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Old 14th December 2019, 17:30   #1
Alan_M
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Default Advice on whether my injectors have had it

I’ve only had this car a very short time and the list of jobs done and needing to do seems to be getting longer every time I look at it.

Today’s problem to sort.

The idle is quite lumpy, it can be a little smoky at idle and when revved - black/blue, low on power and seems to have a little miss.

I’ve downloaded a diagnostic program and looked at the injector values and I believe 3 of them are outside normal values. One of them doesn’t even fluctuate.

The values at idle are (mm^3)
Cyl 1 +10.00 and no fluctuation
Cyl 2 -0.43
Cyl 3 -3.04
Cyl 4 -9.99

RPM values
Cyl 1 748
Cyl 2 804
Cyl 3 770
Cyl 4 792

At 2000 rpm
Cyl 1 +10.00
Cyl 2 -1.57
Cyl 3 -3.23
Cyl 4 -7.08

RPM
CYL 1 2008
CYL 2 2032
CYL 3 2018
CYL 4 2024

These are all with the MAF disconnected as this is also duff.

So am I looking at needing to replace number 1 and 4 and possibly number 3 as well?

Is it worth running some neat injector cleaner through them?
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Old 14th December 2019, 21:38   #2
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Make sure the ECM isn't swimming, and any tuning box, if fitted, is removed.

I've never seen injector balancing figures as poor as that with the car still able to actually run

Injector 4 is probably OK, start with injector 1, as number 4 compensation figures are in the minus to accommodate the failings of number 1

Brian

Last edited by marinabrian; 14th December 2019 at 21:41..
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Old 14th December 2019, 22:36   #3
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Quote:
Originally Posted by marinabrian View Post
Make sure the ECM isn't swimming, and any tuning box, if fitted, is removed.

I've never seen injector balancing figures as poor as that with the car still able to actually run

Injector 4 is probably OK, start with injector 1, as number 4 compensation figures are in the minus to accommodate the failings of number 1

Brian
Does having the MAF disconnected have anything to do with the poor readings?

As it reverts to a de-fault setting?
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Old 15th December 2019, 01:53   #4
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Quote:
Originally Posted by marinabrian View Post
Make sure the ECM isn't swimming, and any tuning box, if fitted, is removed.

I've never seen injector balancing figures as poor as that with the car still able to actually run

Injector 4 is probably OK, start with injector 1, as number 4 compensation figures are in the minus to accommodate the failings of number 1

Brian
Thanks.

Inspecting and rodding the plenum is on my to do list. I will elevate that to the top of the list and try to have a look tomorrow.

I don’t think this car has had much love by its previous owner. Found the MAF disconnected, EGR badly gummed up, the rear window being held on by the washer jet and the wiper bolt - scared to keep looking
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Old 27th December 2019, 00:19   #5
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Finally found some time between work, family and the rain to do a little more diagnostic testing of the injectorrs.

Carried out a leak off test with following results

Cranking only without starting for 30 seconds

Cyl 1 4ml
Cyl 2 3ml
Cyl 3 1.7ml
Cyl 4 6ml


At idle for 2 minutes

Cyl 1 35ml
Cyl 2 25ml
Cyl 3 25ml
Cyl 4 35ml

So it seems all 4 are outside the recommended parameters and need to be replaced.

Any thoughts welcome.
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Old 27th December 2019, 08:38   #6
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Originally Posted by Alan_M View Post
Finally found some time between work, family and the rain to do a little more diagnostic testing of the injectorrs.

Any thoughts welcome.
Try some injector cleaner, before getting too involved.

Empty out the diesel filter, refill with cleaner, start the engine and run for a few seconds - long enough to get the neat cleaner into the injectors, then leave the car overnight. Drive it as normal next morning.
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Old 27th December 2019, 15:59   #7
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+1 to Harry.

Soaking the injectors overnight in neat solution works quite well.

Although I would take it for a somewhat more spirited 2 -3 mile jaunt....
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Old 28th December 2019, 13:01   #8
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Quote:
Originally Posted by HarryM1BYT View Post
Try some injector cleaner, before getting too involved.

Empty out the diesel filter, refill with cleaner, start the engine and run for a few seconds - long enough to get the neat cleaner into the injectors, then leave the car overnight. Drive it as normal next morning.
totally agree with this.

These are TOAF injector readings the morning after I serviced the car. Filled a new fuel filter with Forte Diesel Treatment (eBay LINK), after being recommended to try it on this site. Fill the fuel filter with it, start car, and run for 20-30 seconds. Switch off and leave to soak overnight. The next day, I took it for a bit of a run, and a little italian tune up (as much as an auto will let you lol). After, the car felt a little smoother, and a little more eager. I dont know how much of what I felt was a placebo, but the figures do show a little benefit to doing it.

I now change my fuel filter and use the Forte every service. The difference I feel now is not noticeable, but then that has to be expected if the Forte works. I did try the same method with Redex Fuel treatment neat in the filter - just to see if it would do the same job for less, but there was no difference in the numbers, unfortunately.
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Old 28th December 2019, 15:26   #9
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I put some injector cleaner through them. Not Forte, but some liqui moly which I could lay my hands on. This gave some improvement to 2 of the injectors, but the other two were still really bad and engine still really rough at idle, missing at higher revs and a loud knock when pulling away.
I’d already got hold of a full set of used injectors a couple of weeks ago which had been tested via T4 and known to be good. So decided to delve in and replace them. I’ve only done this once before a couple of years ago on a Merc. That was a pig of a job as it was suffering from Black Death. So was very pleasantly surprised how easy it was in this car - all done in a couple of hours.
I’ve not had chance to check the leak off of these injectors, but compensation figures are all below 1 and engine vibration, smoke on startup gone knocking gone plus the engine has a more power and pulls much better.
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