Ok basically just done an engine build with a few mods and having a few teething probs at the mo spec is as follows

v1 sti
v3 block
v5 sti heads
full 3"system no cats
tubular headers (heat wrapped)
k&n induction
front mount
z32 maf
800cc injectors
sx fpr
power fc
fuel pump
7 b plugs
tdo5 18g

had it mapped yesturday by jgm and it made 279.8 bhp as it was missing when revving ? simon said it was a coil pack(s) have now changed them all and exactly the same?
new plugs are also in aswell and am now running out of ideas?
it drives lovely but when you really use it it keeps pulling back slightly.
on idle its fine but for instance if you hold the revs at 2000 rpm at standstill it misses and misses more the higher the revs are held?
the hand commander also got to a reading of 21 is this good or bad?
any ideas would be much appreciated as i have now run out of ideas? also the coil packs are absoloutely roasting when you take them out (10) mins after driving i know they get hot but i couldnt even hold it hot?
hope thats enough information to hopefully help as i am all out of ideas

thanks james

 

i know it an obvious one but ere the plugs correctly gapped.

 

yep i checked them yesterday

 

try another set of plugs ?
i have had it before where new plugs straight out the box are ****ed

 

i second that

 

As above, this has happened to me on two occasions. Also the commander reading of 21 may not be picking up det, just engine noise or something, and depending on how Simon set it can be quite normal. Think it is set higher on classics for some reason but the man to ask is Simon obviously. Also are the replacement coil pack new or second hand?

 

did you use the correct head gaskets, and are the heads def sti
the missing normally plugs.

check them for cracks, i've had a couple do this around the necks

my engine has no bottom end grunt till 2/3k then boots like hell
still made 317bhp & 313ftlb but i fitted uk heads & sti v4 pistons + an uprated uppipe
lessening a quick spool

selling that engine.
jgm did mine also, ask what he might think is the issue

my spec is a uk block, but with sti v4 forged pistons
440cc injectors
esl live map board
uk early classic heads
uprated uppipe
td05 16g
welbro pump
front mount

 

+1 for the gaps mate. Had exactly the same problem with mine - regapped the plugs, been fine for 18 months now.

 

James : Before you do anything else I suggest you gap the plugs down to .65mm and I expect your problem will disappear. Let us know mate.

 

what plug gaps set to as said.

coilpacks that hot would perhaps suggest ground issue??

Simon

 

Just going to repeat what the others have said, are the coilpacks new? Gap the plugs to .65mm. Is the bhp a typo seems low for an 18g, where was it from?

Mappers map they dont prep the car for the remap, although as i personally know Simon he will bend over backwords to sort out any issues. Whilst mapping on a GB for me he worked on a car for over 5 hours so it could be mapped at no extra cost.

How are you running V5 heads on a V1 car, what inlet manifold are you using? Who did the rebuild?

 

bhp low due to the misfire.. I couldn't run anymore boost due to the spark misfire.

Simon

 

I shouldnt have asked, knew there would be a reason but thought maybe a JAW had been used

 

no turbo seemed good tbh

 

cheers for the replys guys right heres a list of what i have done to try and eliminate factors.

new plugs regapped to 0.65
compression test = good
engine loom and coil pack wires =14v
earths taken off, cleaned and put back
have checked coil packs with a spare two i had before but new set are on order to eliminate?
cosworth headgaskets are fine
also knock has gone up to a max of 64 now?
checked for boost leaks
dont really know what else to try after coil packs are def eliminated?

james

 

You need 4new packs, swapping 2out wont work.
High knock due to misfire, you will damage the engine driving it on boost with a misfire

 

just a quick one, 7bs should be set to 0.7

 

Yes if you have done everything above you need 4 new coil packs as Simon has already told you....... or a friend to allow you to swap his coil packs on to your vehicle assuming his car has no issues.

 

ok will leave it parked up till i get coil packs on tue/wed then will go from there. will keep you posted thanks guys.

 

just to recap.. it is missing just on boost yes?

 

no not really it misses if you hold the revs at 1500 for instance and just staying at the same speed not on boost feels a bit jerky like it doesnt sustain a smooth cruising speed and obviously pulls back on boost (not smooth)

james

 

so could be a completely failed coilpack or some connection etc.. it shouldn't do that if it is just normal coilpack failure.. it should only misfire on boost as it was earlier this week.

Simon

 

mine used to play uplike that, it ended up being the throttle position senser
after i changed it, i had to set it up. but the revs were fine after

another thing to check, crank senser & cam senser

 

cool will check them tomorrow how do i set up the tps?

 

i did find a post on another site
but it works perfect, you need an oms tester

attatch to 2 of the contacts, it will go to '0' when its in the right position
i'll try and find it as i kept it on a disk a good couple of years back

 

Hope your cars get sorted soon mate.

 

right update

new coil packs are in and no different?
crank angle sensor is ok
cam angle sensor is ok
earths ok
loom ok
compression ok
plugs been gapped and ok
no boost leaks
am really stuck now as im spending money that i dont have to any other ideas

still need to check tps but not sure how to yet ?

also how do i tell if its knackered?

 

tps looked fine last week.

am at dyno again thursday if you want me to take a look

 

thanks for the offer simon but am rammed at work at the mo will have to book it in if cant get it sorted.

1 thing i found out today and am not sure bout which hopefully some one can help is that i have power going to the injectors but no earth ? and also exactly the same with the coil packs? is this right as the other wire that goes to the injector and coil pack is a signal wire? if so where do they get thier earths from? do they need earths? i can only pressume that the coil packs get thier earth from the spark plug? also took the spark plugs out again today and they looklike its been running rich and struggles to start exactly like its not a strong enough spark but just need to no this is an earthing problem or how its supposed to be? do i need a new engine loom?

any help would be great as i am no electrician lol

james

 

thanks for looking at the car yesturday simon. have tried the injectors and they all seem perfect. what i have noticed is that i get a tapping which sounds like its from in the head on the passenger side it did it slightly on the way up to you but louder on the way home and today was quite loud as if its getting worse, any ideas?
thanks for the help aswell everyone else if you have any other input it would be much appreciated

james