ECM - I see A pins, B pins, etc - so there may be several connectors (A, B) that you need to id before testing.

sergio · Post by **sergio** » 29 Jun 2013, 13:13

Ok, here is the result of continuity test

All pins show +- 1 ohm on the 200 ohm scale

I suppose to test the power on the pins I should put the ECM back on its shoe.

.

Post by **precopster** » 29 Jun 2013, 15:51

OK that result is good Sergio. Draser do you agree?

The MAF should be next followed by a voltage test at ETA connector with ignition on.

sergio · Post by **sergio** » 30 Jun 2013, 06:54

Thanks Mike, but good would be when someone says "Aha, so there WAS the problem"

!

Checked the MAF wiring as well. All +- 1 ohm
I followed Bosh made MAF on ME7 5 cylinder schematic

.

draser · Post by **draser** » 30 Jun 2013, 08:56

Good tests, the only thing that I was expecting different was to find a ground on one of the ECM pins. Haven't figured out how the throttle position feedback voltages are referenced w/out a ground. I believe the TB motor gets battery voltage and is controlled by a variable ground in ECM - so 2 wires should be for that. The twisted I believe are for feedback. The voltage test should match Vida readings, hopefully.

draser · Post by **draser** » 30 Jun 2013, 09:27

On page 5 attachement 1.pdf shows batt voltage 11.95V w/engine not running. That's not good. Batt needs to show some 12.6V w/engine stopped. If batt goes below 10V during cranking it may throw the modules out of whack. I'd check batt cables/posts for clean/tightness, check voltage again and if it's under 12V recharge. May be from all that cranking and not running.

sergio · Post by **sergio** » 30 Jun 2013, 10:38

.
The low voltage history;
I have had a battery drainage for some time. Sometimes overnight, sometimes after 48 hrs and sometimes even after a week the battery is too weak to crank. Since I couldn't find why, I resorted to disconnecting the battery when I got out of the car! The method never failed me. What I have realized since I'm having this oscillating idle (+- 800 - 1200 RPM) is that when the Key is in position II the battery goes down fast.
Yet I still have enough time to get the engine start and run.
All I want to do is to start and run the engine at a steady idle speed and see a response to the pedal. Then I could redo my checks and verification to find out the source of drainage. Which I was hoping to do before the summer!
The oscillating idle and non response to pedal came when I cleaned the PCV and the TB.
Right now I get cranks but it stalls after a minute of this oscillating idle.
I am sure I have done something wrong, a maneuver or a mistake when doing my PCV/TB job.
I would be surprised that this idle thing be the result of the low battery. But I will definitely address it right after the present one. (It was hard to work during the winter in a unheated shop or garage

)

.

Post by **precopster** » 30 Jun 2013, 16:01

precopster wrote: The MAF should be next followed by a voltage test at ETA connector with ignition on.

Have you ever done a voltage test at ETA connector?

sergio · Post by **sergio** » 30 Jun 2013, 17:25

.
I was about to ask if there is any other test that I should do before putting the ECM back on its shoe.
The reason being that the tool I made to remove/install it is a bit rough and I am afraid of braking the two sliding plastics that hold the ECM tight on base.

The voltage test is the next to do, tomorrow morning.
and thank you for your patience.

.

Throttle body cleaning issues EPIC Volvo saga...RESOLVED!!

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