Big Problems - chitty chitty bang bang

[PaulB]

Hi Guys,
I hope one of you can point me in the right direction. Ive had my car on the rollers today and it got 250bhp with 1bar, using a forge boost controller.

The thing is, after taking the car off the rollers and on the road, the car now coughs and splutters its way up the rev range. It idles fine and revs no problems when in neutral, and if you slowly press the accelerator down it drives ok-ish (slowly mind).

As soon as the throttle is flat out the car splutters and misfires its way up the revs, sounding like its running on 3 cylinders. Its had new plugs and leads on which i have changed back but its no different. I have put all the pipework back to standard and its the same, boosting up to 10ish but waving about 8 - 12psi. It is pretty much undrivable other than at low speeds.
Im wondering if its actuator, air leak, coil, anything????

Im gutted, wish id never bothered tryin to mod it now as it ran sweet as a nut before.

Heres the print out......

http://i25.photobucket.com/albums/c57/paulb81/P1020178.jpg

thanks in advance.

 

[SickBoy]

Check your plugs dude may have blown one ... also leads

Lee

 

[Shaun]

Sounds like you may have blown a boost hose off mate.Give your piperun a check over.

 

[Rishi]

You have a very good torque figure for that boost....

Check your Rotor Arm, Dizzy... Also the Plugs and Leads... I know you're repleced the plugs but take them out and see if they all look normal and dry...

Check the Injector Resistor Pack... This can corrode and fail causing incorrect voltage to the injectors and can cause it to lean...


Rishi

 

[PaulB]

Yeah, i have replaced leads and plugs back to the one previous and all is the same. Il give my pipe run a good check over tommorrow, i hope its something cheap and inexpensive.

So by saying all this, does this mean that there is no chance it is the actuator??
Just that the wiggly figure on the printout should be smooth and its all over the shop.....

Anyone have one to borrow and eliminate from my investigations ??!?!?

 

[™ƒũ†ũ®Э●ŤђЦĞĞϊη™]

try pulling out a lead 1 at a time and check for a change in the engine if its a misfire it will cutout when you pull the leads and not change when you found the shitty one

 

[PaulB]

yeah will do,
dont think its too bad on idle, just wen its on load. Could be my coil pack too, just put plugs in and set them at 0.9mm gap, could be too much for the coil. doh !

 

[Fast Guy]

Why did they only rev it to 5100rpm on the rollers? You'll make max power at around 6200rpm and you'd probably have got 275ish like most other people get on 1bar.

Have you tried a fault code check to see if anything comes up?

 

[daz]

end of the day number one if a boost hose had come off it would have blown up by now as it would run unlimited boost. so that rules that out. the black line thats all squigly and all over the place looks like its black hence thats your engine output. looks to me that on that power graph they have not included your boost curve. but anyway paul if you are getting a mis fire under load then that points the finger at the ignition system. i had this problem a while ago where under load the car used to backfire then one day it did it and just died, swapped the coil pack and it was sorted. does the boost hold at 1 bar all the way through the rev range if so then that rules out your actuator. hope all this helps. also paul you want to be gapping your plugs at about 0.7 or 0.6mm, as you may just be blowing the spark out, mine are set at 0.6mm and mine runs fine at 1.2, 1.3 bar

 

[Fast Guy]

end of the day number one if a boost hose had come off it would have blown up by now as it would run unlimited boost. so that rules that out.

Only if the actuator hose had come off/split.

Other boost hoses cause it to run like shite and misfire/pop/bang and generally scare pedestrians to crap:lol:


I deleted the blowing out spark from my reply above as I misread you 0.9mm gap (old age setting in:doh: ) It could be worth closing the gap up abit.

 

[KF79GTIR]

missfire

hi ya mate i had the same prob with mine and cooked a piston because of overboosting make sure your not havin the same problem when your motor is running if you pull the dip stick out a little bit and rev it if you get smoke coming out the dip stick hole you hace melted a piston or a ring check asap as it could save your block and you about 1600 notes

 

[PaulB]

Thanks for all the help fellas.

I have just ordered a new coil pack, think its gonna be that, hard to test tho as it only does it under load (ie full throttle). Ive checked the oil/ water issue. I drove all the way back from the rolling road in scotland and all the temps were fine, and it cruises ok.

Im gonna close the plug gaps down a bit, and hopefully that will sort it and i can get only with enjoying the car again.

 

[PaulB]

YES YES YES, its SORTED.

I fitted me coil pack, cleaned the inside of my dizzy, scraped off the crap, disco`d the battery for a bit and all is well.

Phew, thank god for that, my first (and last? hehe) problem with my R.

Thanks again for the help fellas, im gonna go give it some beans, a nice steady 1bar, champion.
:-D :-D

 

[Fast Guy]

Phew, thank god for that, my first (and last? hehe) problem with my R.

Aww bless, so naive still:lol:

 

[PaulB]

Nah, not naive, just hopeful. Owned a modified French car before this so it cant be any worse than that thing !!