Tuning 1368cc 16V FIRE Turbo (T-Jet) Uno conversion

[randomizered]

Have you capped off where the evap cannister used to fit?

You may be getting pressure build up in the circuit if there is no vent at all. Try running with the filler cap off, or make a hole in a spare filler cap that lets the tank vent.

DO you hear any gushes or gurgles when you remove the filler cap after a long run?

If you are not using the evap, as you've said, you may need to install a valve to allow pressures to regulate.

http://www.thinkauto.com/onewayvalves.htm

Kristian

 

[lewey]

I put an old fuel cap on that has a hole drilled in it to see if I had a simple venting problem, but cavitation came on at about 10-15 mins as usual. Before this time everything sounds great and works great. It is always the same; I do feel it is fuel temps then at this point. The swirl pot was almost hot after a blast tonight.

Already tried last night Kritip. The tank has the original simple vent at the top that seems to work OK.

 

[Louie Bee]

Not really come across swirl pot theory but I can't get my head round how the air can escape from the swirl pot while the pumps are running as the fuel rail PRV will be constantly pushing fuel along your orange lines.

Should it not be setup like this to prevent air locks?



Found that here but not read much of it http://www.justanswer.com/ford/3wd9k-04-mustang-v6-adding-eaton-m90-supercharger.html

With your setup I'd guess as the swirl pot heats up, so will any trapped air, thus being pressurised and force it's way to the tank.

while pressurised, if it's going towards the Tee it will effectively fight the fuel rail leakoff path, so the easier path fights the lift pump, which would explain the noisy pump??

Only guessing here but I'd have a stab at returning the fuel rail leakoff direct to tank and independently return the swirl pot top hose to tank (removing the tee).

Was your setup inherited? I think Nathan's setup was running super high fuel rail pressure instead of higher flow injectors IIR.

 

[lewey]

I am kind of screwed with only 3 connections to the pot though. I took the return line off the tank top so I could watch the fuel returning whilst ticking over. With the car sat in the sun before I started her up tonight, the cavitation was apparent almost immediately, I could even hear an uneven idle as the pressure became low enough to cause trouble at the rail. When the cavitation really got going the return line almost stopped returning anything at all. Fuel was seemingly going nowhere.

I know what I'd do if I had 4 pipes on the swirl pot, but as I don't, I'm a little stumped. The return and the swirl pot overflow being joined is obviously not a good idea it seems.

I do have a solution if I haven't sorted by Sunday, which is when my trip starts. That will be to forget the swirl pot completely. Will defo work and won't take long to sort, but could see starvation at Oulton, although the road will be fine.

 

[lewey]

Only guessing here but I'd have a stab at returning the fuel rail leakoff direct to tank and independently return the swirl pot top hose to tank (removing the tee).

I thought that and tried it by running the lines to the top of the open tank. The low pressure pump can't fill anywhere near quick enough and the pot empties in about 30 seconds, leaving the main pump sucking air.

Was your setup inherited? I think Nathan's setup was running super high fuel rail pressure instead of higher flow injectors IIR.

This is all inherited, which is why I don't know what is going on and have only just got round to even working out how it plumbs in. This problem has existed since I got the car actually, even with the old engine. I just didn't drive it enough with the old engine in to remember I had the issue! The old setup ran standard injectors with an adjustable reg at the front set to around 4.5 as you say. I am running it how they ran it, but with the standard fixed 3.5bar reg on the rail.

 

[Louie Bee]

Perhaps ditch the 3 line swirl pot, and lift pump for now and keep your tank topped up on the track. do you have the plastic tank on the filler line on your Uno?

the standard Uno Turbo pump whacks out 12 bar and as you say the T Jet uses less fuel than the Turbo so the standard pump should flow enough for your T jet needs at 3.5bar.

I seem to have 3 bar in my head as standard Uno turbo FPR

Hers one in my gallery from when I broke a MK2

 

[lewey]

Yeah 3bar is what older FIATs used to spec for MPI installs, then it moved to 3.5bar in about 2000 with all the new networked electronics and return-less rails, etc. and seems to have stuck there.

I have a couple of pumps in the garage of unknown specs that I may try out in place of my current ones. I could run a setup where both swirl pot overflow and rail return go into the tank separately as I tested before, but I either need a better low pressure pump or perhaps just a less ferocious high pressure pump.

 

[lewey]

Perhaps ditch the 3 line swirl pot, and lift pump for now and keep your tank topped up on the track. do you have the plastic tank on the filler line on your Uno?

