[neilb1798]

i have a 1996 slk 230 auto i bought it with the problem im having cheap enough so hopefully someone can shed some light so far i have:
changed the cps
changed the k40 relay
checked fuel
all is good the car turns on the key it fires up then stops before idling when this happens the car shuts the spark off
when i got the car it has the 3 pin plug down on the drivers foot well looks like an immobilizer key hole ive traced the wires and they go into the alarm the problem came about when then battery went flat on the car a year ago and had the problem since.
any ideas i have browsed the forum and the have seen similar problems but not the same.
the car unlocks and tries to start on the key

 

[neilb1798]

any ideas really at a lose end with this

 

[neilb1798]

done abit more i have power to the coils 12v perm and no ground from the ecu that why im not getting a spark has any body come across this thanks

 

[JiminFL]

i have a 1996 slk 230 auto i bought it with the problem im having cheap enough so hopefully someone can shed some light so far i have:
changed the cps
changed the k40 relay
checked fuel
all is good the car turns on the key it fires up then stops before idling when this happens the car shuts the spark off
when i got the car it has the 3 pin plug down on the drivers foot well looks like an immobilizer key hole ive traced the wires and they go into the alarm the problem came about when then battery went flat on the car a year ago and had the problem since.
any ideas i have browsed the forum and the have seen similar problems but not the same.
the car unlocks and tries to start on the key

Are you telling us that the car hasn't run for a year?

If the alarm system is aftermarket, I would get it out of the picture and then continue troubleshooting. It sounds like something an alarm would do. Just to tease the thief

 

[neilb1798]

the hasnt run for a year and the alarm that is in is a Mercedes one the one that looked after market ie it still all plugged to the main one via splitters i took out but this did not cure the problem so put back in.
the alarm all works as it should put the battery on the alarm goes off bonnet open press button alarm stops and it does turn over which the alarm stops
thanks for reply

 

[Veloman]

i have a 1996 slk 230 auto i bought it with the problem im having cheap enough so hopefully someone can shed some light so far i have:
changed the cps
changed the k40 relay
checked fuel
all is good the car turns on the key it fires up then stops before idling when this happens the car shuts the spark off
when i got the car it has the 3 pin plug down on the drivers foot well looks like an immobilizer key hole ive traced the wires and they go into the alarm the problem came about when then battery went flat on the car a year ago and had the problem since.
any ideas i have browsed the forum and the have seen similar problems but not the same.
the car unlocks and tries to start on the key

I had the same problem occur a few years ago. It turned out to be the fuel pump. Make sure you have your fuel pressure checked. It may be something as simple as a fuel filter plugged up or the crankshaft position sensor not working correctly. In any case it sounds like you have checked the ignition system thoroughly. Do the same with the fuel system.

 

[neilb1798]

I had the same problem occur a few years ago. It turned out to be the fuel pump. Make sure you have your fuel pressure checked. It may be something as simple as a fuel filter plugged up or the crankshaft position sensor not working correctly. In any case it sounds like you have checked the ignition system thoroughly. Do the same with the fuel system.

ive checked the filter so you would suggest tring the pressure whats the pressure at the rail supposed to be i have crimped the return off already that did not have an effect on the car and crank position has been checked and replaced thanks for reply i will som how get a gauge attached in at the moment its on the hold as i im just changing an engine in another car

 

[Veloman]

ive checked the filter so you would suggest tring the pressure whats the pressure at the rail supposed to be i have crimped the return off already that did not have an effect on the car and crank position has been checked and replaced thanks for reply i will som how get a gauge attached in at the moment its on the hold as i im just changing an engine in another car

I believe 54-61 psi at the fuel rail is correct. The pressure regulator is in the fuel filter and I have read that these are sometimes faulty depending on manufacturer. When the car is first started the fuel pump is signaled to run for a few seconds to get the pressure up on the fuel rail. Then with the engine started, the crank position sensor keeps the fuel pump on. I had my independent mechanic check my car when it wouldn't start and had a faulty fuel pump. This occurred when the car was hot.
Your car may have a different regulator set-up as mine is a 2004 model.

 

[neilb1798]

sorry for the late update just to let you all know i ended up buying another ecu and key and transponder is there a way of coding these up i thought they would be plug in and play with all the things i had the car turns over only three times if i to ignition fast other wise it doesnt do anything
any ideas
Many thanks
Neil

 

[Subby_]

with the ECU coding or rather introducing it to the rest of the system can be done with carsoft or STAR DAS (dealer).

if the old ecu is still talking the software copies the settings and then asks you to replace the ecu. once in it writes the old ecus coding to the new. if the old ecu is not talking then it can be manually coded only by dealer.

with the key and transponder this is a dealer job as it links into the immobilizer. ecu failing and keys failing are rare...

if the immobilizer has failed the car wouldn't start at all and START ERROR would come up on the dash. the key is being authenticated as it is starting...

 

[neilb1798]

the car does turn over on the orignal ecu and key but does not start has compression and fuel and spark so can only put it down to the ecu doesnt come up with any codes but does read it.
the new one does not turn at all so this would need to be coded to the car is it a dealer only that can do this or can it be done else were as they like to charge 125 plus vat a hour
thanks for reply
Neil

 

[neilb1798]

right did abit more on the car today and found out with the orignal ecu the spark only works when i turn the key straight to start if i put into pistion 2 first it doesnt spark

im losing all hope for this now ready just to strip it and scrap the ecu still isnt bringing any codes up i know it has fuel and spark can be achevied by flicking the key straight on but its find the cause as im losing the will to live
thanks for advise
Neil

 

[neilb1798]

Right i have now got the car into the garage as its been a while since i can work on it i have took the hydrolic lifters out as they had gone solid gave it a new oil filter and oil
checked the fuel pressure and its at 55psi
the car only starts if it is left for a good week and then it runs on two the compression on all cylinders is at 180 psi on all bores also

what else could this be im really struggling now like you wouldnt believe i may just scrap the car its had new coils new plugs new leads