Frequently asked questions about FIAT Tipo 16V

No spark at the plugs?

Andy Giles' Tipo would not spark when turning over thus the car would not start up. The battery, distributor, high tension leads and spark plugs were all okay. However the problem was eventually traced to the crank position sensor. The thin wire connecting it to the ECU had been frayed by the cam belt pulley and it had eventually snapped.

My car would turn over but not start. There was no spark at the plugs. The signals to the ignition module were okay but there was no signal from the ignition module to the coil. A new ignition module was fitted and the car started. The ignition module is a small black box about the size of a packet of cigarettes that is bolted to the underside of the ignition coil. It has a seven pin connector plugged into it. FIAT only sell it complete with the ignition coil for about £150 but the ignition module can be brought from independant garages.

Starting Problems?

Roy Tomlinson had difficulty starting his car from cold. This was traced to a hairline crack in the distributor.

Karim Kassir had difficulty starting his car when it was very cold -20oC. This was traced to faulty engine temperature measurement device. This sends a signal to the fuel injection electronics telling it how cold it is and how to set up the fuel/air mixture. Now the engine starts even below these temperatures!

Steven Cooper says that this was a wiring short circuit caused by a wiring insulator rubbing against metalwork through split in the grommet at the bulk-head. This blew the fuel pump relays. Fixed by replacing the wiring and relays.

Why does the car does not idle when cold?

If the revs rise and fall at tickover when the engine is cold then suspect the cold start valve (solenoid). It's a mini coke can sized silver cylinder close to the throttle actuator, where the hose from your air filter enters the engine. Its got a wire coming from the top and its a stepped solonoid motor which varies the amount of air that the engine gets. This acts like a choke allowing air to bypass the throttle butterfly when the engine is cold. I had a problem with the engine not running fast enough when cold and was caused by the valve failing and sticking shut.

It you leave the ignition on without starting the engine the solenoid is switched on the whole time. If left for about an hour (I was cleaning inside of car with portable vacuum cleaner) it overheats and sticks. Worth bearing in mind as it's £100 to replace.

Apparently the tolerences in it are very small so any dirt that gets into it will cause it to get stuck which results in an engine that won't run when cold. If the valve has simply stuck and not burnt out it can usually be freed up by cleaning it thoroughly in solvent. WD40 can be used as a quick fix, it washes out some of the carbon deposits and lubricates the solenoid. A longer lasting solution is to clean the solenoid with a carb cleaner.

My car won't idle properly when cold and overrevs when hot, why?

Calvin Jones' Tipo 16V had this problem. It stalled when cold and also ran a little rough generally with an initial "hiccup" before launching itself. The problem was relieved somewhat by cleaning a blocked injector. Calvin thinks that the problem is still fuel related since that after using Redex to clean the injectors the cars performance has improved. Calvin may try using ultrasound to clean the injectors fully before even thinking of replacing them as they cost £162 each. Calvin is also thinking of cleaning the fuel tank in case there is any rubbish in it and then possibly investigating the fuel pressure regulator.

Alexis Grant's car had been misbehaving for the last two weeks. It would cut out, flood the engine when cold and when hot idle at about 2000rpm. It would also have surges when driving. Alexis took is car to NJS to be looked at. NJS used their Fiat/Lancia ECU diagnosis tool to find the problem.

The problem is caused by a faulty coolant sensor. There are three coolant sensors on the Tipo, one that controls when the fan switches on/off, one for the dashboard gauge and one for the ECU. On Alexis car the sensor for the ECU was reporting the coolant temperature to be hotter than it really was. The coolant coolant sensor for the ECU sits underneath the idle valve, it has a blue clip and it quite awkward to get too. The unit needs replacing with a new one, which is about £30. Once replaced the ECU gave the same reading as the gauge on the dash board.

Alexis also found out that the J plate 92 ECU differs slightly from the K plate 93 and that his throttle position sensor which is found at the end of the plenum chamber should have read about 0.2 on the ECU when idle and his was way out. Now Alexis's car idles wonderfully.

Also check the condition of the distrbutor cap and rotor arm.

What ignition leads should I buy?

There is an extremely good article on the web. This details the different kinds of ignition leads, how ignition leads actually work, which manufacturer claims have scientific backing and how not to waste your money. Well worth reading.

Why won't my car rev to more than 4000 rpm?

Alex Wakefield says that when his did this he added a couple of bottles of STP injector cleaner from Halfords into the fuel tank. This seemed to do the trick and he thinks it might have been dirt pulled through the fuel system.

