General 1.4 16v running 1.2 inlet with 1.4 injectors,wierd running. help !

[Xsisley]

i know a 1.4 16v isnt a cinq or sei engine.
but you guys love them and see to put them into cars and mess around with them lots.
so heres a problem for you ...

in my old style panda i have just put a 1.4 16v superfire
(had a 1.2 16v turbo b4(things broke))
iv added 6spd box and other stuff.

im running the engine on a mk1 1242 16v punto inlet and throttle
and using all the 1.2 16v punto wiring loom
i have put the 1.4 injectors into the 1.2 fuel rail.
it starts fine
everything seems good. but when you rev it it has a juddery delay before the revs pick up.
i went for a very small test drive this morn.
as i pulled out it stuttered loads and then it kicked into action and i wheel spun all over the place, and then it did the same as i went into 2nd.

any suggestions.
should i check the timing is right ??
tick over is also a little low when its warmed up. but it doesnt stall.
the exhaust is all 2" , with a 4.2.1 manifold and a small fairly well flowing cat and one very flowing backbox .

could it be throttle body too small ?
timing out ?
exhaust pressure ?

please do your usual magic and help guys. !!
thanks massivly in advance !

aran.

 

[Xsisley]

could it be crank sensor placement ?
i used the 1242 16v crank pulley and sensor with that wiring loom.
and i thought both the 16vs had the same oil pump/sensor position. ??

there is no probs with the alt belt and panda mount.


aran.

 

[arc]

what is your fuel pressure like, are you using a rising rate regulator?

the 'bogging' down when you accelerate could be a sharp lack of fuel, my car does that if i tune the acceleration enrichment too low (or too high as well for that matter!)

try removing the vacuum hose that runs to the fuel pressure regulator (but cap the tube else the MAP sensor will get upset) and see what it does

 

[randomizered]

what ecu is it, the 1.2 16V?

Crank sensor placement is the same so that isn't an issue.

has the ECU been remapped?

As arc said, whats your fuel setup? Did you keep the return line, or are you runnign a non-return setup? If its a return setup, is the pump good enough?

I'd be looking more at ecu issues though.

Exhaust should be fine. My 1.4 runs a SS 4-2-1, with a two inch bore and flows even freeer than yours if you get my meaning.

Does it do this warm and cold?

do any warning lights come on?

If its a 1.2 16V inlet, there is no map tube its built into the inlet temp unit

Bogging down can also be too MUCH fuel as well.

You MAY need to recalibrate the TPS.

The wheel spin may be normal, i can spin mine up and my wheels are 6" wide with some good rubber on. If you have standard panda wheels, then When i had the 1.2 16v in, the 13" sei alloys with pirelli rubber were lethal!

Lots of ideas and lots of questions

 

[Xsisley]

ok the ecu is the 1.2 16v one.(standard)

i have got a return pipe to the tank.
and i have bodged the 1.2 16v fuel pump into the tank.
(worked ok on the 1.2 16v turbo)

i rekon its fuelling somewhere
i will play with the pressure regulator pressure pipe. and maybe block the return for an experiment ???

thanks for help guys !

will go play !

 

[arc]

no worries, good luck

I wouldn't block the return though.. pressure will go through the roof

 

[randomizered]

yeah, only block the return if you run a pump that returns to the tank like some of th emodern ones do, kike the 1.4's and my 1.1 mpi sei pump.

Why did you ditch the 1.2 tub?

Kristian

 

[J333EVO]

I think its the injectors at fault, well not so much the injectors but how you are driving them.

The 1242cc engine uses older style injectors, whereas on the 1368cc engine it uses more modern piezo type injectors, so the duty cycle/duration etc will be very different from the 1242cc injectors. I do not know but you may even find the resistance on the injectors is different, it can be problem when trying to run injectors from different cars on your own, the Cosworth and integrale although running same ECU run different resistance rate injectors.

Therefore the way your 1242cc ECU is trying to run the newer style injectors is not compatible.

