2200 to 3000 rpm stuttering

[Big Nick]

Just had my van set up and rolling roaded, its putting out 76bhp at the rear wheels which is I guess around 100 at the fly wheel about right for my engine spec. However not long after this was done (and after a bit of a thrashing) I have noticed a intermitant stuttering between around 2200 (normally 2500) and 3000 rpm when the engine is under load, it does not happen all the time and seems to be absent at lower and higher rpm, The symptoms are if it is momentarily starved of fuel or spark (we are talking fractions of a second here).

Brief engine spec, 1776, engle 110, Empi style 044's, 009 with ignitor ignition and coil, dual 40 Empi webber rip offs (showing some signs of wear), facet electric fuel pump with regulator valve. Engine cooling is well sorted (Internal and external coolers - with by pass and deep sump) and typical running temps are between 70 and 95 degrees when running at 50 to 60 mph.

Today this only occured after the oil was up to 70 degrees plus (normally when the engine is at its happiest).

Any thoughts (I have checked all the leads and they seem to be located fine).

Thanks in advance

Nick & Zile

 

[Clarkson46]

Personally, there are 2 issues at stake here. EMPI and 009, both are recipes for disaster. IMHO. :mrgreen:

 

[Guest]

Personally, there are 2 issues at stake here. EMPI and 009, both are recipes for disaster. IMHO. :mrgreen:

id definitely aggree, ditch the 009 for a vaccuum advance, the carbs might be a bit more pricey to change

 

[Joval]

009 should be fine at that RPM, getting there is the problem..

I reckon it's a carb issue - that's about the RPM you change from idle to main/correction jets

 

[easy]

Agree with all above :wink: change the 009 to vac advance first then if this is still happening have a good look over the carbs and change if possible :mrgreen:

 

[Slammed]

I reckon it's a carb issue - that's about the RPM you change from idle to main/correction jets

Just reread it... What heads are you running? Inlets and outlets? :?:

 

[Big Nick]

I don't have the exact spec of the engine as it came with the van but it is a Remtech unit and the the inlets and outlets are most probably 40/ 35.5. I know the carbs are most probably an issue but I did not have this stuttering before the rolling road or for a few days afterwards, Previously it was only running 10 degrees of advance and was drinking fuel (lots unburnt) now it is running about 20 but on the rolling road was happier at nearer 40 at lower RPM but pinking at nearer max throttle has anyone tried a 123 dizzy as these apparently have 17 programmable advance curves? P.S. I own a set of low mileage 40 DRLA's with X bar linkage but I am loath to take them off our bug!

Regards

Nick & Zile

 

[Big Nick]

Intermitent stuttering getting worse but only after the oil gets up to 70 degrees, previously the van didn't run very well at lower temps now it aint running so good (2200 to 3000 rpm) when at normal op temps, you just cant win! :wink:

Thanks for everyones input and I am sure your right that the carbs. dizzy aren't helping matters.

If I was to go back to a vacuum advance dizzy, where would be the take off for the vac?

Cheers
Nick & Zile

 

[Guest]

you can take it off the carb manifolds by drill and tapping one side. Some people also balance them with tubing and a t-bar but its alot more work.