Technical '94 Tipo 1.4ie ignition problem

[RayMK]

My son bought the '94 Tipo 1.4ie about 10 years ago. 3 years ago he sold it to a friend who was in need of a car, then 9 months later I bought it off the friend because it needed a fair amount of MOT work which no one else was prepared to pay for. It has only done about 60K miles. The MOT work was duly done and the car continued to work reliably until mid July this year when it failed to proceed. I had driven into the local countryside with all systems working properly, as they had been doing throughout our ownership. I parked at a scenic spot in wonderful weather and settled down to eat a packed lunch and read a Practical Classics magazine. After about 2 hours I decided to head home. I operated the ignition key in the normal manner and the starter turned the engine completely normally but, instead of firing pretty much instantly as it always had done, it just continued to turn without so much as a cough. I tried again three or four times but nothing changed. It simply did not want to fire. The car's tank was just over half full of recent petrol and it has been regularly serviced throughout its life. I investigated under the bonnet, looking for broken wires, loose connections, leaks and anything else that was broken or displaced. Everything appeared to be fine. I pulled a sparking plug to test for sparks. Absolutely nothing. The AA was called. They turned up within 1.5 hours and conducted basic tests which confirmed the lack of sparks but that the coil was receiving 12Vdc and the crank sensor was pulsing. The car was mounted on the AA dolly and taken to a local garage for investigation. I was happy for the garage (which I know well and trust) to treat the Tipo as a fill-in job. I've got another car, so no bother. The garage replaced the coil with the correct Fiat part but this had no effect on the symptoms i.e. the engine turned over on the starter but did not even cough and there were no sparks even at the king lead, as before. My Tipo has the Digiplex ignition with distributor in line with and at the right hand end of the cam cover (looking from the front). It has standard single point fuel injection. My manual mentions an ignition module fairly close to the coil and battery near the right headlight or inner wing. I can't see any such module or indeed any loose wires if the damned thing had gone AWOL. This makes it difficult to replace!! The main Digiplex box is on the bulkhead/firewall but looks nothing like the absent ignition module. Any comments would be most welcome. I, and my garage, have drawn blanks trying to diagnose the lack go sparks. I may have to get the car taken to an Italian cars specialist or possibly a Fiat dealer after further phone calls to give me confidence that these options may unravel the mystery.

 

[bugsymike]

Engine code 160 A1.046 ?
Many manufacturers around that time used a sort of booster module often fitted to the side of the distributor (roughly the size of a matchbox) to take the signal and boost it for the coil, Fords especially would pack up and companies like Intermotor would do a cheap replacement. I am not familiar with Digiplex. Another type used on some Ford Fiestas etc. was a box with a vacuum advance pipe to it , usually fitted to the bulkhead which did away with the distributor all together. Somewhere in my garage I have one of those. If you can still locate one of those or similar and have a good impulse from the crank sensor it may be possible to operate the coil that way. I assume you don't still have the original ignition parts from pre the "Digiplex" setup?
I have just found this final picture from an old Haynes manual showing location of "Digiplex unit" I thought from your thread that it was a sort of "aftermarket" addition though according to the Haynes it was only on the 1.6?
Seeing in your thread about reading "Practical Classics", I had a Vintage lorry in their commercial section in 1987, a bit of useless information.
If this is any good let me know.

 

[RayMK]

Engine code 160 A1.046 ?
Many manufacturers around that time used a sort of booster module often fitted to the side of the distributor (roughly the size of a matchbox) to take the signal and boost it for the coil, Fords especially would pack up and companies like Intermotor would do a cheap replacement. I am not familiar with Digiplex. Another type used on some Ford Fiestas etc. was a box with a vacuum advance pipe to it , usually fitted to the bulkhead which did away with the distributor all together. Somewhere in my garage I have one of those. If you can still locate one of those or similar and have a good impulse from the crank sensor it may be possible to operate the coil that way. I assume you don't still have the original ignition parts from pre the "Digiplex" setup?
I have just found this final picture from an old Haynes manual showing location of "Digiplex unit" I thought from your thread that it was a sort of "aftermarket" addition though according to the Haynes it was only on the 1.6?
Seeing in your thread about reading "Practical Classics", I had a Vintage lorry in their commercial section in 1987, a bit of useless information.
If this is any good let me know.

