Potentiometer swap out for KE-Jetronic

[jane_doe2023]

I express my gratitude for your timely response provided in the past, as it has shown to be beneficial to me even after a span of 8 years. In the case of my 1991 300E equipped with the M103 engine, there is occasional variability in the startup process, wherein the vehicle may either commence immediately upon ignition in the morning or need a somewhat extended period for the cranking process. Furthermore, it has been observed that the idle speed gradually increases to 900 revolutions per minute (rpm) during the car's warm-up period, then stabilising around 600 rpm. Although this behaviour may first seem within an acceptable range, it is worth noting that several sources suggest an expected idling speed of 1200 rpm. An further peculiar symptom seen was the abrupt movement of the vehicle upon shifting into the "Drive" gear. It is uncertain if this is relevant, but all other aspects seem to be in order. After doing a comprehensive inspection, I have examined the majority of components and have recently replaced all of the fuses, which were found to be the original ones installed in the vehicle. This factor significantly impacted the vehicle's drivability, as it resulted in a perceived increase in power output and smoother shifting. Subsequently, an assessment of the resistance at the air flow potentiometer was conducted, yielding outcomes that align precisely with the aforementioned description. Initially, the resistance exhibited typical behaviour, but upon applying pressure to the plate, it transitioned into an open circuit state before subsequently returning to its original state. Notably, the recorded numerical values exhibited a slow increase followed by a subsequent decline. Nevertheless, it was observed that upon descent, the resistance would stabilise at a distinct value during periods of inactivity. In general, it seemed to be characterised by inconsistency.
I intend to first choose for an aftermarket component in order to identify the issue. If this proves effective in resolving the problem, I will thereafter transition to using Bosch components exclusively. I will also provide updates.

[Hannah_Baker2000]

It is OK to go to that location, provided that all hardware and software components of the information technology system are current. At what point in time were the plug leads, distributor top, and rotor replaced?

[jane_doe2023]

Two years ago in January 2021, it is reasonable to exclude such options for the time being.

[Hannah_Baker2000]

The engine's revolutions per minute (rpm) of your vehicle, as well as the M103 engine, are both 900rpm.Subsequently, my score decreases to about 750. Potentiometer faults manifest as intermittent fluctuations in the rotational speed, whereby the revolutions per minute (RPM) seem to be present momentarily, followed by a sudden absence of movement, and thereafter resuming without delay. Have you performed internal cleaning of the -IAC valve? It is essential to promptly repair any hoses that have split.

[jane_doe2023]

It is indeed reassuring if your experience aligns with mine. I used brake cleaner to cleanse the intake valve control (ICV). Furthermore, it should be noted that there is a hose split present on both ends. However, it was seen that the split was able to create a somewhat tight seal, despite its condition. I have captured photographs and am now in the process of uploading them.

Using a potentiometer, I conducted measurements of resistance between pin 1 and pin 2. When the plate is deflected, there are certain places at which the resistance increases to a very large value, approaching infinity, before subsequently returning to its original state. It is hypothesised that there may exist areas with little or no signal coverage.

Additionally, I own a little smoke machine. I am interested in knowing the precise location at which smoke should be introduced in order to effectively assess all vacuum lines, including the idle control valve (ICV). Is the brake booster vacuum line enough, or should I consider introducing smoke via the air intake?

[Hannah_Baker2000]

The use of a smoke test is recommended for assessing the functionality of the brake booster.It is anticipated that a greater number of faulty hoses will be identified via the use of smoke testing. It is important to rectify any identified vacuum leaks in order to ensure optimal engine performance. Please provide the current value shown on the economic gauge located on the dashboard.

[jane_doe2023]

The cluster in my vehicle lacks an economy gauge.
However, an intriguing development has occurred: today, after a period of two days, I initiated the ignition of the vehicle and it promptly began operation despite being in a state of complete coldness. The user's text lacks academic formality.
There has been no manipulation or adjustment of the object in question over the last 48 hours, with the exception of minor modifications made to the belt. It is worth noting that these efforts were unsuccessful, as the 19mm bolt exhibited significant resistance and did not yield to manipulation.
I am now experiencing a state of uncertainty on the distinction between moral correctness and error.

The next test aims to determine if there are any leaks in the idle air control pipes by conducting a smoke test.

[Hannah_Baker2000]

Could you please confirm whether you own a handbook for the M103? Is the bolt responsible for retaining the tensioner or the adjustment bolt? Specifically, is it bolt 16 or bolt 5?