Stumbling engine - Troubles again :(

[bzguy]

Haven't driven my car since about 10 days, took it for a long run today, but got the following problem :

All ok, driving fine, all of a sudden (unpredictable) following problem :

- no power anymore, engine stumbling, RPM don't go up when accelerating, car's "shocking"

- on idle, RPM's needle goes mad (wildly up and down), engine stays low on RPM, engine even stops (idle RPM suddenly too low)

- light "check engine" flashing, or remaining on

- when "check engine" light goes on while driving, boost = max 0.5 bar (emergency program I suppose)

- turning off engine, waiting a bit "solves" the problem

- all other temp and other readings fine

Never had this before, but have it since my BOV came loose (went open quite soon, @ about 0.5 bar).

Adjusted BOV (set spring more tense, don't know when it opens now, but NOT soon) , have less problem since, but problem persists.

What should I do ?

- remove BOV to see if problem persists without BOV ?

- check chip ? (chip is installed since 2 months, never had any problem)

- check other things ?

Remarkably : when engine runs fine, boost goes > 1.2 bar when accelarting hard ! Normal behaviour ?

Any ideas more than welcome !

Sorry, unable to use freescan

Edited February 27, 2007 by bzguy

[ErnieHillard]

I cant believe no one has replied to this post. First thing to check would be the MAP sensor and look for vacuum leaks. But you say if you turn it off it runs fine for a bit and starts messing up. So in thinking a MAP works or it doesn't so rule that out(i know it should be heat sensitive). The 02 in not sure if it would run fine get hot and read wrong? Freescan is a really big help with that kind of stuff.

I would remove the BOV, and reset the ECU. Let it idle for a few min. then drive it 20 to 30 miles and see if it fixes itself. If not check the spark plugs and see what the look like. That will tell you if it is getting to little fuel(lean) or to much fuel(rich) .

I have just bought a new MAP, 02 sensor, two new coils, and a fuel psi regulator and, some other stuff trying to get a similar problem on my 93 SE/s4, idles great and runes fine for 10 to 15 min of driving

when the motor will start missing and fussing goes into safe mode of .5 bar max , and if i clutch it rev the motor above 5000rpm a few times it will go back to high boost mode. but it will rev out in only on gear ma by 2 before going back in to safe mode. Every time i try this it comes back to the shop with fuel fouled spark plugs. so a new set plugs go back in (usually AC#4's)

I ordered a new in box ac ECU today should be in Tuesday!! eager to try it out!!!

Ernie Hillard

Edited December 17, 2006 by ErnieHillard

[Jonathan]

Prob is freescan will tell you within about 2 seconds whats wrong and with the sensor display it will tell you what the sensors are doing even if they are working but slightly out of their perameters - it's a total god send.

You say it wont work - why not, if it's laptop issues seriously consider re-investing in a laptop or a convertor to get the computer talking to the car, if it's car issues whats the prob and mebbe we can solve it.

[Paula&Marcus]

Hi,

sounds like a bad TPS sensor or a bad MAP-sensor. Of course could also be the wiring respective the pressure line that goes to the MAP-sensor.

Please, check the sensors and the wiring and the pressure lines !

Cheers

Marcus

Haven't driven my car since about 10 days, took it for a long run today, but got the following problem :

All ok, driving fine, all of a sudden (unpredictable) following problem :

- no power anymore, engine stumbling, RPM don't go up when accelerating, car's "shocking"

- on idle, RPM's needle goes mad (wildly up and down), engine stays low on RPM, engine even stops (idle RPM suddenly too low)

- light "check engine" flashing, or remaining on

- when "check engine" light goes on while driving, boost = max 0.5 bar (emergency program I suppose)

- turning off engine, waiting a bit "solves" the problem

- all other temp and other readings fine

Never had this before, but have it since my BOV came loose (went open quite soon, @ about 0.5 bar).

Adjusted BOV (set spring more tense, don't know when it opens now, but NOT soon) , have less problem since, but problem persists.

What should I do ?

- remove BOV to see if problem persists without BOV ?

- check chip ? (chip is installed since 2 months, never had any problem)

- check other things ?

