I have a 2000 E430 that does not accelerate immediately when I step on the gas pedal.A couple of seconds later it will then "take off". It is "studdering" at times (like a miss or backfire), but drives smooth at high speeds. Also, the cruise control went out at the same time, it willonly work under about 40mph but will not set at speeds over that. When I try to set the cruise control, I feel the cruise controlabout to setbut then it goes off. Any advise or do I just need to take to the dealer?

 

Initial reaction = Throttle actuator being to fail.

However......

Get DTC codes read and come back.

Make / Model / Service History?

Stuart

 

The first time I scanned, codes were as follows:PO306, PO305, PO303, PO720, PO306, PO308, PO300, PO500 pd, and PO303.

When I ran the codes a second time, they changed slightly, PO306, PO305, PO303, PO308, PO302, PO304, PO300. These are the most recent, however now the vehicle will not evn accelerate.

 

Simple.

You have misfire on 2,3,5,6,8 and also intermittent on all cylinders. Strange 1 and 4 are giving less of a problem.
You also have a speed sensor problem...P0500/0720 impacts the cruise control and potentially throttle response (EA electronic accelerator)

Issue is what is the cause. Looks like more than one problem at the same time but this is very unusual.

Service history?

1. Misfire.
One question please. Does this problem appear to be engine temp sensitive.
Either way the Crank position sensor. (Low cost and easy to replace) COULD be the cause.
However I would eliminate Fuel system problems andO2 sensors before changing anything.

Need to look at voltage coming off O2 sensors.
Need to check fuel rail pressure.

If you have a misfire on all cylinders the cause must be common to all cylinders.

Crank sensor doesn't set a code other than you don't get a spark at the correct point = misfire. Known problem component but usually give temp sensitive warning (won't restart when hot) before giving up completely so doesn't fit exactly to your symptoms...unless you didn't tell us about this characteristic.

Low fuel rail pressure will likely be the fuel filter relief valve.

O2 sensors getting old if voltage low.

2. Lack of Cruise. Speed signal is shared with ABS/EPS/ASR/Speedo etc. Strange this should go at the same time.

Is there anything you haven't told us? have you had new tyres / brakes fitted? Could be one of the wheel sensor wires has been damaged etc.
Have you reset (erased) the codes? If so do they reappear etc and if so what do you get.

it appears you have two different issues although the possiblity of a linkage between them exists. However I can't think what such a link would be when stationary.

Good luck. Stuart

 

I am having NO temperature issues.

However, there was a recent change in tires and size.
I put on the front245/ 40 /17, rear tires 245 /45 /17.
Original size was 235/ 45/ 17.

No other activity on vehicle.

 

Oh, and I have not reset the codes at all. Should I?

 

incorrect tyre size will shut the cruise down thats 100%,with luck of power sounds or accleration sounds like MAFF SENSOR DEFECTIVE IF THE MAFF SENSOR IS DEFECTIVE IT ALWAYS GIVES THE 02 SENSOR FAULT,BEST THING TO DO IS TO PUT ON DIAGNOSTIC AND SEE IF 02 FUNCTION ON ACTUAL VALUES 100% FUNCTION WILL BE OK ITS SOUNDS AIR MASS FAULTY..........

 

Incorrect tyre size CAN upset Cruise especially different front to rear (or side to side!!) since the ECU has an algorithm to check the relative tyre speeds which must fall within a given range of one another and a set standard. Strange ABS etc are OK so I'm not sure that it is "100% the tyres". I asked the question for a reason. If the two events happened together then you have your answer. If not I'm not convinced. Are you sure your ABS/ASR is OK? I assume you understand how these systems are supposed to work??

MAF fault does not always give an O2 sensor code! Usual "code signature" is P0170/P0173. However MAF is high on the list of possible faults since it is ONE of the main inputs to the fuelling ECU but expensive to swap out if not the cause. MAF out of range is very common at say 3 to 4 years / 60k+ miles.

Unless you clear the codes the CEL will remain on. If the CEL comes back on with the same codes you can be sure you have a problem as indicated by the codes EVEN if you think the car is working fine.

My original reply remains valid.
Some elimination is required before spending lots of money on swapping out components. if you can get a more sophisticated diagnostic scanner that can read live data I should like to know what the LTFT and O2 values are. The ECU also stores the conditions present at the time the CEL was switched on. i.e. Ambient, throttle position, engine temp etc etc.

No temperature effects lowers the likelyhood of the Crank position Sensor BUT does not remove it as a possibility.

So I'd still start with damaged injector wiring insulation (visual inspection), ensuring fuel pressure rail pressure is correct, then go for the CPS because it is inexpensive and easy to change, then the MAF which is more expensive (unless you just try cleaning with solvents but this is not always effective) although easy to fit.

I don't like spending ANY money unless absolutely necessary so endeavour to understand the problem before swapping bits out and if I do swap a part out and find it is not the cause I put the old bit back again and keep the new part for another occasion.

Something I have not suggested is an air leak after the MAF and before the engine valves. Has somebody recently taken the MAF off. Did the problem occur after the car had been to garage etc? If so need to ensure that a leak is not present. i.e. is one of the gaskets incorrectly fitted or missing? Usual test is to squirt a little petrol (PRECAUTIONS REQUIRED DUE TO FLAMMABILITY!!) around the air inlet joints. If revs rise you have a leak.

Stuart

 

Can someone please tell me where the crank position sensor is located on the 2000 e430.