Back to running rich and stalling again. Only cold tho.
#1
Back to running rich and stalling again. Only cold tho.
Ok,
so my car is back to running rich and stalling again on cold only.
once car is warm it idles and runs well.
not running rich at all when warm
So it is definitely changing between hot and cold mode.
really not sure what it could be.
the idle speed is ok when cold.
it is blowing black smoke and smells really rich.
and will stall on acceleration at times.
can’t think what this could be that only causes issues when cold.
so my car is back to running rich and stalling again on cold only.
once car is warm it idles and runs well.
not running rich at all when warm
So it is definitely changing between hot and cold mode.
really not sure what it could be.
the idle speed is ok when cold.
it is blowing black smoke and smells really rich.
and will stall on acceleration at times.
can’t think what this could be that only causes issues when cold.
#3
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#7
The MAF as a Lucas AM 20 ( or something like that ) was used on the Land Rover model P38 ( ? )
at the proper idle speed you should see on yours 1.2 volts DC on the middle wire ( Green / Pink ) at the connector ( pin stab method ), this would prove the MAF is alive
The MAF is powered as B + voltage and has a splice and same large ECU controlled relay # right 5
Warm at the idle speed and faulting would not be related to injectors unless they warm up also ( ? )
Power " sitting " on the injectors check and how , current limited ? , there is a large ECU controlled relay # right 5 as the source and some splices
In reality the mega splice can not fit so is broke down into 3 or 4 splices to fit loom space
Print is more clear with a double click
at the proper idle speed you should see on yours 1.2 volts DC on the middle wire ( Green / Pink ) at the connector ( pin stab method ), this would prove the MAF is alive
The MAF is powered as B + voltage and has a splice and same large ECU controlled relay # right 5
Warm at the idle speed and faulting would not be related to injectors unless they warm up also ( ? )
Power " sitting " on the injectors check and how , current limited ? , there is a large ECU controlled relay # right 5 as the source and some splices
In reality the mega splice can not fit so is broke down into 3 or 4 splices to fit loom space
Print is more clear with a double click
Last edited by Parker 7; 10-02-2024 at 10:43 PM.
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#8
The MAF as a Lucas AM 20 ( or something like that ) was used on the Land Rover model P38 ( ? )
at the proper idle speed you should see on yours 1.2 volts DC on the middle wire ( Green / Pink ) at the connector ( pin stab method ), this would prove the MAF is alive
The MAF is powered as B + voltage and has a splice and same large ECU controlled relay # right 5
at the proper idle speed you should see on yours 1.2 volts DC on the middle wire ( Green / Pink ) at the connector ( pin stab method ), this would prove the MAF is alive
The MAF is powered as B + voltage and has a splice and same large ECU controlled relay # right 5
#9
#10
To read the MAF with hand meter it has to stay connected as a return to ECU signal , it needs to be powered by one of the other wires the 3rd being a car frame ground
The engine valve cover is not a good ground , it is electrically isolated by plastic shouldered bushings
Probably the best one is the small ground terminal on the rear engine firewall
Someone used the large B + on the firewall by mistake ( easy ) and flashed his meter
The engine valve cover is not a good ground , it is electrically isolated by plastic shouldered bushings
Probably the best one is the small ground terminal on the rear engine firewall
Someone used the large B + on the firewall by mistake ( easy ) and flashed his meter
Last edited by Parker 7; 10-02-2024 at 11:27 PM.
#11
i replaced that temp sensor a little while ago.
back at the beginning of 22.
it does appear to read accurately based on what my torque app shows.
it appears it operates fine as car is good once warmed
#12
So we are looking at open loop mode
Question is how is that regulated ( O2 sensors are not used for fuel trim )
Question as the throttle butterfly is at the idle stop ( minus throttle butterfly stop screw inside the TB ) My X300 did not seem to have one when I took mine apart
So when the ECU sees the TPS voltage value as a trigger to command certain things to " fixed " values , injector pulse width , IAC valve to arrive at the on paper idle speed
or the ECU changes things to arrive at the paper idle speed , obviously not
In the back ground you have vacuum leaks , Evap system fails including Rochester valve back by the tank , smog pump that has 2 check valves
The smog pump will run for 60 ( ? ) seconds only triggered by ?
injector cleaner ? EGR valve clean ?
The EGR has a position sensor to read position error as target 0 % PID = EGR_Error with ELM - 327 device , there is a common meter value on X wire per wiring guide values sheet on the page before the actual wiring picture / schematic
Someone " recovered " their idle with a EGR cleaning and another with Rochester valve replacement ( watch proper Rochester tubing positions as that was found )
One EVAP system tube was totally missing on mine , from under the intake manifold fitting
And one last mystery item seldom talked about is the brake booster and that wierd fitting at the intake manifold , this leak should be overcome in effect by the engine suppling more vacuum on throttle up
My Mom says I have to go to bed , dialysis in the morning
Question is how is that regulated ( O2 sensors are not used for fuel trim )
Question as the throttle butterfly is at the idle stop ( minus throttle butterfly stop screw inside the TB ) My X300 did not seem to have one when I took mine apart
So when the ECU sees the TPS voltage value as a trigger to command certain things to " fixed " values , injector pulse width , IAC valve to arrive at the on paper idle speed
or the ECU changes things to arrive at the paper idle speed , obviously not
In the back ground you have vacuum leaks , Evap system fails including Rochester valve back by the tank , smog pump that has 2 check valves
The smog pump will run for 60 ( ? ) seconds only triggered by ?
injector cleaner ? EGR valve clean ?
The EGR has a position sensor to read position error as target 0 % PID = EGR_Error with ELM - 327 device , there is a common meter value on X wire per wiring guide values sheet on the page before the actual wiring picture / schematic
Someone " recovered " their idle with a EGR cleaning and another with Rochester valve replacement ( watch proper Rochester tubing positions as that was found )
One EVAP system tube was totally missing on mine , from under the intake manifold fitting
And one last mystery item seldom talked about is the brake booster and that wierd fitting at the intake manifold , this leak should be overcome in effect by the engine suppling more vacuum on throttle up
My Mom says I have to go to bed , dialysis in the morning
Last edited by Parker 7; 10-03-2024 at 12:12 AM.
#14
No egr here.
could be air leaks.
i have no way to test.
need a smoke machine.
idle speed is good so i don’t think it is iacv.
o2 sensors only used once warm is good to know.
can rule those out. I replaced them not long ago so assumed it is not them
could be air leaks.
i have no way to test.
need a smoke machine.
idle speed is good so i don’t think it is iacv.
o2 sensors only used once warm is good to know.
can rule those out. I replaced them not long ago so assumed it is not them
Last edited by Spud Maat; 10-03-2024 at 12:38 AM.
#15
Running rich would be a clue of a vac leak and not exhaust manifold leak into biasing the O2 sensors ( not being used ) to run rich fuel trims
Short term fuel trim #s until it shifts
I'm not clicking at this time the relationship between vac leak and running rich
Again as you throttle up the vac supply amount overcomes a leak so would see a change in stumble ( ? )
Short term fuel trim #s until it shifts
I'm not clicking at this time the relationship between vac leak and running rich
Again as you throttle up the vac supply amount overcomes a leak so would see a change in stumble ( ? )
Last edited by Parker 7; 10-03-2024 at 12:59 AM.
#16
#17
Unplugging the MAF will run in a less then optimum engine regulation using a different set of maps minus the MAF and making assumptions and not having timing advance under load that it can't determine minus the MAF to TPS expected correlation ( spread ) as a load determination
Last edited by Parker 7; 10-03-2024 at 02:38 AM.
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