I don't think I have the tank-in-filler thing. I don't think I will need that much fuel in the tank to keep starvation at bay at a guess. Oulton doesn't have any really prolonged corners at least.

 

[Dunc Uno Turbo]

Lewey, congrats! Thats all i can think of!

Watching the Video of you boosting about really makes me wanna get mine on the road! Not far off now!

The only downside to the conversion is how quiet it is compared to the old skool turbo baaarrrp! One thing i love about old turbo'd cars is the nosie.

other than that, perfect job! Looking very factory!

Dunc

 

[lewey]

Cheers Dunc. Yeah, it is quieter. One problem is capturing the noise it makes on a not great, mounted camera. The induction noise is excellent and is the loudest thing you notice when driving until you get road noise at very high speed, yet you can't hear at all on the video. Exhaust noise is set to increase when I replace the downpipe which has a catylitic silencer in it that is so effective you could run without any other exhaust and it wouldn't be too offensive! The "lack" of noise does make your speed feel slower.

 

[lewey]

Got some pump numbers. My low pressure pump is a Bosch 0580464069 (174 L/hr @3bar). This is actually the standard Uno Turbo pump. I have a new spare one of these knocking about too. My high pressure pump is a Bosch 0580254044 (264 L/hr @3bar). The FIAT supplied pump for the Bravo T-Jets is rated for 110 L/hr @3.5bar according to eLearn.

So basically the standard pump is more than man enough, but also as a high pressure pump it shouldn't be being used as a lift (low pressure) pump for a swirl pot. The whole setup seems a little ill thought out to me.

I don't really have a solution with the time I have, so am just going to use the standard pump on it's own, without the rest of the setup. I shall sort this tomorrow eve and test it on a quiet roundabout.

 

[Louie Bee]

If you have the turbo tank you should be OK. the MK2 tank is said to better baffled but I don't know how to tell them apart.

Do you have an air / fuel meter plummed in?

 

[lewey]

If you have the turbo tank you should be OK. the MK2 tank is said to better baffled but I don't know how to tell them apart.

Do you have an air / fuel meter plummed in?

I have the turbo tank. Looking through the top, the baffling looks good to me and I'm pretty confident it will be OK, but the previous owners wouldn't have done all the work they did for a laugh, so there must be a limit.

Don't have an air/fuel gauge. Only things I have working at the moment are coolant temp, oil pressure switch light, rev counter and vacuum/boost gauge. Tempted to replace oil switch with original UT pressure sensor, so I have a proper range to look at. Will investigate whether possible tonight. Can't do both, don't have tee-piece.

 

[lewey]

I removed all the swirl pot plumbing and the big pump. Connected up and still really bad, couldn't believe it. Removed the front filter leaving just the tank, pre-filter, pump, rail and return to top of tank. Still bad, in fact it seems worse. Bit the bullet and replaced the pre-filter of which I have a new FIAT spare fortunately. At first this did seem to clear it. I drove for a few miles and it was only making a little noise every now and then. Few miles later and it was as bad as ever.

I have to presume that there is just loads of crud in the tank. New filter fixed for a bit until it blocked that up too? I have pretty much nothing else left to suggest. I tried putting the pump outlet into a petrol can and it wasn't coming out with any real gusto, so that narrows it down to something in the tank or the filter.

I've got a full tank of fuel which is very annoying and makes the task so messy. Going to pump all the fuel into my Panda and see what I can see in there and give it a clean out if necessary. For some reason I feel I am going to be unsatisfied with what I find.

If someone lit me right now, I'd go up like a torch...

 

[lewey]

Wired up switch to pump so I could turn it on and off myself in preparation for pumping fuel out. Turned it on without engine running and observed flow as OK into a jerry can. I have decided that actually the flow is not as bad as I thought coming straight from the pump, it just seems a little low when coming out of a large pipe without the usual 3 bar pressure. Hooked back up to the system and ran it without the engine running. Sounded good, so left for 10 minutes and there wasn't any problem. Started engine which was fine and it kept sounding OK for a couple of minutes. I gave a blip of the throttle and shortly after the cavitation began to creep in again. It appears that the blip excited the alternator which then means more power to the pump (an audible difference) and the extra speed at which it spins causes the cavitation.

I'm pretty lost as to what to do and frankly a bit unwell from all the petrol I've consumed today so I'm going to call it a day. I've only got tomorrow to fix it before my trip into Wales, so would appreciate any ideas.

