Technical 1994 1.4 i.e Tipo Idle problem ( Help!! )

[punto-paul]

Hi Everyone!! I've bought a M reg 1.4 Tipo i.e off this very forum a few months ago to use for my daily commute to work.


However when it's running at full temperature it'll idle normally one minute, then all of sudden run at a faster idle of it's own accord?

It does go away back to a normal idle, but I really have to rev it to make it go away which I don't want to do so I've stopped driving it.

I changed the stepper motor for a brand new Bosch item, which did make the car run more smoothly than it did before.

But the problem still occurs? I'm thinking it could be the Digiplex as that has a vacuum pipe and a plug going to it.

Unfortunately money is tight, and I can't afford to pay a garage and don't want to start buying loads of bits that it doesn't need.

Any idea's if the Digiplex is a common fault, or should I be looking elsewhere?

Your comments or advice would be much appreciated


Cheers,

Paul

 

[dave]

i'd check for air leaks thats cheap, spray carb cleaner around inlet manifold and throttle body area when engine is running, if engine speed changes you have found a leak

 

[SFB]

Vacuum leaks are easy to find, just listen for extra loud hissing noises.

As "money is tight," was the "stepper motor" changed for any specific reason?

Digiplex wouldn't cause that symptom.

The Tipo is a beautifully simple piece of engineering by today's standards, worth ten modern electronic junk heaps.

 

[punto-paul]

Definitely a whole lot easier to fix the Tipo yourself, compared to it's more modern rival's so I think I've made a good choice

I tried the stepper motor for 2 reason's really... the first being when my mum had an Uno 1.4 years ago it was the cause of a multitude of running / idle problems so I thought it would be the source of my woes. But obviously not!!

The second being the part was new & free!! plus it was a genuine Bosch Item like the original. So I knew I was replacing it with something that was like for like quality, rather than chancing a second hand one or some dodgy copy!!

But cheers for the tips, I'll look at the vacuum pipes and check for air leaks hopefully I will find the cause


Wish me luck!

 

[SFB]

One other point to check, the "gasket" under the carburettor is a solid rubber block that doesn't last forever, it splits and lets air in.
It's easy to check, simply rock the carb in all directions and listen for a change in engine revs.

I'm thinking that as the idle rate changes of its own accord, an air leak isn't likely to be the cause of this problem, but with luck, it is.

 

[dazzo666]

hiya, after owning lots of teapots over the years try and disconnect the wts these play up on the 1.4, the digiplex system is pretty bullet proof so thats no problem , in the original owners manual there is a procedure to reset the idle control valve, cannot remember if this is for the 1.4 or 1.6. the 1.4 i had the same problem like i said but in the end i just put a 1.6 complete unit on there.

 

[SFB]

It's a bit early in the AM for me, dazzo666, but I can't think what the wts could be.

Is it similar to a sao, or a wtf?

 

[punto-paul]

Cheers for the advice it's much appreciated I'm going to have a look tomorrow morning as the car is at my dad's house. And remove the shed load of leaves that it's now covered in!!

So I'll check the SPi / carb unit and try and move it see if that changes the engine revs at all, and have a scan through the original Fiat owners manual see if there is a reset procedure for the idle control valve

Hopefully I'm not sounding like a idiot when I ask this, but dazzo666 what is a wts ?

There is a Tempra 1.6 breaking on eBay at the minute which isn't too far away, so if I think there 's anything looking suspect I can hopefully get some parts from it if the piggy bank allows it.

Wish me luck...

 

[SFB]

Paul, do you have a Haynes?
If not, is there a particular section you'd like posted?

I've worked with carburettors since the 60s and a 1.4 Tipo since 99, but I've never heard of an idle control valve and it isn't mentioned in Haynes either.

There's nothing in the owner's manual, apart from how to adjust the idle screw on page 100 in mine, in Spanish.

 

[punto-paul]

I've got a Haynes, but it only covers the pre facelift car not my later model so I'm not sure that it'll be suitable

But there is definitely no EGR valve on my car, I'm suspecting the engine management temperature sensor could be the cause.

But as I haven't had chance today to check the other things, I can't rule them out just yet either

So I need to get on it this week, as I'd like to get the car back out on the road so I can lay my Uno up over winter

 

[bluejohn125]

Hi Paul

Dazzo's WTS must be Water Temp Sensor, on the back of the inlet manifold with a 2-pin connector. They can give problems and need replacing, quite cheap and easy-ish to do (need a good 19mm spanner to remove it). As there are only a few sensor inputs to the old, simple system this could be worth checking, I'm debugging a persistent misfire on my 95 1.4ie at the moment and that sensor (and its dodgy wiring) were giving problems.