Remarkably : when engine runs fine, boost goes > 1.2 bar when accelarting hard ! Normal behaviour ?

Any ideas more than welcome !

Sorry, unable to use freescan

[bzguy]

Hi,

sounds like a bad TPS sensor or a bad MAP-sensor. Of course could also be the wiring respective the pressure line that goes to the MAP-sensor.

Please, check the sensors and the wiring and the pressure lines !

Cheers

Marcus

- I'll check (probably tomorrow) the lines, see if something's not perfectly tight (don't know where the MAP sensor is located, but I'll sure find it I guess)

- I do have freescan package (from Marcus), a brand new laptop, but no RS232 port ; maybe I can borrow a laptop from a friend of mine, or look for a descent convertor

- I'll disconnect the ECU, reconnect and do a ride

- good news is : just installed my new AWI's, pics to follow ...

thx all, I'll keep you updated !

[bzguy]

This eving, checked almost anything I could check, but nothing loose to see :s

Disconnected/reconnected the 4 connectors on the ECM-box, reset the fuel pump, checked all other connections, nothing odd to remark ...

Took it for a 40 km drive, all ok, but after 20 km same problem : "check engine" light on, stumbling engine ...

Tomorrow I'll remove the BOV, see if that helps, I do have an aldl cable (don't know where to connect though), I'll call a friend of mine who has a laptop with RS232 port on it ...

I can also put the original chip back (now it's a #3 chip, from Marcus), if it doesn't help it won't harm I guess ...

Really strange : no problems since months ... :s

What I was thinking about : the MAP-sensor : is it something that simply does work or doesn't work ? Or can there be 'intermediate' behavious ?

[Jonathan]

Have you got a USB port ? (most likely yes)

Get in touch with Kato, buy the LEW convertor lead, plug and play - job done.

You wont regret it, worth its weight in gold.

[bzguy]

Have you got a USB port ? (most likely yes)

Get in touch with Kato, buy the LEW convertor lead, plug and play - job done.

You wont regret it, worth its weight in gold.

I'll do, thanks !

Still have to find out where to connect the aldl connectors, I'll check the Esprit Service Manual...

I suppose freescan is pretty straight forward ?

Forgot to mention this : when parking the car for a while when not driving, I always disconnect the battery by using a 'Bosch Key' ; should I quit doing that, as I always reset the ECU this way ?

Last to mention is : stumbling ALWAYS begins after a while, let's say 20 km's, NEVER directly !

Edited December 17, 2006 by bzguy

[Vulcan Grey]

I'll do, thanks !

Still have to find out where to connect the aldl connectors, I'll check the Esprit Service Manual...

I suppose freescan is pretty straight forward ?

Forgot to mention this : when parking the car for a while when not driving, I always disconnect the battery by using a 'Bosch Key' ; should I quit doing that, as I always reset the ECU this way ?

Last to mention is : stumbling ALWAYS begins after a while, let's say 20 km's, NEVER directly !

Disconnecting the battery with your cutoff switch will cause the ECU to go into a fairly long relearing process, and it will drive poorly for a while. If you have a battery drain, you might try locating and fixing that rather than applying a bandaid to cover up the problem.

[bzguy]

Disconnecting the battery with your cutoff switch will cause the ECU to go into a fairly long relearing process, and it will drive poorly for a while. If you have a battery drain, you might try locating and fixing that rather than applying a bandaid to cover up the problem.

Stupid thing is : there's no drain @ all, just do it to prevent stealing my car

Did this from day 1

So in fact : I'll have to relearn my ECU again and then NOT disconnect the battery anymore ? So maybe it's quite normal then, the stumbling, as a part of the learning process then ? Strange that it only occurs now, since I'm driving the car for months already, and always disconnecting the battery zith the cut-off switch :s

Edited December 18, 2006 by bzguy

[ErnieHillard]

[

My 93 has been doing something really close to what yours is doing. I get in it cold let it warm up a min or 3 drive off. It seems to run fine until it gets up to 70 to 80 deg. C then it starts breaking up stumbling i put my foot down it will only build .5 bar of boost. Check engine light come on sometimes but not every time. When i hook freescan to it and drive every thing looks fine then the 02 sensor starts reading rich and it stumbles and breaks up. When the check engine light comes on freescan locks up until the light goes off. Free scan starts back up i hit the trouble code button and it said no reported faults. Every time this happens I stop and pull the spark plugs and they are jet black. I an interested in what your plugs look like.