 

[Louie Bee]

Only faults I can think of without the swirlpot and second pump in the equation are...
fuel pressure regulator fault
pump
fuel lines
in tank blockage
broken tank vent (perhaps always open).
filter inverted.

Bet I’m wrong


Now for the spill... :chin::shrug:

The standard line is 12 bar if unregulated not 3

Did you look into the tank by removing the return / level sender under the rear bench? It twists off but be careful removing the return line as it snaps all too easily.

You’ve not overlooked anything like the 12mm pipe coming off the tank being coolant grade or kinked? It's not a common thickness for fuel line and if it's the original or wrong spec it may be past it's best internally. The original is braded.

I've managed to slip 10mm fuel line onto the tank outlet just to get the car running, but it should be 12mm all the way to the pump.

That’s why the rear filter is so hard to get an alternative for as it's oddball size. Many Unos run without it. Sure you fitted it the right way round?

From memory the original fuel line goes 12mm before pump, 10mm until it enters the car, then 8mm rigid plastic through the car and then back to 12mm in the bay. Return is similar but I think it's 10mm where it fits to tank. I found a big kink in my 8mm section which probably occurred during the reshel...

If still doing it ahead of torching perhaps try an SPI Uno fuel system with the in tank pump and uprating the pump?

 

[randomizered]

I'm afraid I can't be of much more help..however a few questions:

1) Pre-Filter? A filter on/in the pump housing assembly? I though only returnless setups, ie. with the return line in the tank and just one line to the injector, ran these? Am I wrong? Not used to Turbo Uno stuff at all.

2) Since the re-plumb, have all the glugging noises gone but the issues persist?

3) Are you 100% sure this is a fuel issue, and you're not looking in the wrong area altogether?

4) Was the original T-Jet pump returnless or return?

I very much doubt the tank is so full of crud it's blocked the filter in 15 mins. I take it the old one removed didn't give massive warning signals as to rust etc. in the fuel.

Things to try:

Stick a fuel pressure gauge on so you can see if pressure is causing an issue at all.

Fit the original pump if you have it? Simple fit? SOME ECU's run PWM on the fuel pump to actually vary pressure electronically. I know naff all about the T-Jet ECU but could it be doing this?

Stick up some logging results anyway..it may lead to other trails of thought.


Sorry a lot of questions and not many answers, but maybe give some more ideas

 

[lewey]

Only faults I can think of without the swirlpot and second pump in the equation are...
fuel pressure regulator fault
pump
fuel lines
in tank blockage
broken tank vent (perhaps always open).
filter inverted.

Bet I’m wrong


Now for the spill... :chin::shrug:

The standard line is 12 bar if unregulated not 3

Did you look into the tank by removing the return / level sender under the rear bench? It twists off but be careful removing the return line as it snaps all too easily.

You’ve not overlooked anything like the 12mm pipe coming off the tank being coolant grade or kinked? It's not a common thickness for fuel line and if it's the original or wrong spec it may be past it's best internally. The original is braded.

I've managed to slip 10mm fuel line onto the tank outlet just to get the car running, but it should be 12mm all the way to the pump.

That’s why the rear filter is so hard to get an alternative for as it's oddball size. Many Unos run without it. Sure you fitted it the right way round?

From memory the original fuel line goes 12mm before pump, 10mm until it enters the car, then 8mm rigid plastic through the car and then back to 12mm in the bay. Return is similar but I think it's 10mm where it fits to tank. I found a big kink in my 8mm section which probably occurred during the reshel...

If still doing it ahead of torching perhaps try an SPI Uno fuel system with the in tank pump and uprating the pump?

Louie, you have pretty much described my thoughts on the matter.

First, I'll answer the questions. I have had the level sender out many times to look in the tank and have been running the engine/pump with it off with fuel lines going into open tank so I can inspect the flow. The gauge of fuel hose is correct and large as you say going into the pump. It has a stretch of about 4 inches coming from tank to filter and a 3 inch bit going into pump. I've had both pieces off during my experiment and found no problems. It is braided as you say. The filter has arrows on it and is brand new on today. All the lines are decent thickness and are at least the size of the pipes that are on the donor engine too. The setup is now basically factory UT, with original parts and all. The pump is new on today. I've got a spare rail. on my other manifold, so I changed over the regulator, without a good result.

So we are basically left with an in-tank blockage or a broken tank vent. So we are presuming the system actually relies on the vapour pressure in the tank to feed the pump adequately. For me, this is the most likely answer since I never seem to create any pressure that I notice when taking the filler cap off for example. Seems odd that more people don't suffer from the issue, given how sensitive the pump seems to be to a lack of supply. How might I go about testing this? Presume the tank has to come out to sort.

