P73 Vs. PCT Pistons

[ramboteamjon]

whats up with your rambo? not good news again?

Yea got bad news again. A month ago it was on the dyno at henrys and it ran 177bhp remember, well this time it ran a 173bhp with the exhaust sorted, changed oil, cold air feed to teg air box, new plugs and leads and dizzy cap and rotor arm! total mystery! the torque figure is still at 115 which is about right.

Compression is 225 on all 4 cylinders
timing is ok
henry even tired a different p28 ecu with a B16B base map on it that guranteses over 190bhp with a header and exhaust. So when my car went on the dyno with that ecu my car just rejecting the extra fuel and spat it out the back and still made 173bhp! WTF!!! obviously something is not right, full throttle issue??
lambda is fine
plugs are fine
henry said it aint burning oil at all and no blue smoke on vtec

I showed my graphs to Andy Forrest (subaru tuner) and he said becuase it is running so rich up top (11.2) it must be something restricting the air flow?! Throttle body maybe?
just had the IACV cleaned so not that.

Few folk have said valves not seated properly or worn bores? but would that not cause my compression to **** up?

Henry and pimpin reckon it could be ek4 cams or something like them that have been fitted by a previous owner and thats whats holding the power back? they said it could be a re-stamped block but I checked my block compared to my mates ek4 and ek9 blocks and its defo the B16B as the block sits higher than the gearbox.

I contacted the person I bought the car off and he assures me he never touched anything internal on the engine and I believe him as he was a very genuine guy and we still keep in touch after 2 years. dont know who brought the car and when into the country and I obviously have no history of what happenend to it in Japan as I got no papers whatsoever with the car so god knos?

Anyone got any ideas? clue? please?

I am booked back in with Henry in Nov and he wants to take the head off and have a look to see if there is anything suspicious so fingers crossed! the thing is it drives perfect and pulls great becuase of the final drive! imagine if it was running proper power with a tune, it would be amazing!

total head scratcher mate, henry will get to the bottom of it though

Cheers man I hope so!

 

[Championship White]

Weird, I hope this Henry chap fixes everything up for you Rambo. I saw a B16b with that problem but worse so that it was totally strangling itself higher up the revs and a loss of power everywhere else, it was something to do with the timing in the end, might have even been a faulty cam gear issue too.

 

[olly ek9]

have you got a tourque curve graph for teh said motor? as champ white says sounds like cam timing too advanced , this woudl be highlighted by a wedge of trouque low down in teh graph,, lets have a butchers

 

[ramboteamjon]

Weird, I hope this Henry chap fixes everything up for you Rambo. I saw a B16b with that problem but worse so that it was totally strangling itself higher up the revs and a loss of power everywhere else, it was something to do with the timing in the end, might have even been a faulty cam gear issue too.

Hey man I hope so too and Henry is defo the man to fix it! He has done well for alot of other people so fingers crossed!

have you got a tourque curve graph for teh said motor? as champ white says sounds like cam timing too advanced , this woudl be highlighted by a wedge of trouque low down in teh graph,, lets have a butchers

Yea I have a couple of graphs mate, I will post them up when I am home from work no bother. Hopefully you can help as the graph means nothing to me! lol cheers

 

[pimpinblackcivic]

thought about that olly but we are talking stock timing, with stock cams and cam gears henrys base map runs about 8 degrees advanced so we should have seen an improvement when he put that on, but it was worse.....running mega rich in vtec with a lot of fuel smoke.

there is something restricting it from flowing enough and combusting enough air hence why we think it may be cam related, a really bad valve seal in theory could cause it but then would have shown up in the compression/leakdown test...the numbers would also suggest the cylinders are in good shape

 

[Vtec6000]

8 degrees timing over stock ctr map? So you have high 30's timing at WOT? That's a lot of timing especially with your compression you sure it's not knocking it's arse off? Even with reducing injector ms in fuel map can he not get the AFR's leaner?

Have you pulled the rocker cover off to inspect cam lobes and rocker arms? Does change over to vtec sound strong? No oil pressure problems?

 

[ramboteamjon]

thought about that olly but we are talking stock timing, with stock cams and cam gears henrys base map runs about 8 degrees advanced so we should have seen an improvement when he put that on, but it was worse.....running mega rich in vtec with a lot of fuel smoke.

there is something restricting it from flowing enough and combusting enough air hence why we think it may be cam related, a really bad valve seal in theory could cause it but then would have shown up in the compression/leakdown test...the numbers would also suggest the cylinders are in good shape

yeah all you have said makes sense and could point towards the problem but with my compression being good it just dont make sense!!

8 degrees timing over stock ctr map? So you have high 30's timing at WOT? That's a lot of timing especially with your compression you sure it's not knocking it's arse off? Even with reducing injector ms in fuel map can he not get the AFR's leaner?

Have you pulled the rocker cover off to inspect cam lobes and rocker arms? Does change over to vtec sound strong? No oil pressure problems?

not sure about your 1st 2 questions so pimpin can answer them sorry. its defo not knocking its arse off as it runs/drive perfect just its down on a bit power. Henry doesnt want to map it yet as its not even running stock power and I should be running atleast with my mods!

Nah nothing has been pulled apart yet, the car is going back to henry in Nov so he will open it up then and have a look. I was thinking worn lobes and rocker arms but I dont know, only having a look will tell and we could guess all day long!

Vtec change over sound is extremely strong and always 6.2k revs on the button and right up to 8 odd k so no problems there! not sure about oil pressure, henry will have to check that.