Thanks for your reply and attachments. The engine code should be as you've quoted but the car is a few miles away so I can't check right away. The Digiplex is indeed a completely standard set-up, not aftermarket. Most photos of the 1.4ie engine show the earlier distributor and a different ignition system and I agree it is usually only the 1.6 which is shown with the Digiplex and cam end distributor position. My manual (digital copy found on line) is a bit ambiguous on what is fitted to the late model 1.4ie. We bought the car 10 years ago with about 37K recorded, in good used condition with a completely undisturbed engine unit which certainly behaves like a 1.4. In the early 2000s my late wife owned a 1.6 Tipo, so I'm fairly confident ours has not had an engine swap. Yesterday, on visiting the garage, I was surprised that I could not find anything that looked like an ignition module where the manual said it should be. I took a few photos (attached) but may need to go back on Monday to take more, particularly the area to the side of the battery where I may have missed something.

Nearly all 'classics' interest me. I've owned a 1961 Reliant Regal MK6 since 1992. It is still roadworthy but for various reasons rarely gets out these days.

 

[bugsymike]

Your Digiplex photo looks very similar set up including vacuum advance built in, to the Ford Fiestas of that era and by and large, I think it was standalone apart from the pick up sensor and the distributor and rotor arm to direct to individual plugs.
According to the Haynes manual the 1.4 had the module on the side of the distributor like some of the older Ford Escorts etc. and often failed misfiring, but the 1.6 Tipo had it on the bulkhead like yours, so maybe it was a changeover to the more improved version.
The hardback manual (1625) I have is only for vehicles 1988 to 1991 but from my experiences with the Fiesta system in the past it does point towards that Digiplex unit in total failure whereas at the time the earlier versions of Ford ones gave a misfire more commonly.
The Digiplex being a sealed unit not a DIY repair part replacement only if obtainable. I don't know if anyone on Forum has a spare one or the details of readings to test it.
Re the Reliant, in the late 1960s I had a friend who was foreman of the local Honda motorcycle dealers who were also Reliant agents and the boss had an early Reliant with the Girder front forks etc.
This is the Ford version with vacuum advance.

 

[s130]

Attached is info on the Digiplex ignition systems and some diagnostic information.

I've had the crank sensor fail on our 130TC because the sensor wire is clamped to the block and the block heat causes the wire plastic to become hard and brittle.

Suggest you read and test accoring to attached file which includes sensor testing.

 

[RayMK]

Attached is info on the Digiplex ignition systems and some diagnostic information.

I've had the crank sensor fail on our 130TC because the sensor wire is clamped to the block and the block heat causes the wire plastic to become hard and brittle.

Suggest you read and test accoring to attached file which includes sensor testing.

Many thanks for this. It helps me to understand how the system works and the testing instructions will help either me or an appropriate garage technician to diagnose where the problem is. I'll probably have to delegate most of the work because age, health and mobility are ganging up on me. Provided that the Tipo can be sorted out at reasonable cost, I do not want to scrap this car.

 

[jonti]

regarding your updates elsewhere, I have the eu scan software and correct lead to read my 1.6 i.e. If it becomes necessary I could see what could be done to assist. However I would say this diagnostically is probably a last resort after the other diagnostic tests suggested.

 

[RayMK]

Not much progress on my Tipo. We found and bought a known good Digiplex 2 ECU (439M) which is the same as the one on the car. Fitting this did not change the lack of sparks. I've bought a NOS Magneti Marelli SEN8M crank sensor but have not fitted it yet. The car is still at the garage and the battery has now gone flat which means I need to either bring it home to charge or fit a temporary good battery in order to carry out diagnostic tests on the ignition system with a multimeter. I did attempt to do the tests a few weeks ago but with only 3.4V left in the Tipo's battery I could not complete them.
A couple of days ago I made enquiries with a local Fiat specialist to see if they'd be willing and able to get the car fixed. They have not yet got back to me. I have not given up but everything is taking ages!