I find it difficult to imagine a blockage that would prevent flow yet allows an enormous amount of fuel through a lot of the time. i had the main line off the tank which I held with my finger whilst I replaced the filter. No indication of a blockage or evidence of anything in the filter which allows water through it from the sink tap at a high rate.

The reason I get slightly variable results, like when I tried the pump into a can and it seemed poor and was noisy, then later it seemed OK, is because of how fast the pump spins. If I have just stopped and the battery is in great charge, the high voltage makes the pump spin fast and causes the problem more readily. I then mess about for a while and start and restart the engine and then repeat the same experiment, the pump behaves a little better simply because it is now seeing 12V instead of 12.8V or perhaps 14V when the engine is running and the noise and flow is at it's worst. This says to me that the issue is certainly a marginal one and there is almost enough supply to the pump at least!

I like the idea of using spi in-tank setup, I just don't have the parts and the time at the moment. I am most concerned about finding any solution before my trip.

 

[lewey]

I'm afraid I can't be of much more help..however a few questions:

1) Pre-Filter? A filter on/in the pump housing assembly? I though only returnless setups, ie. with the return line in the tank and just one line to the injector, ran these? Am I wrong? Not used to Turbo Uno stuff at all.

2) Since the re-plumb, have all the glugging noises gone but the issues persist?

3) Are you 100% sure this is a fuel issue, and you're not looking in the wrong area altogether?

4) Was the original T-Jet pump returnless or return?

1) The tank has a simple outlet on the bottom. There is a normal metal inline filter and then the pump after another little run of hose.

2) Glugging all gone. That was the swirl pot. Just noisy vibrating pump now.

3) Actual engine performance is OK at the moment. There is a direct link with the pump noise and either a lean out condition or lumpy idle. The pump is clearly not healthy with the noise it makes and will leave me stranded at some point. The pump can struggle to pump fuel properly when outlet not even connected to rest of car and the battery is in good charge. I have 3 pumps, they all do it

4) T-jet is a return setup.

I very much doubt the tank is so full of crud it's blocked the filter in 15 mins. I take it the old one removed didn't give massive warning signals as to rust etc. in the fuel.

None observed. Old filter looks perfectly clean.

Things to try:

Stick a fuel pressure gauge on so you can see if pressure is causing an issue at all.

I tried to earlier, but a terminal on the pressure sender broke and I don't have a non-electrical one of right scale. I know there is a pressure issue as I have observed myself by taking the top off the tank and putting the return into the hole. Very little petrol returns to the tank when the pump gets noisy and begins to stop flowing.

Fit the original pump if you have it? Simple fit? SOME ECU's run PWM on the fuel pump to actually vary pressure electronically. I know naff all about the T-Jet ECU but could it be doing this?

I am using standard pump, filter, fuel line diameters and all of it new today! I have never found or read in any manual of a FIAT ECU using PWM or other pump speed control method. I know people say they do, but I have actually measured the models in question and they all just turn the pump on or off, including the return-less ones which regulate mechanically in the tank. I eliminated the electrical supply issue anyhow today by fitting a switched live to the pump that I can turn on and off in the cabin.

Stick up some logging results anyway..it may lead to other trails of thought.


Sorry a lot of questions and not many answers, but maybe give some more ideas

I really don't have a problem with the engine, just the fuel pump. It makes more noise than the exhaust!

Appreciate the brainstorm from you and Louie. The only plan of action for me at the moment is to remove the tank after draining it and having a proper look in there for a mystery blockage. I agree that it seems odd or unlikely Kristian, but all my experiments so far leave it as the only unexplored item in the fuel supply chain.

 

[Louie Bee]

These pics show the vent (smaller item)

#

it screws into the top of the tank near the level sender but can’t remember how close. If you can find the end of the pipe (if still attached) blow down it and you should have a little resistance then freeish air flow (bit like blowing up a balloon). If your brave and fancy more vapour try sucking as it’s a 2 way valve. My MK1 don’t have the pipe any more must have fallen off. No need to remove but take the fuel filler cap off first so you get free airflow. Don’t suck if you heard bubbles up the filler neck but I bet your tank ain’t brim filled atm.

Kritip, the Uno Turbo’s pump is external fed from a 12mm line that exits the front bottom of the tank. God knows why the front as the fuel gets pushed to the back at low tide when booting it.