I will get my graphs up today.

Just want to get to the bottom off this asap!

 

[eternal blue 2000]

thats a bummer mate.
At least it still drives thou and our henry should sort it in time.

 

[ramboteamjon]

thats a bummer mate.
At least it still drives thou and our henry should sort it in time.

a kno man!
exaclty, to me it drives perfect and pulls well but I still wanting it running at full power!

2nd graph as promised! torque is top blue line.

 

[pimpinblackcivic]

8 degrees timing over stock ctr map? So you have high 30's timing at WOT? That's a lot of timing especially with your compression you sure it's not knocking it's arse off? Even with reducing injector ms in fuel map can he not get the AFR's leaner?

Have you pulled the rocker cover off to inspect cam lobes and rocker arms? Does change over to vtec sound strong? No oil pressure problems?

pass mate, i'm sure he said 8 degrees over a stock map but i might be wrong, not knocking under load either....only reason he tried that map was so see if playing about with the fuelling/ignition would improve it which it didnt....yes he could lean it out and get it behaving itself, but point being is its down a fair bit on power from where it should be and thats the part needing investigated first before he bothers mapping it

 

[ramboteamjon]

yea he defo said 8 degrees over a stock map but as you said he only used that ecu to see if it was my ecu that was possibly causing the problem! in the end it wasnt and looks like something internal which is a bit **** as it will have to be opened up! Henry will see it right tho and I'm looking forward to it!
Yea I see it the same as henry, I would rather the problem was sorted first and my engine was running closer if not a bit higher than stock power then he can take it from there and map it!
I am still swaying towards a problem with the cams but I'm no expert!

 

[olly ek9]

cams or cam timing gotta be...

 

[Championship White]

cams or cam timing gotta be...

I'm with Olly, there isn't anything else which could effect all the cyclinders in such a way. On the engine I was on about, we went through every single possibility, even the ones we were sure it wouldn't be and it turned out to be a mystery timing issue.

 

[ramboteamjon]

cams or cam timing gotta be...

nice one cheers, can this be fixed easily tho?

I'm with Olly, there isn't anything else which could effect all the cyclinders in such a way. On the engine I was on about, we went through every single possibility, even the ones we were sure it wouldn't be and it turned out to be a mystery timing issue.

that is exaclty what henry was gona do, check everything but if it is a timing issue can it be fixed easily? how did you fix the problem you encountered if you dont me asking?

 

[Gorbash12346]

timing is a pretty easy fix. but if it's the cams i'ts a little more involved. no biggy for someone who knows the b-series engines well. might be worth getting yourself a new rocker cover gasket and spark plug tube seals plus new camshaft oil seals in case the cams do need to come out. that way you shouldn't need to worry about leaks later on

 

[Championship White]

A long story Rambo and to be honest, I'm still not 100% on what the fault was, I still can't for the life of me see how the cam gears could have been faulty and caused the problem which is what I've put it down to in the end. It was all aftermarket parts, mainly Skunk2, in the head of the engine so I wouldn't want to send you down the wrong track with your problem as the trouble all started with the new cam gears and installer error by a mechanic (didn't realise Tuner series had a mark for every 2 degrees instead of for every 1 as the Pro series had) for the engine in question.

It was a bloody headache, stumped quite a few experienced engine tuners.

 

[ramboteamjon]

timing is a pretty easy fix. but if it's the cams i'ts a little more involved. no biggy for someone who knows the b-series engines well. might be worth getting yourself a new rocker cover gasket and spark plug tube seals plus new camshaft oil seals in case the cams do need to come out. that way you shouldn't need to worry about leaks later on

Sound mate, yea am sure Henry would be able to do it no bother! Good shout mate I will do, cheers for the heads up!

A long story Rambo and to be honest, I'm still not 100% on what the fault was, I still can't for the life of me see how the cam gears could have been faulty and caused the problem which is what I've put it down to in the end. It was all aftermarket parts, mainly Skunk2, in the head of the engine so I wouldn't want to send you down the wrong track with your problem as the trouble all started with the new cam gears and installer error by a mechanic (didn't realise Tuner series had a mark for every 2 degrees instead of for every 1 as the Pro series had) for the engine in question.

It was a bloody headache, stumped quite a few experienced engine tuners.

No worries at all, my internals are all stock and have never been touched as far as my knowledge of the history of the car goes anyway! Only time will tell once Henry takes the rocker cover and pulleys off!
Hopefully its a simple fix and al be good to go in no time! thanks again!

 

[Rich777]

Take the rocker cover and top cambelt cover peice (2x 10mm bolts on the far right) off, pull the spark, rotate the crank pulley around so the notch on its own on the pulley is inline with the groove on the lower cambelt cover. When you have done that take a look at your cam gears and see if the marks line up.

 

[ramboteamjon]

Take the rocker cover and top cambelt cover peice (2x 10mm bolts on the far right) off, pull the spark, rotate the crank pulley around so the notch on its own on the pulley is inline with the groove on the lower cambelt cover. When you have done that take a look at your cam gears and see if the marks line up.

thanks for the info mate, I would love to do as you say but I dont have the know how or confidence in myself to do that sort of work! I will leave it to henry and hopefully he finds the problem! thanks again!

 

[ramboteamjon]

Me and Cal just had a thought, could it be that the pistons in my engine are P73 ones or even B16a pistons and compression is not right so thats why am down on power? could it also be worn pistons??