You could change the coolant completely and refill and bleed properly (not too easy on a 1.4..) just to be sure there are no airlocks to give confused signals.

I think it will come down to systematic, sensible elimination of possible problems because the trade will not know these systems any more so it's pot luck whether you find someone with experience somewhere or follow your own logic (like you're doing).

I don't suspect it's the digiplex itself, just something like a sensor, wire or dodgy hose confusing the unit.

Good luck..

 

[punto-paul]

Cheers bluejohn125 think I need it, I was planning to have a look the weekend just gone.

But with family visiting I just didn't get time anyway hopefully back to the Tipo this weekend!!

I thought the wts could be referring to the 'water temperature sensor' but wasn't 100% so least that's confirmed that we're both on the same lines

Had a bit of spare cash by luck this month, so I've ordered a switch through work. On Sunday I can spend a full day on the car and see if I can get it running ok, trying everything that 's been suggested thus far with a good result all being well

 

[dazzo666]

yeah thats what i ment to say sorry. Water temp sensor. sedis are prone for these all the time, as are the 1.4's

 

[punto-paul]

yeah thats what i ment to say sorry. Water temp sensor. sedis are prone for these all the time, as are the 1.4's

Ah that's ok well I've got my fingers crossed this will be the problem and all will be well

As the poor old Tipo is sat buried under a pile of leaves, and covered in cobwebs. So I best get on it Sunday, otherwise my dad's neighbours will think I've dumped it!!

 

[bluejohn125]

If you do the coolant etc it may be worth replacing the thermostat too... I've changed them on both my Tipo 1.4s in the past. But you will need to figure if it is a temperature / warmup thing... Obviously some signal is getting its wires crossed, but of course it could be connected to the EFI / throttlebody and its wiring, sensors or pipes.

I'm assuming your car has the digiplex box exposed on the bulkhead, and the distributor on the end of the cam block (not the later coil-pack design). If so I've got a spare Digiplex somewhere, but I don't think that's your issue..

 

[punto-paul]

My Tipo does have the Digiplex system, but from what everyone is saying it's unlikely that it'll be the fault as you say.

At the moment the car seems to be running up to temperature ok, the fan cuts in when it should do with no overheating or anything

So I'll leave the thermostat etc.. alone for now, as well as the antifreeze as that was changed before I got car.

I've got my water temperature sensor today, so as long as the rain keeps away I'll get it sorted on sunday

Hopefully I'll find the fault, weather it'll be the switch or one of the other suggestions!!

 

[dazzo666]

Excellent hope this maybe the fix... as always start at the cheapest and go from there...

 

[punto-paul]

Cheers, for the few quid it cost it certainly wouldn't do me any harm to try it

Just hope the rain keeps away now

 

[punto-paul]

Re: 1994 1.4 i.e Tipo Idle problem ( It's Fixed.. I hope, but water inside now.. )

I think thanks to everyone's suggestions, the car is finally running ok

As the weather was rubbish, I popped down to a garage I know and they helped me look in the dry

We checked the all the vacuum hoses and all was well, the air box seems tight and the seal on the spi / carb unit seemed to be all in good order.

The only pipe I could see was split, was the convoluted pipe that takes air from the back of the air box to the inlet manifold.

Unfortunately I hadn't got any convoluted hose suitable nor had they, so I had to leave that for now.
In the meantime we fitted the new temperature switch, topped up the coolent and took the car on a run.

Amazingly the car behaved itself, no revving up and idled nicely!!

I've since noticed the back box is knocking, so it looks as if it need adjusting or maybe a couple of new rubber mounts.

The only other problem I have now, is that under the passenger front floor matt there was a lot of water

Unfortunately it was after I'd driven through a large puddle of water, so can't decide if it was leaking through the scuttle due to the leaves that were stuck under the wipers when it rained etc..

The water doesn't smell of coolent, so that ruled out the heater matrix for now.

I've then checked the carpet, but no damp near the door sill area or from behind the dashboard.

So my next job if the rain stays away is to look underneath the car, I haven't looked yet but did wonder if a rubber bung had disappeared somewhere!!

Never a dull moment :bang: also how good or bad is the 1.4 for Mpg? My car seems to be a bit thirsty, but there again I've got used to the Uno 1.0 I also drive