*NOTE* the car is Euro spec S5... I.E. S4 Engine with Dizze/S3 ignition system


i have a few problems with my car, i wanted to bounce them off u guys i thought maybe u'd know

i'm having hesitation problems...

but not the 3,800 hesitation

this is totally different,

from idle to 3,000 rpm the Rpm is slow....
then from 3,000-5,000 i feel the pull..
then after 5,000 the rpm just pegs there.. and doesn't wanna go more.. just hesitates like hell

when it pegs.. it's not like bouncing a rev limiter... more like a constant.. brrrrrrrrrrrrrrr... and the rpm doesn't continue...

at idle if i rev...

like 10% throttle i can reach the buzzer

if i try to gun it, again pegs at 5,000 rpm

if i'm rollin in 1st gear

and slowly work my way up to 5k

then 6k
then suddenly floor it

the car falls flat on its face


if i'm driving normally... as long as i keep the car floating above 3K it's usable...

but when i leave a traffic light.. it feels like the car wants to die, especially with the AC on I have to slip the clutch alot... till i can get upto about 3,000 rpm... then suddenly u get pushed into the seat all the power comes in one big lump...
it's like i'm making 20hp then suddenly 100hp at 3K then dies again at 5,000





only mods on the car is
cone filter
RB headers
apexi catback
i changed the fuel pump with my walboro 255 (but didn't re-wire it)

I put fuel injector cleaner and 20ltrs of fuel last night...
drove it about 60km's since then... no change as of yet
i changed the fuel filter as well

could it be ignition related? I'm not sure where to tackel the problem from... I could spend money changing the coils, and spark plug wires...

or take out the injectors and have the cleaned and flow tested...



or the fact that it redlines at low TPS % means its ok?

maybe the secondaries aren't firing at all... and the primaries are "carrying" it up to redline under no load...


i was thinking of putting the 550's from my S4 TII into this car but the stockers are 460's.. so i'll be drowning the car in even more fuel.. it's already running rich and backfiring allover the place... my rear bumper is black half the time..

 

I would start by checking the voltage at the fuel pump.

Then check for a clogged cat (or thermal reactor).

 

does this car have a Throttle Position Sensor (TPS)?

also i don't know if that ECU you got in there can display error codes through the check engine light or not, but you may want to see if there are any.

- Aaron

 

the car is practically stock, ur telling me an unwired walboro isn't gotta give it enough gas?! common!

the car has RB headers and an apexi exhaust... no catback present... (airpump is still there tho)


i'm goin back to the garage now, to check for a TPS

i'm wonder if the TPS from the S4 NA is the same as the S4 TII, cuz that's the only one I have laying around...



I also forgot to mention.. that the car has a helluva time trying to start...

if i want it to start.. i can't just crank and crank..

i gotta use technique... and crank in short burts at first and such...

car doesn't wanna idle when it's cold in the mornings.. the rpm seeks, and wants to stall.. i'm guessing that's the cold assist...

once it's warm tho.. it idles at about 1K with AC off.. and 800 with AC on..

 

does the idle drop down from 1k and stay at 800? if so then you should inspect the BAC valve and see if that is working properly.

again, what about the ECU codes? can you check those?

 

well I went and changed the TPS.. made no difference.. plugged, unplugged, and swapped..

I took a video of the RPM as well

first revving under light throttle to redline..

then letting it settle.. and mashing the peddle and seeing the result..



I don't have my LED's handy at the moment.. so I couldn't check for error codes...

i hosted it on putfile.. maybe it can play it..
(video is from my P900)

vid here

tell me what u think

 

well something else i discovered..

my fuel economy is utter CRAP...

it drinks at least 50% more fuel then my TII does... (with less than half the performance as well)


i'm barely getting 10MPG! with little city driving...

 

some ideas would be appreciated...

 

It could be. The engine will run fine without the trailing plugs, but if you lose the leading plugs you lose about half you power. It feels smooth, just real slow. A loose connection somewhere could be making this problem intermittent. Try swapping the leading and trailing parts around (plugs, wires, coils) to see if that makes any difference. Check the condition of all the wiring at the dizzy and coils.

 

thanks NZ... did u watch the video i posted?

will the wires show damage from the outside? how can I inspect rubber sheilded wires?

 

It might be *too much* fuel with the Walbro!
Try this...
Go out and start banging on that 5kRPM wall...
Try and do this right before shutting the car down.
Let the car sit for a few minutes and they pull the leading spark plugs - are they all matte black?
If so, it's running too rich and it's killing the spark.


-Ted

 

hmmm...

yea the plugs are quite black actually...

maybe that's why it's so hard for the car to fire up on start up...

the stock fuel pump is shot tho.... i put voltage directly to it.. from the battery...and it didn't make even a sound


what if I were to use the stock TII fuel pump... would that be lean "enough" ?

I do have an SAFC-II on the TII as well... but i was hoping to use that in combo with my 720CC+Rtek 1.7 combo...

hmmm... decesions decesions....

 

I'm on dial-up, so I didn't bother. How big is it?

Actually I meant to check the low-voltage wiring to make sure it's all connected securely and the wires aren't shorting on anything. But check the condition of the HT leads too. A good test is to measure the continuity on the lead while bending and flexing it.

That pump is definitely too much. A TII pump would be a big step in the right direction, but an NA pump would be much better if you can get one.

 

ya man... the file is less then 0.8mb or so...

it's bareable :P


i'll have to try and source another pump...

would ur average oem Nippon Denso unit be ok?

 

That does sound like it could be igntion break-up. I had a bad miss a while ago that would only occur when cold or under load. As it got worse the amount of load required to cause it got less. Turned out to be a bad spark plug lead.

 

oh wonderful... so much for that :P

btw... the coil (pack?) sittin in the corner by the battery

are the pair of them Unique to the mazda... or would i be able to find a similar component on other Dizzy'd cars.. like datsuns or old toyota's etc.. (like the brake pads are)

if it's unique, then i'll have no chance of replacing them locally...

 

Yeah, try and use a stock Turbo II fuel pump - if it's a rich problem, the problem should shift higher in the RPM range if not disappear.

NZConvertible has a point.
Try this...
With it really dark outside, get the car to run.
Rev the engine while looking under the hood - do you see any arcing or anything glowing???
There should be NOTHING glowing!
The rich condition could also be part of this problem, as richer mixtures are harder to ignite; if the spark plugs doesn't ignite, the spark has to arc somewhere else!

The stock coil is a normal e-core coil.
Almost any modern ignition system should have something similar.
Just to be sure, check the resistance across the primary windings (input side) - it should at least the same as the FC ones or *more*; if you find some coils that are less, there's a chance you could burn your ignitor out.



-Ted

 

thanks TED...

it may well be two problems compounding...

maybe that's why the RPM's are lazy from 1-3 from being rich, and the 5+ is from ignition..


there USED to be arcing at one of the coils.. from the middle of the coil to the terminal..

I pulled them out... sanded and cleaned the terminals and connectors and then re-assembled all of the stuff...

for awhile the car seemed to be running on only 1 rotor... (rear) but that had went away...


one of the coils seemed to have some light corrosion and denting on the outside the other seems like new...

can i just switch the 2 plugs for the T and L and see if that works? or do i have to swap the - and + of the coil packs as well?

 

As a testing method yes, but I wouldn't advise it long term. If the plugs are old I'd just replace them. Old plugs certainly won't be helping.

Hell no!

Try swapping the coils entirely. They're identical, but like I said above it's the leading plugs that are the important ones, so if the leading coil is dodgy you'll see an improvement straight away. Do the same with the leads.

I like Ted's idea too. Glowing, sparking things are fun...