I would try some 1242cc injectors and see what happens, I would say that the engine would run as it should without the cutting out/hesitation you are experiencing, but it would still be preferable to get the fuelling checked on a r/r to ensure its all OK.

For the record as we use a 1242cc inlet manifold on our 1368cc engine we used Bosch black injectors (older style) from a MG Maestro IIRC.

 

[dave]

The 1242cc engine uses older style injectors, whereas on the 1368cc engine it uses more modern piezo type injectors, so the duty cycle/duration etc will be very different from the 1242cc injectors.

should i be using 1.2 injectors too then?

 

[randomizered]

I can happily run the two different injectors, but i do need to adjust the pulse width to correct the afr. On the stock ecu, it would probably need a remap to correct it, but i think using the injectors after that should be fine. they are the same resistance

I ran the 1.1 mpi unmapped ecu with 1.2 16v engine and injectors fine as well.

Still worth a try swapping them, I think they should still run the eninge, but at least check the afr isn't too lean before giving it some stick.

Kristian

 

[dave]

ah mine got mapped, oggy was about 2 hours sitting at the desk writting my map, an fuel line was spot on, so i should be ok then?

 

[randomizered]

yep, no probs. The injectors have a lot of head room, and can potentially provide a lot more fuel that they do. My 1.4 injectors don't normally see abouve 45-50% duty cycle, and they can be drive up to 80% all day long with no issues

 

[Slosei]

On my old cinque i did have a similar problem but the injector light came on only when i reved past 5500rpm had it on diagnostic and came up as injector fault so i used punto gt injectors which i already had which are too big but turned down the fuel pressure a bit think 2bar and it run fine then the day after i turbod it and got a whole new set of problems

 

[Xsisley]

hmm so i should play with injectors..

i am going to double chek the timiing on the belt.
just becuase it wud be annoying if i found it was one notch out later on
after play with fueling.

so do we all think it would run ok with the 1.2 16v injectors ????
no too lean. the ecu should sort AFR out ??

sounds like somthing worth a try.

arc, i did block the return. the pressure didnt go through the roof.
it poped the blockage and went all over the engine bay, hahaha

no harm done.

thanks guys VVVV helpful !

 

[Xsisley]

just checked the timing !
its fine.
so its gotta be a fuel or ignition kinda thing !

iv stripped the manifold off and will go try the 1242cc injectors in a sec.
then if that works better i will try get some of the MG Maestro ones. sounds good.

thanks guys !!
aran.

 

[randomizered]

hold off on the mg injectors though. The only reason Emma's could run those, was because it was an Emerald ECU and mapped. You will have the same potential problems as running any other non 1.2 16v injector on the 1.2 ecu without mapping.

Could be something else though.

Kristian

 

[Xsisley]

ok iv now put the old 1242cc injectors back in.
runs alot better but still not right.

revs better.

but you can still get stuck in juddery low revs by opening the throttle quickly.
but its deffinetly alot better with these injectors.

what do you guys suggest ??

is it possible it wasnt running right on the 1.4 ones due to an electrical difference the injectors, but now its running ok. but not quite right due to them being to small. ??

going in for MOT 2 morrow. fingers crossed ! runs well enough for that.
what other injectors can i try ??

thanks guys !!
aran.

 

[J333EVO]

Good progress is being made, I thought it would run better on the 1242cc injectors.

I would retain these injectors and get the car mapped to suit, should cure any irregularities in running.

Another reason is I know you said you are suing the 1242cc inlet manifold so you are using the 1242cc fuel rail as well?

If so the 1368cc injectors will not fit the fuel rail correctly as if you sit them side by side you will see that the size of the injector from rubber O ring to the tip is different and this could also have lead to the running problems.

 

[Slosei]

Just to suggest. Besides getting it remapped and on rollers, what id try next is to get an adjustable fuel pressure regulator a FSE one is good.
as it is now the ecu once its past the closed loop system (4k rpm iirc) the engine will be running slightly lean with you having more CCs thank what the ecu thinks could be wrong
find out if the flow rates are different between the 1.2 and the 1.4 fuel pumps.