Hi All

I’ve just bought a 2001 1.9D SX with 36k on the clock.

At 30mph (+- 2mph) in 4th gear only there is a flat spot in the engine when gently applying the accelerator to maintain a constant speed of around 30mph.

When accelerating up in gears below 4th and passing the 30mph mark before changing up, there is no problem. Even if engaging 5th at say 28mph (not normally recommended) the vehicle will accelerate without faultering.

It’s only this 30mph barrier in 4th gear that seems to be the problem. – Any ideas? would a diagnostic check show up the fault?

I think there was a software update to fix this on the 1.9D.

I've spoke to my local Techie at my local Fiat Dealers to day. He knows of no soft ware up date, and is suggesting an initial 1/2hrs check on the vehicle at a price of £40 and then go form there!

Sounds, rather costly.

It may be worth ringing up a few other garages asking if they know of the problem, that way they can pass on the information to your local one. Your local techie may not be too familiar with Doblo's if they don't get many in, especially many of the older 1.9D models.

Maybe oilrag may have more information about this?

I must admit to been a little surprised the 1.9d picks up speed at all when in
4th gear and only doing 30mph

MRT said:

I must admit to been a little surprised the 1.9d picks up speed at all when in
4th gear and only doing 30mph

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I was wondering about that. I don't change up to 4th untill I'm doing 40+ and 5th gear is 60+ I reckon. Sometimes I leave it in 3rd up to 50 mph. Cruising at 30 is deffo 3rd gear.

I have the JTD engine and I quite often use 5th (within reason of course) at 30mph on the flat around town or 4th if there are any small inclines etc. and I try never to go over 2000rpm before I change up a gear. Obviously if I use the motorway I use more of the gears then and keep the revs higher, this also helps to clear out the soot that's been building up whilst the revs are low.

Not only is the engine quieter but you save yourself some fuel too

But main diference been Ozzie yours is a JTD having driven a 1.9D I would never put it in 4th doing 30mph unless I was going down a ski jump at the time.

All well may be it is better not have a turbo, highly tuned, Doblo after all. As my simple tractor version (1.9D) pulls at low revs in all gears. Even below 30mph in 5th it is still able to respond to a gentle touch on the gas (oil) pedal. I can only imagine you JTD boys have to keep the engine revs high to encourage the turbo to provide any performance for you!

On the serious side of things, and back to my original query, I have now done some 500 miles since purchasing in my Doblo last Thursday, and for a tractor version pulls quite well. However, it’s still got this flat spot, right on 30mph in 4th. Which seems the right gear to be in on level ground, the engine seems to be revving higher than one would expect if left in 3rd. – Sorry I cannot give you a accurate rev counter reading as tractors do not have rev counters. I just rely on my forty-two years of driving experience to gauge the appropriate time to change up/down a gear.

I’m still interested in any constructive suggestions from anyone who may be able to help me conquer this annoying problem. In the mean time keep the banter following

I have 2001 tractor version, but there is no flat spot.

I have 05 1.3 doblo and thats got a bad flat spot, but I also have a 97 fiat Ducato 1.9 non turbo van which is generally OK with no flat spot, have you had it serviced, because when I service the Ducato van and change the air filter she picks up and drives much better.

Branchpipe said:

All well may be it is better not have a turbo, highly tuned, Doblo after all. As my simple tractor version (1.9D) pulls at low revs in all gears. Even below 30mph in 5th it is still able to respond to a gentle touch on the gas (oil) pedal. I can only imagine you JTD boys have to keep the engine revs high to encourage the turbo to provide any performance for you!

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Not really, I find that before the turbo kicks in at 1800-2000rpm there is still power to tap, and the revs do rise quite quickly... the turbo kicks and and you do feel it. As I said in my previous post I drive round town in 5th at 1000rpm, if I want to get out of the way quick I'll drop to 4th or even 3rd but for gentle acceleration any of the engines are fine

Ozzie1989 said:

I
1.9D models.

Maybe oilrag may have more information about this?

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It was the 1.9D in our 2002 Punto Ozzie. Like it from new and eventually Fiat came up with a fix. I thought from memory that it was a software update.

(I was told the hesitation at certain low speeds was something that was a problem with them all at the time.)

Regards

Ozzie1989 said:

I drive round town in 5th at 1000rpm,

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You're brave, it's way too easy to let you speed creep up, with the engine turning over so slowly, without realy noticing it. In a 30mph limit 3rd gear is fine, if your speed begins to build up the increase in engine speed is very noticeable and you soon slow down again - local rozers then have to look elsewhere to get their £60.

My problem seems to be an intermittent flat spot from a standing start.
It may be because I've only had the motor 2 weeks & prior to this I was driving a Honda Civic 1.4i auto so not yet used to the manual box?

Most times when I set off, dobbin will shoot away like a goodun but there is the odd time when it seems like there is nothing there & it takes a second or two, almost as if I'm trying to pull away in 2nd or 3rd!

These engines seem to differ alot. The non turbo sounds really troquey at low revs and the more power that Fiat squeeze out of it, the more revvy the engine gets. Has anyone driven the Grande Punto Diesel? Apparently it has the Dobbie engine but with 130bhp?!?

My 1.9 still is a bit reluctant until it is warmed up, then , it will cruise at 70+ with no problems.

Hi All, I’m back after a few weeks trying to sort out this flat spot problem, with no avail I hasten to add.

Firstly, I found the MAF had a split in its diaphragm and the connection arm to the butterfly flap had broken off. Ah, I thought this is the problem, but no, the car reacted exactly the same with a brand new MAF fitted as it did with the old one.

Secondly, I took the vehicle to my Fiat dealer for a computer health check. No errors were detected, the Techie at the dealers contacted Fiat Technical for further guidance, passing on to them some of the suggestion I gain here on the forum, a possible software upgraded being one of them. – Their reply was that this flat spot problem on the early 1.9Ds was a characteristic of the engine and not fix or flash upgrade to the software is available.

So it looks like I shall have to live with this annoying problem, unless of course any of you out there knows different?

RichDoblo120 said:

These engines seem to differ alot. The non turbo sounds really troquey at low revs and the more power that Fiat squeeze out of it, the more revvy the engine gets.

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The non turbo might sound torquey but be assured there is more torque in a twisted elastic band around a jam jar. Remember it has only 63bhp & reaches 0-60mph in 22 seconds.
If believe if they still made the engine available it would be the slowest car in the UK.

doblo said:

The non turbo might sound torquey but be assured there is more torque in a twisted elastic band around a jam jar. Remember it has only 63bhp & reaches 0-60mph in 22 seconds.
If believe if they still made the engine available it would be the slowest car in the UK.

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I thought the non-turbo produced about 95bhp
My old Pug Diesel had 80bhp with no turbo. It was 2.5l though.