Andy Forsdyke says that where the coil lead went into the coil on his car was all burnt and corroded. He cleaned up the coil and replaced the distributor to coil lead and it fixed the problem. Steven Cooper says that he replaced the angle (TDC) sensor although it still happens occasionally when cold. It is the gap and not the sensor that's important. The car wouldn't start if it was faulty. The TDC sensor is positioned at the crank pulley. The pulley has 4 teeth. Position either of the teeth exactly center of the sensor and use a feeler gauge to adjust the gap. The sensor can also be adjusted vertically if necessary. If the gap is too small, it acts as a rev limiter. Keep the gap to betwen 0.6mm and 1.0mm.

It is possible that the distributor is not set in its correct position - this will not affect the timing but it will affect the distance the spark has to jump from the rotor tip to the output to the HT lead - in time this causes erosion of the tip of the rotor and the output 'posts' inside the distributor cap.

Why is my car only running on 3 cylinders?

Karim Kassir's car had some trouble with the fuel injection system. One of the injection valves got stuck and the engine only ran on three cylinders. Karim took the car to the garage and had it fixed cheaply. The mechanic just took a piece of wood and tapped on the injection valve. He then gave Karim a can of injection cleaner and since then the cars been running again on all four cylinders.

How do I remove the ignition module?

The ignition module is a small black box about the size of a packet of cigarettes that is bolted to the underside of the ignition coil. It has a seven pin connector plugged into it and takes inputs from the crank position sensor, the distributor sensor and the ECU and charges the low voltage side of the ignition coil. Should you wish to replace it follow these instructions.

The module sits underneath the coil at the front right of the engine. There are two leads connected to the top of the coil. The first lead is the HT lead that joins the left hand side of the coil to the distributor. Simply pull this off. The second lead is a 4 pin plug that plugs into the right hand side of the coil. Make sure you release the little catch on the right side of the plug before you try to pull it up. Once you've removed these two leads undo the two bolts that hold the coil onto the side of the battery tray using a 10mm socket. Gently lift the coil forwards off the two bolts, don't let go of it. At this point the ignition module that is attached to the bottom of the coil is still attached to the wiring loop via a large 7 pin connector. The lead from this connector comes up the front side of the coil. To unplug this connector rotate the coil 90 degrees away from you. Squeeze the metal spring clip that hold the connector onto the ignition module and gently pull it off. Once this is done the coil is completely disconnected. The best way to remove it is to lower it down through the engine. The depth is too far to lower it all the way to the floor. If your doing this by yourself you might want to rest the coil/module on the lower radiator pipe before putting your hand up from underneath the front bumper to grab it. Please be careful not to drop it on the floor. Once the coil/module has been removed from the car turn it upside down and undo the two screws that hold it onto the coil. The back of the module will be sticky as it's a gel to dissipate the heat to the coil which acts like a heat sink.

How do I prevent my car from pinking?

Martin Hodges asks why his engine pinks in all gears at low revs but stops at higher revs. He's using super unleaded fuel. Alex Wakefield says his suffers from the same problem. Alex says sure you use 98RON superunleaded (which I think you can only get at Shell) and take the car out for a dam good thrashing. It works wonders. Also try some of the fuel additives that are available, such as injector cleaner to help the flow of fuel, they do help, especially if the car hasn't been used in the way it should for some time.

How do I adjust the idle speed?

The ideal idle speed should be about 850 - 900 rpm. Nareman Virk says to adjust this you need to warm the engine up. Do not adjust the idle if the fan has cut in - wait for it to switch off. Now, disconnect the small clip switch on top of the idle valve, with the engine running. Secondly, adjust the small screw next the the idle valve until your revs rise to 850 rpm. It helps if there are two of you doing this - one adjusting the screw, the other sitting inside looking at the revs. (alternatively, long arms also help!). When you have attained perfection, re-attach the switch and your car should be idling in a state of harmonious tranquility with all existence!

Does a fuel pressure regulator improve performance?

Alex Neagu would like to know whether fitting an adjustable fuel pressure regulator would improve performance? Does anyone have an experience of having one fitted?

As far as I can see, simply increasing the amount fuel going into the engine will not necessarily improve performance as it will need extra air to combust properly. If extra air is not supplied then the closed loop system will detect the excess unburnt fuel in the exhaust gases and lean up the mixture.

My car has had one fitted but only because the larger Jaguar XJ6 throttle (50% bigger area) allows far more air into the engine. Extra fuel is thus needed otherwise the engine runs lean and produces less power than normal. Increasing the size of the injectors would allow more fuel in but this is expensive option and not very adjustable. A better approach I found was to increase the pressure in the fuel rail. The standard fuel pressure regulator fitted to the Tipo 16V is actually a FORD Zetec unit and is not adjustable. I had an adjustable version fitted by a garage as it is extremely difficult to get to. The unit itself cost £125 + VAT

Richard Ellingham says spend your money on something else. All these valves do is replace the standard manifold referenced fuel pressure regulator, with one with a higher diaphragm spring tension. The valves therefore increase base line fuel pressure, but under hard acceleration maintain a slightly higher pressure, hence why FSE call them snap response valves. They are meant to have their main effect on heavy acceleration. People who he knows have had them were never impressed.

