1.2 8v rough at idle, starting up with a delay

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1.2 8v rough at idle, starting up with a delay

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Hello guys,


I have a 1.2 8v Doblo that is a bit rough at idle and it is difficult to start (it always start, but it seem to be doing too many revolutions before actually start: as a reference, I can count 1001,1002,1003).

Air filter, spark plugs, HT leads and battery changed; no improvement.


In the next days, I will change the muffler and an exhaust pipe.

I did a quick copression test, engine warm, only dry test.

cyl 1: 11 bar
cyl 2: 10 bar
cyl 3; 9.9 bar
cyl 4: 9.9 bar

seems pretty consistent, perhaps a bit lower than I expected ....
the insulation of the HT lead on cyl 1 was a bit damaged...

I've checked the ECU using MES, but at a first glance nothing seems out of the ordinary. I've tried the self adjusting procedure (three times a 4500 rpm for 3 seconds) and nothing change.

Tomorrow all try the auto learning procedure for the phonic wheel.
At high revs, the engine seems ok, without loss of power.


Any suggestion of what to check first?

Replace the coil where the slightly bad ht leads was attached?

Check for poor timing belt fitting?


Thanks
 
Hello guys,


I have a 1.2 8v Doblo that is a bit rough at idle and it is difficult to start (it always starts)

Check for poor timing belt fitting?


Thanks


Hi.

The 8v FIRE are primitive..

Will run acceptably if a couple of teeth out (not 7 teeth..I tried..)

Is the fuel pump priming ok?


Ok..engine health.

Is it oil and water tight?

If its losing coolant.. it COULD be head gasket

If its oil and watertight..

It will NOT be a headgasket issue causing poor running.

I personally cannot see an exhaust system issue either.. BUT :

Lambda sensors.. worth checking


What build year is this Doblo ?

Charlie
 
Thank you guys for your replies!!

we bought the Doblo, new, in 2001; and it is practically new even now (it hasn't reach 70k km), always driving around for very short distances.

There are some problems regarding maintenance; has been used by some of my relatives, but only now I can look at it thoroughly.

Before changing the muffler I was having problem with cold starts and, with engine warmed up, when releasing the gas pedal from medium high revving.

After the replacing, the second problem seems disappeared: perhaps because the muffler was full of debris and too much water.


As you suggested it can be a little leak from the head gasket; the problem is that the reserve tank was almost empty (leak? bad maintenance?), with Paraflu11 coolant, that I don't use anymore. So I flushed the system and change to g12+ coolant, and I am waiting for the level to stabilize or to reveal a leak.

The fuel pump
is priming ok; with warm up engine and high rev, the engine is strong (...65hp strong ;-...).
I've tried to do a fuel pressure check, but I discovered that my fuel kit doesn't have the right Schrader adapter....
Anyone knows where to find the right adapter?


@varesecrazy
hot-restarting is all right;
Problem is when the engine is cold; I've noticed a slightly better start in dry cold mornings vs. rainy mornings, but that was before I changed the ht leads (one was split open). It has never rained again till now.

Today I discovered that the spark plugs I bought are not right (even if the website where I bought them stated the were suitable for a doblo 1.2 8v) ;They are iridium spark plugs; I've check for the combustion residue, and they are too white; then I check on the ngk cross reference for normal/iridium plugs, and they are the wrong iridium type.
 
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hello guys,

still waiting for spark plugs... but now I know I have big fish to fry.
I've noticed that the reservoir level drop more than expected (too big to be an airlock being pushed out)
So I tested with chemical the vapors from the reservoir tamk, and the response was positive (dark blue to light yellow).

I think the culprit is the headgasket near cylinder 1 (the one with the higher pressure during the pressure test: I was doing a "wet test" because of the coolant leakage.).


The problem is probably due to corrosion: coolant was never changed: 18 years instead of 2!


Do you think is worth to change the HG on a Doblo 2001 1.2 8v with 70k km on the clock?

I never changed one but I think I have all the right tools (except for timing tools).

Is there on fiatforum some guide/post on this matter that I absolutely have to read ???
 
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