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355 chev - not idling giving me the shits


escortwags

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Ok so heres a small novel of my dramas....



 

355 chev

600 slayer carb

10:1 comp
Comp Cams Camshaft ,Intake lift .507 Duration 284,Exhaust Lift .510 Duration 296,Double Roller Timing Chain Anti Pump-up Lifters 
alloy heads
big valves etc
heaps of other crap done fresh crate motor

2500 stall

(can give full spec list if it helps)

 

CAR WAS RUNNING MINT

 

- drove round auckland about 100kms after cert and all was well

- skids it likes, high RPM it like

- drove up north 350kms and never missed a beat, never had to tap gas to start it etc. 

 

- parked car for 3 days in a shed

 

****

 

- returned to start the car like normal was fine for 10 seconds then lost idle and started puffing black smoke and running on what sounded like no more than 7 WTF

- half pulled carb down (which is 400kms old) and nothing in there

- pulled plugs (were dirty) cleaned with carb cleaner
- reassembled and it runs again, slighty ruffer than before but still happy

 

****

 

- drive another 100+kms in between little towns back and forth

 

****

 

- 2 days later go to start car NO IDLE what so ever, still has balls above 2 grand but anything less it hates

 

- check leads, one is a bit burnt, replaced with a full set of brand new leads and new NGK cheap plugs

 

- car is happy once again, although still not 100%

100+kms driven

 

****

 

- 1 day later

 

- start car no pedal needed drive for about 5kms, looses idle again, going down hill at 50km/ph car is trying to die, get to bottom of hill and its sounding like shit, need to floor it and pump the pedal like shit to get it started. Pre-stage my way onto car ferry.

 

****

 

- pulled plugs looked at them and put them back in, car happy for about 5mins, then back to shit

 

****

 

- change to $$$ NGK platinum plugs, recheck leads (O.K) check inside dizzy (O.K) car is happy, drive 200+kms without a hitch, after that car starts loosing idle again and hates anything under 1,500rpm, doesn't matter as Im going 100 and still has balls although backfire type sounds on decal are wierd

 

- also removed fuel filter which was clean as a whistle

 

****

 

PRESENT DAY

 

car will start with no pumps and idle off the high speed idle, as soon as choke goes it looses idle and needs foot to the floor pedal pumping to start. sounds like shit below 2000, runs mint up top. Noticed front fuel bowl low but that shouldn't effect idle?

 

WHAT AM I MISSING??? / KNOB
, must get running right for Kumeu

 

fanx
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dont have a wideband (SAD)

- was meant to be getting a tune but Magnum is way to busy, but super keen to get to Kumeu without looking like an idiot

 

- running a china 65,000 Volt HEI thing, that looks/is brand new, but im starting to blame it

 

- going to re-adjust float heights tonight, all vacuum ports are plugged bar the signal for the tranny and cant hear any obvious ones. Will try the carb cleaner method to see if something sneaky is happening I guess

 

- will re-tourqe all manifold bolts but they have always been tight so god knows

 

BOX OF BEER TO WHOEVER LEADS ME TO THE FIXABLE ISSUE  :)

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old plugs were dirty (black), but i've seen 20 x worse that still ran a car fine

new plugs are still cleanish

 

- 3 bond grey any good to use to seal between carb and manifold? (only has paper gasket at the mo)

 

- when you free rev it, it sounds like it tries to hit idle for a split second then goes PUTTER PUTTER PUTTER DEAD. (setting idle at 1000rpm)

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Are you running one of those chinese knock off "MSD" units? (Pro-Comp or similar)

 

If so then THROW AWAY and start again. They are complete and utter junk. I had a distributor of theirs and the trigger ring was sitting on a 30 degree angle on the shaft.

Also have seen the inside of one of their "MSD" boxes and it was thin wires connecting together some capacitors that looked like they had spent their life in a nuclear waste pile under the sea.

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ahhhhh yeh one of those units, me thinks. We stripped it down a week or so ago hung over and it seemed oke (solid wires, connecters proper electrical goo crap where it should be, nice and clean and new looking insides)

 

so if it aint a vacuum leak you reckon its that piece of shit playing up? best place to buy a decent replacement?

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As your lawyer I recommend you follow this course of action...

  • Set carb float heights
  • Test for vacuum leaks
  • Hunt down a proven dizzy you can borrow
  • Acquire your own proven dizzy at swapmeet
  • Fit your own proven dizzy
  • Aquire Dre
  • Fuck bitches
  • Smoke trees
  • Profit
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Shall do the above although Dre is already next on the cars playlist

 

EDIT

 

yeh, but his one is just a new china poo one as well hahahaha.

Not even sure If I could get the dizzy out easily without moving the whole motor forward

 

this just looks like a knock off as well? and poo voltage

 

http://www.trademe.co.nz/motors/car-parts-accessories/chevrolet/engines/auction-682925014.htm

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Just a thought, what type of tach are you running? i've had a autometer go bad on me effectively sucking all the juice away from the primary of the coil making the car run shit due to a average spark. took tach out for something else unrelated and car magically ran sweet.

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from what you described in your first post, it seems to be running rich? which is making it run shitty when its warm

 

too much fuel pressure? although float levels would be high if that was the case

 

Timing correct? not retarded at idle?

 

Power valve wrong or damaged? should have blow out protection being a new carb  

 

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Just found a lose manifold bolt and others needed a tweak, going to reset the floats now

Car doesn't have to be warm for it to go wierd choke is set to only run for 30 seconds (electric)

Running a bunch of the small old looking but new autometer gauges

Car running is putting out 14v

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Oh and vacuum advance is not hooked up and never has been
*should I jam this on?

Ok so no vacumm leak I just timed my rag on the carb wrong
I pulled the wires off the HEI put them back on, it started and took a 3 minute video of it idling happy as
In gear the revs drop down to 450-500 but that's a tune issue (might need more tranny fluid also)

Now starts off the key without touching the gas like it used to

Gave it some revs then a small one and a ball of fire from the carb burnt my eyelashes off.
So is it a timing issue then?

I'm chasing a ghost

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