The reason for fitting one is if your engine is breathing more efficiently, then your mixture maybe lean, so increasing fuel pressure will allow more fuel to be flowed for each injector opening and return the air fuel ratio to the stiochemetric ratio. However it's not as simple, even though it can be effective for a minor modification.

There is no need to buy a different valve. this may be crude, but it has been advised in CCC magazine, and in modern engine tuning by G. Bell, the standard valve can mildly be squashed between two sockets, to increase the fuel return spring, and up the fuel rail pressure. However none of this takes into account of the quality of air fuel mixing into the cylinders at different rpm levels, neither does it help out he ignition system, as ignition advance angles will no longer be optimum.

Is there a wiring diagram available for the ignition system?

Many thanks to Alex Neagu who sent in this ignition system wiring diagram for the Fiat Tipo 16V. He translated it and I tidied it up an awful lot. It's rather large at 211Kb and 1013x1483 pixels in size. As a comparision, here is the wiring diagram for the Lancia Integrale 16V for the Tipo 16V.

What spark plugs do you recommend?

Mike Jukes uses the NGK 4 prong type which he thinks in theory are better than splitfires and they seem to work.

Roy Tomlinson says try Bosch Super 4's as they've passed his doorstep challenge. They do work and make the car feel a bit crisper!

Nareman Virk says that he uses NGK V-grooved (BPR-7E) because he says they're the best.

Why does the engine cut out when hot?

When the engine gets to about 70 degrees celcius it cuts out and won't start again until it has cooled down to below 40 degrees celcius. This problem turned out to be the crank position sensor that failed when it got hot. It had infinite resistance when measured with an Ohm-meter and it should have none.

Which injectors does the Tipo use?

The tipo uses green injectors. These are the same as those used by 16v Integrales and Ford Cosworths. The cost about £70 + VAT each and can be purchased from places like Demon Tweeks. Out of interest the Fiat Coupe uses beige/yellow ones injectors which flow less fuel in a given time.

Unfortunately it's not the colour of the injector that determines the flow rate, oh no that would be far too sensible. The flow rate should be marked on the side of the injector.

My throttle is sticking open how can I fix it?

The throttle may stick, causing the revs to stay at about 2500 - 3500 rpm even when the throttle pedal is fully released. This usually happens when the throttle is slowly released. This can be quite un-nerving and potentially dangerous. Blipping the throttle is usually enough to temporarily cause the revs to drop back to idle.

If it only does this when cold then it might be a dirty cold start valve. However it is does this when the engine is hot then it's most likely that either the throttle butterfly spring is dirty and sticking or the actual butterfly is sticking against the sides of the plenum chamber. If it's the butterfly spring then simply spray it with a few coats of a penetrating oil such as WD40. It may need a few coats to fully soak in and free it up. If this does not work then remove the rubber flexi section off the end of the plenum chamber, you should see the throttle butterfly now. Use carb cleaner to remove the build up of carbon deposits that are causing it to stick to the sides of the plenum chamber.

Why does my engine take a long time to start up when cold?

If the weather is cold it may take the engine a while to start up. Replacing the spark plugs, distributor cap, rotor arm, ht leads, and distributor will make no difference. However if you turn the ignition off and then quickly back on it will start straight away.

This could be caused by the air flow meter. It sits on the left of the plenum chamber at the back under the brake vacume connection and has a brown clip on it.

Why do I get blue smoke after the engine has not been used for a while?

If the cars lets out a puff of blue smoke for about 5 seconds when started after it has been left unused for a while then suspect the cam cover seals. Oil can get to the back of the plugs and, if you leave the car long enough, it gets past the plugs seals (which are optimised for sealing in the opposite direction) and into the combustion chambers.

What order should the ignition leads be connected?

I've done this twice now, removed all the leads off the distributor and forgotten what the correct order is. The firing order is 1-3-4-2 so the leads should be connected as in the picture below. Starting anti-clockwise at the lead nearest the sensor. It might not be clear from the diagram so viewed from the NSF of the car top left is 1, bottom left is 3, bottom right is 4 and top right is 2.

Where can I get alternative distributor and rotor arms?

If you go into Halfords it does not list the Tipo 16V as one of the cars they cover however they do sell parts that fit perfectly. The rotor arm is HRA521 and the distributor cap is HDC513, both are halfords own brands

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