Pinto Running Rough

[steve_wilson]

hi all

 

i've got my engine running but it seems to be running rough and as though it's only on 3 cylinders.

i'll get a video up later to help diagnose.

 

it's got a piper 285 (i think) cam with vernier cam pulley and on a points ignition system. the vernier cam pulley is set to 0 degrees, is this ok or does is need advancing/retarding?

 

it's got all new plugs and leads and has a good spark on all cylinders.

 

Any suggestions? i know i've been fairly vauge but if theres anything else you need to know please let me know.

 

Thanks, Steve

[Guest julien]

hi all

 

i've got my engine running but it seems to be running rough and as though it's only on 3 cylinders.

i'll get a video up later to help diagnose.

 

it's got a piper 285 (i think) cam with vernier cam pulley and on a points ignition system. the vernier cam pulley is set to 0 degrees, is this ok or does is need advancing/retarding?

 

it's got all new plugs and leads and has a good spark on all cylinders.

 

Any suggestions? i know i've been fairly vauge but if theres anything else you need to know please let me know.

 

Thanks, Steve

....steve are u running a carb or injection??

[steve_wilson]

its on a carb, the standard weber carb

[Guest MarkB]

HAVE YOU GOT THE PIPE FROM MANIFOLD TO SERVO CONNECTED? IF NOT NUMBER 4 WILL MISS LIKE A "GOODUN"

 

SORRY FOR THE CAPS, USING ACCOUNTING COMPUTER... NO LOWER CASE AVAILABLE

[steve_wilson]

yeah the manifold to servo vac pipe is connected as is the one from the carb to the distributor

 

here's a video of how it sounds

 

 

it might just be me, but i swear it doesnt sound right!

[steve_wilson]

can maybe hear it better here

 

[Guest old_timbo]

Steve,

 

You've got some fine tuning to do but the Piper 285 is quite a lumpy cam at low revs and when cold. Comes good when you give it the beans! The second of your videos sounds similar to my 2.0 Pinto with the same cam. Mine sounds a bit crisper as it has a RH 4-1 manifold and has been on a rolling road for a carb / timing set-up. I carried out the Dizzy advance mod on the NW RH owners site and get full advance at about 2500 rpm. 32 degrees of advance gave max power at about 6000 rpm. At tick over with no vacuum to the dizzy this was 8 degrees.

 

Tim

[steve_wilson]

ah well its good to know theres nothing major wrong, just fettling

 

i'll just get it to a reasonable state of running for now and get it properly set up after the iva i think!

 

many thanks for everyones input, and if anyone else has any thoughts please let me know!

[Peter Bell]

Steve, you will need to set up the cam timing otherwise you may as well left the original pulley on it. I think the instructions will be on the Piper site, but you will need a dial gauge and a timing purtractor disc thingy. Mine is about 5° or so off a nominal 0 as far as I can remember. You will have to advance the ignition timing too, mine is about 14° at tickover with no advance. Try turning the dizzy at tick over you will probably find the engine speeds up and smooths out. If it pinks under load back it off a little.

[Longboarder]

You don't say if you had the head skimmed. This will alter cam timing. Also Piper themselves say don't trust the keyways in the cam and vernier to give the correct cam timing. Thats the purpose of the vernier. Use a dial gauge and protractor to set the cam timing to Pipers spec as Peter says.

 

Nigel

[steve_wilson]

i'm not sure if the head has been skimmed nigel. i didnt build the engine so not entriely sure of specs, although i am sure it has a fast cam.

i'll have a look on the piper website and follow their instructions.

 

if i do a compression test could you tell if i've had the head skimmed?

 

Thanks again

[Longboarder]

Probably not. Long duration cam may even give an apparent drop in compression at cranking speeds. If the head has been skimmed or not the procedure for cam timing is still the same.

 

Nigel

[Guest trackerjack]

Different engine I know but strange how similar they are in some respects (bore/stroke).

My Sprint engine is meant to be set at 11 btdc but it likes 16 btdc and it too runs a Piper 270.

I have yet to fit my Kent RL2 in my Hood but expect to play about with it before it comes good.

The Sprint has been honed over a number of years and I have only just started with the Pinto.

[steve_wilson]

i've fitted a spare carb i had kicking around and it seems to idle a lot better. still have some teething problems with it, but i'll try get them sorted this weekend.

 

many thanks to everyone so far. will report back with my findings!

[steve_wilson]

had another tinker with this today and still doesnt seem right.

 

im sorry for the non technical description but i've never timed an engine before...

i got a timing strobe off ebay and timed it up using the mark on the crank pulley, i've set it to 0degrees pretty much dead on.

 

the car won't idle anymore it needs constant pressure on the pedal to make it keep going, and it also seems to backfire at what i'd guess to be 2000rpm (no rev counter yet) but then seems fine at roughly 4000rpm.

 

i've got all the vaccum pipes connected up and it's a got a fast cam with a vernier pulley which is also set to 0degrees.

 

 

i might have missed something obvious but as im new to this im not 100% confident with it.

 

any ideas?

 

Thanks, steve