I have changed MAP, fuel psi regulator, coils, spark plug wires, temp sensor that the ecu reads, and the 02 sensor. Next Ill be changing the ECU when it arrives tuesday or wednesday.

Ernie

[bzguy]

[

My 93 has been doing something really close to what yours is doing. I get in it cold let it warm up a min or 3 drive off. It seems to run fine until it gets up to 70 to 80 deg. C then it starts breaking up stumbling i put my foot down it will only build .5 bar of boost. Check engine light come on sometimes but not every time. When i hook freescan to it and drive every thing looks fine then the 02 sensor starts reading rich and it stumbles and breaks up. When the check engine light comes on freescan locks up until the light goes off. Free scan starts back up i hit the trouble code button and it said no reported faults. Every time this happens I stop and pull the spark plugs and they are jet black. I an interested in what your plugs look like.

I have changed MAP, fuel psi regulator, coils, spark plug wires, temp sensor that the ecu reads, and the 02 sensor. Next Ill be changing the ECU when it arrives tuesday or wednesday.

Ernie

Sounds like the same problem !

I'll remove temporarely my BOV, I'll put back the original chip, and I'll have a look on my spark plugs, what they look like ... But what if O2 sensor reads rich ? What to be done then to get it less rich ?

[bzguy]

Sounds like the same problem !

I'll remove temporarely my BOV, I'll put back the original chip, and I'll have a look on my spark plugs, what they look like ... But what if O2 sensor reads rich ? What to be done then to get it less rich ?

Managed to get a RS-232 to USB convertor (good pc team we've got overhere) ; I'll try to test this afternoon ...

[mwmackenzie]

I had a Grand Cherokee that did the same and it was a faulty O2 sensor.. the sensor was telling the ECU tht the car was running rich so cut back the fuel.. started stumbling abd stalling and only did it when the car was hot.. cot a good 15 mins out of it til iy started happening....

Mark

[bzguy]

I had a Grand Cherokee that did the same and it was a faulty O2 sensor.. the sensor was telling the ECU tht the car was running rich so cut back the fuel.. started stumbling abd stalling and only did it when the car was hot.. cot a good 15 mins out of it til iy started happening....

Mark

sounds exactly the same problem ; I'll check on the O2 sensor ... any idea how much an O2 sensor costs ? And available @ my local car parts shop or should I have to order elsewhere ?

Curious about freescan, will try this afternoon, if I get freescan running off course, lol (aldl connector is underneath the passenger's footwell I guess ) I can check on that in my service manual ... (not right now, now @ work)

[bzguy]

quick check with freescan : all 0's (unrecognised header)

I suppose got the right aldl connector ? The one behind the glovebox, hanging loose ?

Using the aldl under the glovebox, using approved USB - RS232 adaptor ; using NO gender changers (9p female directly connected to usb adaptor)

I'll have a try on the aldl connector in the back ...

Edited December 18, 2006 by bzguy

[Loteuk]

quick check with freescan : all 0's (unrecognised header)

I suppose got the right aldl connector ? The one behind the glovebox, hanging loose ?

Using the aldl under the glovebox, using approved USB - RS232 adaptor ; using NO gender changers (9p female directly connected to usb adaptor)

I'll have a try on the aldl connector in the back ...

Had a similar problem that manifested since the Factory visit - the actuator on the waste gate was very stiff causing no power and no boost.(easy fixed)

It became intermittent and then showed the characteristics you discribe but without the engine light on (perhaps that is because of the frequent resets)

I assume that this would not register as a fault with Freescan??

[Dermot]

Tony,

You can monitor the action of the wastegate and actuator by looking at the Wastegate Duty Cycle in the Freescan log.

A lit Check engine light means a Cat A code which will be stored in the ECU, I would read that in Freescan. A log file will also track it down.

