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Hi all,

 

Wondered if you could help with this one, I'd usually ring up Jeff and book her in up in Birmingham but this one is leaving me reluctant to drive the ~125mi up there.

 

Idle is rough, really rough. Car is rocking a bit kinda rough. It gets progressively worse up until about 3,000 RPM then it's a little better but the exhaust note is not how it usually is. It doesn't seem to boost to more than about the 0PSI mark so I'm assuming I'm in safety boost also?

 

It sorta sounds a bit like a tractor so I'm again assuming I'm down a cylinder. I suspect it could be an injector but I'm not positive. I'm mechanically inclined but not mechanically knowledgeable about 300s despite owning mine for about a year now.

 

It's a 1991 twin turbo, UK and manual if that makes any difference.

 

All 6 injectors were replaced up with Jeff last September with used parts and everything has been fine until now. I've also read about det sensors possibly being an issue? I don't have access to any ODB scanners so I couldn't tell you if I'm getting any fault codes.

 

Any help/advice would be great!

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  • Author

Hi all,

 

Wondered if you could help with this one, I'd usually ring up Jeff and book her in up in Birmingham but this one is leaving me reluctant to drive the ~125mi up there.

 

Idle is rough, really rough. Car is rocking a bit kinda rough. It gets progressively worse up until about 3,000 RPM then it's a little better but the exhaust note is not how it usually is. It doesn't seem to boost to more than about the 0PSI mark so I'm assuming I'm in safety boost also?

 

It sorta sounds a bit like a tractor so I'm again assuming I'm down a cylinder. I suspect it could be an injector but I'm not positive. I'm mechanically inclined but not mechanically knowledgeable about 300s despite owning mine for about a year now.

 

It's a 1991 twin turbo, UK and manual if that makes any difference.

 

All 6 injectors were replaced up with Jeff last September with used parts and everything has been fine until now. I've also read about det sensors possibly being an issue? I don't have access to any ODB scanners so I couldn't tell you if I'm getting any fault codes.

 

Any help/advice would be great!

I'm guessing that you may be down more than one cylinder. First stop would be the injector and coil pack connectors I reckon.

I'm guessing that you may be down more than one cylinder. First stop would be the injector and coil pack connectors I reckon.

agreed....

 

you could try unplugging everything you can find, "one at a time" and check the connectors, clean if dirty / corroded.

 

make sure you do the MAS as well ( in the nose cone), easy to get to only two bolts hold the panel on...

 

check each coil pack by disconnecting them to see it find what cylinder isn't working (if that is the problem).

 

you could also try running it with the MAS unplugged to see if its any different.

 

start with that and see what you find.

 

where abouts in Wales are you?

agreed....

 

you could try unplugging everything you can find, "one at a time" and check the connectors, clean if dirty / corroded.

 

make sure you do the MAS as well ( in the nose cone), easy to get to only two bolts hold the panel on...

 

check each coil pack by disconnecting them to see it find what cylinder isn't working (if that is the problem).

 

you could also try running it with the MAS unplugged to see if its any different.

 

start with that and see what you find.

 

where abouts in Wales are you?

  • Author

So disconnect the batt and try just pushing each connector in to make sure there's nothing loose?

  • Author

So disconnect the batt and try just pushing each connector in to make sure there's nothing loose?

You can get the fault codes from the ECU itself with just a screwdriver.

 

Try unplugging the wire to the coil pack, and if it runs differently, it's working - if it's the same, then it's the coil pack/spark plug. A lot of these things are just trial and error, but try getting the fault codes first >> http://www.ttzd.com/tech/diagnostictech.html

You can get the fault codes from the ECU itself with just a screwdriver.

 

Try unplugging the wire to the coil pack, and if it runs differently, it's working - if it's the same, then it's the coil pack/spark plug. A lot of these things are just trial and error, but try getting the fault codes first >> http://www.ttzd.com/tech/diagnostictech.html

  • Author
You can get the fault codes from the ECU itself with just a screwdriver.

 

Try unplugging the wire to the coil pack, and if it runs differently, it's working - if it's the same, then it's the coil pack/spark plug. A lot of these things are just trial and error, but try getting the fault codes first >> http://www.ttzd.com/tech/diagnostictech.html

 

Cheers for that, great little tip. I'll keep it bookmarked.

 

Unfortunately I'm getting 55 which seems that, by their reckoning at least, there are no errors.

  • Author
You can get the fault codes from the ECU itself with just a screwdriver.

 

Try unplugging the wire to the coil pack, and if it runs differently, it's working - if it's the same, then it's the coil pack/spark plug. A lot of these things are just trial and error, but try getting the fault codes first >> http://www.ttzd.com/tech/diagnostictech.html

 

Cheers for that, great little tip. I'll keep it bookmarked.

 

Unfortunately I'm getting 55 which seems that, by their reckoning at least, there are no errors.

I won't be back in Cardiff until next week but could bring up my conzult and put in on your car then...

 

also if you find one cylinder that doesn't seem to be working, pull out the coil and plug and check for spark on the plug.

 

by the way the two at the back are a ping because you have to remove the balance bar.

 

there are measurements you can do on both the coil pack and injectors (in the Service manual) to check them.

  • Author
I won't be back in Cardiff until next week but could bring up my conzult and put in on your car then...

 

also if you find one cylinder that doesn't seem to be working, pull out the coil and plug and check for spark on the plug.

 

by the way the two at the back are a ping because you have to remove the balance bar.

 

there are measurements you can do on both the coil pack and injectors (in the Service manual) to check them.

 

Okay nice one thanks, if there's a gap in the rain today I'll try the suggestion above about unplugging and plugging things back in.

 

I'm not exactly stranded by it as I use a motorbike most of the time and I work from home it's just a bit frustrating more than anything else!

 

Thanks for everyones hep so far, definitely a step in the right direction I think! :yes:

So disconnect the batt and try just pushing each connector in to make sure there's nothing loose?
Have engine running.
  • Author

All sorted now guys.

 

I'm not sure what 'number' injector was at fault but it was the front left connector that seemed to be loose, popped back in and she's running better than she has for months. I assume it's been making its way out for a while based on how good it felt to drive earlier.

 

Many many thanks !

glad to here it's sorted...there is an upgrade to a different connector on the injectors that gives a more reliable contact, problem suffered on models up to 92', i believe, i'm sure its covered on the forum.

Edited by SteveE

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