 

[RayMK]

Just another update on the lack of any real progress on my poorly Tipo. Plan A is still slowly ticking over, that is, the garage will investigate its non-running and report back if they can fix it. They will then MOT it (expires 22nd December) and do any further work if it fails. I'll be discussing it in more detail on Monday. I do have a reasonably generous budget. However, this will not be a blank chequebook exercise. Plan B is to have the car transported to a nearby classic car garage which has the gear and willingness to take this on sometime in February/March 2024. Plan C will depend on the Tipo's fixability versus my budget and could be the end of the road for this one.

 

[bugsymike]

Is there a chance the "new" Digibox is duff as at the beginning of the thread you mentioned the AA tested the coil and the crank sensor and reported all OK?
On the Ford Fiesta with similar set up I had two duff s/h ones before getting a working one, so they are not immune to failure.
Can one of them be tested/repaired?
Obviously with a good battery showing 12.5 volts.

 

[RayMK]

Is there a chance the "new" Digibox is duff as at the beginning of the thread you mentioned the AA tested the coil and the crank sensor and reported all OK?
On the Ford Fiesta with similar set up I had two duff s/h ones before getting a working one, so they are not immune to failure.
Can one of them be tested/repaired?
Obviously with a good battery showing 12.5 volts.

Yes, it is always a risk buying 2nd hand electronics. At £80 approx. a time for the correct 439M Digiplex 2 ECU and at least twice as much for NOS makes this a difficult path to follow, especially as there are so few available. The AA man could not detect any HT activity from the coil but was not familiar with the set-up i.e. whether it required sensors and the ECU to all be functioning before it would work. A new coil was tried by the garage to no avail. With a limitless budget I'm sure the whole Fiat electronics package could be replaced by a modern equivalent modified for this application. My budget won't extend that far and my timescale tolerance also has limits. With luck, one or other of the garages will find the cause of the problem and save the car.

 

[bugsymike]

Yes, it is always a risk buying 2nd hand electronics. At £80 approx. a time for the correct 439M Digiplex 2 ECU and at least twice as much for NOS makes this a difficult path to follow, especially as there are so few available. The AA man could not detect any HT activity from the coil but was not familiar with the set-up i.e. whether it required sensors and the ECU to all be functioning before it would work. A new coil was tried by the garage to no avail. With a limitless budget I'm sure the whole Fiat electronics package could be replaced by a modern equivalent modified for this application. My budget won't extend that far and my timescale tolerance also has limits. With luck, one or other of the garages will find the cause of the problem and save the car.

As far as I recall no ECU basically the Digibox type setup was the cross over from contact points in distributors and a full ECU type system.
What I would do is search the internet for a way of testing the digibox with a Multimeter, I am sure there is something out there.
Having just said that, what is your engine series no. as I have just found a basic ECU set up with pin out data for a Bosch Mono Jetronic A2.2 for Fiat Tipo 1.4 ie with Cat dated 1991-1996, does that sound at all similar to yours?

 

[RayMK]

As far as I recall no ECU basically the Digibox type setup was the cross over from contact points in distributors and a full ECU type system.
What I would do is search the internet for a way of testing the digibox with a Multimeter, I am sure there is something out there.
Having just said that, what is your engine series no. as I have just found a basic ECU set up with pin out data for a Bosch Mono Jetronic A2.2 for Fiat Tipo 1.4 ie with Cat dated 1991-1996, does that sound at all similar to yours?

I have managed to compile a pin-out test schedule for the 439M Digiplex 2, thanks to the earlier posts here for a similar Fiat set-up and subsequently further assistance from members of another forum, one of whom went to the trouble of trawling the net and found an applicable test routine for the Digiplex 2 equipped 1.4ie on a Russian website. The Bosch monotronic has its own ECU for the single point fuel injection, but it's the ECU which controls the ignition which is being investigated. Wiring diagrams were also scrutinised to see if the two ECUs 'spoke' directly to each other. Apparently they do not, but they both take the signal from one or more sensors, the crank sensor being shared, this being the only sensor input to the ignition ECU of 1.4ie Tipos with the Digiplex 2 unit. Some models had another engine speed sensor at the crank pulley but mine is the configuration which only has the sensor at the flywheel. I've left my compilation of the ignition ECU pin-out test notes on the Tipo's seat for when the garage chappy has time to investigate further with a decently charged battery installed.