Unrecognised Header is typically a communications error. I bet you have an incompatible Serial-USB connector. The one available on LEW works and comes with technical support from me. Many do not work.

http://www.esprit4sale.co.uk/Sale/pages/Diagnostics.html

Dermot

[bzguy]

Tony,

You can monitor the action of the wastegate and actuator by looking at the Wastegate Duty Cycle in the Freescan log.

A lit Check engine light means a Cat A code which will be stored in the ECU, I would read that in Freescan. A log file will also track it down.

Unrecognised Header is typically a communications error. I bet you have an incompatible Serial-USB connector. The one available on LEW works and comes with technical support from me. Many do not work.

http://www.esprit4sale.co.uk/Sale/pages/Diagnostics.html

Dermot

Hi Dermot,

do you accept international bank transfer (IBAN/BIC) ?

Please PM me for further details, I'll buy a good one, it's driving me crazy not finding what the problem is !

[Jonathan]

I ploughed through loads of USB-COM port convertors and the only one to work was the one Dermot / LEW sorted out, plus the pennies go towards the HUGE work Dermot / LEW do for Esprit owners in general and freescan.

Dermots write ups (available on LEW) are a complete must have.

You might have a gender issue (hahah sorry had to put that one in ) with your cables though, again when I did mine some gender changers swap the send/recieve and some dont so I made my own with easily interchangable wires to get the right config.

One you have it set you'll wonder how you survived without it - I periodically check my cars to monitor the ECU - as I say you can see things going wrong before they render the car 'off road' often at large expense.

The kit is a gem and even most of the the dealers don't know about it !

On the battery thing, do you use a security type device ?

You can get these things that have a key which effectivly takes out the cable but leaves a fused 5A wire in place to keep the alarm / ECU happy. This is fine, ideally what you shouldn't really do is disconnect the battery completely.

[bzguy]

I ploughed through loads of USB-COM port convertors and the only one to work was the one Dermot / LEW sorted out, plus the pennies go towards the HUGE work Dermot / LEW do for Esprit owners in general and freescan.

Dermots write ups (available on LEW) are a complete must have.

You might have a gender issue (hahah sorry had to put that one in ) with your cables though, again when I did mine some gender changers swap the send/recieve and some dont so I made my own with easily interchangable wires to get the right config.

One you have it set you'll wonder how you survived without it - I periodically check my cars to monitor the ECU - as I say you can see things going wrong before they render the car 'off road' often at large expense.

The kit is a gem and even most of the the dealers don't know about it !

On the battery thing, do you use a security type device ?

You can get these things that have a key which effectivly takes out the cable but leaves a fused 5A wire in place to keep the alarm / ECU happy. This is fine, ideally what you shouldn't really do is disconnect the battery completely.

LOL, Jonathan, be sure : no gender issues (in any way ) ...

Yesterday, removed the BOV (problems started after BOV was set too loose, opening way too early) ; test drove it : same problem : stumbling starts after a while, when everything's well warmed up ...

I'll order a USB convertor (asked Dermot to PM me), maybe I can check on my spark plugs too ; I don't know if it might be a good idea to put the original chip back ?

Edited December 19, 2006 by bzguy

[bzguy]

Still haven 't got the time to check it further out, will order a cable from Sanji, but here some pics, as promised ; new wheels installed (but car dirty )

[lrg_machine]

I've been having similar engine stumble lately.

The cars had a new turbo, exhaust manifold, cat bypass and new through silencer, service amounting to a C service with all belts, fluids, plugs leads etc.

Car was fine for a while then started missfiring stumbling and zero power under load. No engine check lights though

I took the car to Sportomotive and they changed the coil pack, and it's a different car, more responsive, smoother drive.

Maybe you have the same problem, only trouble is, the coil packs aint cheap.

Check all the connections to the coil pack as well, mine were very corroded.

Just a thought.

[Jonathan]

Is that FOUR pipes ?

Any pictures of the system ?

Very cice car btw !

[bzguy]

Is that FOUR pipes ?

Any pictures of the system ?

Very cice car btw !

Thx !

Yes, 4 pipes :

Changed the number plate holder to V8 style, but no pics of that yet ...

Edited December 22, 2006 by bzguy