apexblue

Hi, I am brand new to this forum today, as I bought my first Jeep in October. I had it remapped to 200BHP just before Xmas and it made a big difference to torque and mpg. However, last week I was driving down an A road at about 25mph and the power went completely and the engine cut out. I was able to pull over onto the path but could not get it started, neither could Green Flag.
It was towed to my local garage who tried to do a diagnostic on it but their equipment could not read anything, which I found very strange. My main mechanic who remapped it and did a diagnostic last month could not find any issues at that time. He is going to re-do it tomorrow, but has anyone had this problem before, if not any ideas please?

The local garage is suspecting a faulty fuel pump, but he does not want to replace it without a diagnostic first, which may point to that being faulty?
Thanks
Steve

dave1123

I have absolutely no idea what vehicle you're talking about. Please enlighten me. Are you in the UK?

apexblue

yes im in the UK and the vehicle is in the heading. a 53 Plate Grand Cherekee CRD Auto.

dave1123

Are you talking 1953 or a code 53? Are we talking diesel or what? I'm not familiar with that code "53 Plate CRD.

dave1123

Are you talking 1953 or a code 53? Are we talking diesel or what? I'm not familiar with that code "53 Plate CRD".

apexblue

Its a 2003 Chrysler Jeep Grand Cherekee CRD Diesel Automatic. 2.7 Merc unit, which has been remapped to 200bhp. It was on a 53 number plate not an 03 plate, if that make sense?

dave1123

Now we're talking! If you're not getting fuel pressure, it may be the pump or it may be electrical or the filter. I'm not really familiar with jeep's diesel fuel systems, but It shouldn't be too hard to figure out. Not having an ignition system makes it easier.

Having said that, it being a Merc engine leaves me clueless. If you have fuel pressure, you still might not have injector signals. On US petrol jeeps, there is a crankshaft position sensor that usually is the cause of sudden engine failure. Without this signal, the PCM or "brain" shuts off fuel and ignition. I'm not aware if you have one, but it gives you something to look for.

I think for a starting point, you should check fuel pressure. Then jumper the pump to see if it gets you pressure. Then see if you have injector power while cranking. Then it gets interesting. It could be a sensor or (worst case) PCM failure. The security system may be involved. The electronics are a little above my knowledge, but I'll help all I can.

If nobody has said this before, welcome to CF!

jtodaro

What's a 53 number plate?

apexblue

A 53 plate means my vehicle was made and registered in the UK in the year 2003. Have you had any experience with my problems outklined above?

dave1123

BTW apexblue, I have a little knowledge of the UK having been to Portsmouth for replenishment while in the Navy and spending 1 week in London. I've been a student of British history during WWII and the Blitz. I also watch "Top Gear" when it's on BBC America. As Winston Churchill said "We are one people separated by a common language", but it gets complicated at best. This is a joke, but do they tax the air you breathe?

Most of my diesel knowledge was learned on the big lorries, but without electronics. For instance, the original 250 Cummins diesel used mechanical injectors driven by a camshaft.

Merc has always been the finest in diesel technology, but I've never worked on one. The most common problem with any diesel is fuel delivery.

sycoglitch

How did you have it remapped. Did you do it yourself. Did you change anything afterwards or kept stock parts. Trying to recall my CRD knowledge but drawing a blank. What happens when you turn the key

apexblue

I had the remap done by a specialist about 2 months ago which took the bhp to approx 200 and the torque was also much improved. I dont think this has anything to do with the vehicle breaking down, as i have done about 600 miles since it was remapped.
When i turn the ignition key the engine turns over but it just will not start. My local garage could not get their diagnostic machine to open the engine module, so basically could not read anything. They have recommended an ECU specialist, so im getting a transporter to take it there on Wed and will let you all know the outcome.
Steve

sycoglitch

Im trying to recall the diesel engine and i can't picture it. Sucks when you're away from on for too long. What have they verified so far

apexblue

Its the merc diesel 2.7 litre. I wont k ow the diagnosis until later this week