 

[bugsymike]

Let me know if you want the Jetronic A 2.2 pin outs and readings.

 

[s130]

Yes, it is always a risk buying 2nd hand electronics. At £80 approx. a time for the correct 439M Digiplex 2 ECU and at least twice as much for NOS makes this a difficult path to follow, especially as there are so few available.

£160 for crank sensor! You probably don't want to read this:

Ignition Car Parts sell them for between £20 and £40.

If you have the sensor as new and unused I would send it back. You might get a 10% handling charge but will be over £100 better off!

 

[RayMK]

£160 for crank sensor! You probably don't want to read this:

Ignition Car Parts sell them for between £20 and £40.

If you have the sensor as new and unused I would send it back. You might get a 10% handling charge but will be over £100 better off!

No. The 2nd hand 'thought to be good' Digiplex 2 439M ECU was around £80. I do not want to rush out to buy another one until the ignition fault has been diagnosed and the offending component identified. The NOS Magneti Marelli SEN8M crank sensor was £54 but not yet fitted. Ebay had cheaper crank sensors from Germany but they were equivalent parts and the £20 saving would be mostly absorbed by postage and risk (e.g. wrong part). I sourced one locally and was able to pick it up.

 

[RayMK]

Let me know if you want the Jetronic A 2.2 pin outs and readings.

Many thanks, I'll know who to ask. The fuelling has never given a problem so if we can fix the ignition the car will probably outlast me.

 

[RayMK]

I have not got any further with diagnosing the ignition problem on my '94 Tipo 1.4ie, mainly because age/health are causing enthusiasm to evaporate. Unfortunately I've not found any garages which wanted to take the task on. It is currently still at the garage where the AA towed it to - with their agreement, I hasten to add. Before I let it go, shout if there's any interest on the forum. Bear in mind that the car has not moved since last July and, although it still looks remarkably tidy, the cause of the FTP needs to be found and the rest of the car recommissioned even if it is fixable, then MOT'd. Read the thread for further info. I want to relinquish ownership in the next 4-6 weeks. Reg is M112TEH.

 

[s130]

I don't understand why with the Digiplex info I provided with the multi-meter test information that a competent technician / vehicle eletrics person can not find out what the problem is.

If it is the Digiplex unit that is duff then this could be an issue to find yet another working one but not impossible. One could also consider going back to points or another ignition after market module. That said it would be more work / hassle than just simple parts replacements.

 

[RayMK]

I don't understand why with the Digiplex info I provided with the multi-meter test information that a competent technician / vehicle eletrics person can not find out what the problem is.

If it is the Digiplex unit that is duff then this could be an issue to find yet another working one but not impossible. One could also consider going back to points or another ignition after market module. That said it would be more work / hassle than just simple parts replacements.

The problem seems to be that smaller garages prefer to pick straightforward mechanical jobs these days, and that includes garages which specialise in classics. I've got one more to phone. A bog standard Tipo i.4ie does not appear to attract the interest of many outfits.

I agree that this one is fixable and diagnosis probably would not tax the patience of a competent technician/electrics person. I'm unable because of health and age to take this much further but would be happy to give the Tipo to someone free of charge if they wanted to give it a go. However, it would have to be collected by Mid May. If any such arrangement interests anyone then I'll provide further details, even if the intention is to just to fix and sell or break for spares. Be realistic though. This is not a sought after model and, while it was a fine every day car in tidy condition until last July, it is not a show queen or remotely sporty and has been sitting outside for 10 months untouched. You would not get much return for your efforts, only the pleasure of rescuing a Fiat from recycling or perhaps saving another one if it has spares you need.