Ignition or fuel fault

[Action Man]

Hi guys ... found this place and I guess you may be able to help out..

I run a 91 Hilux pickup with a 3.5 V8 out of an 89 Range Rover .... bit of an old motor but works well .... I fitted a new Edelbrock inlet manifold and a new 4 barrel Holley carb ( vac secondaries) .... new Pop Brown headers and a set of handmade stainless 8-to-8 pipes ( 4 each side - Mad Max style)

Anyhow , ive run it all year up and down the country and not had a problem ...errr till now .... Suddenly wouldn't run properly underpower ... then would stall , then would be ok , now it'll start and tick over fine and rev up a bit... but hold it on a steady throttle and it backfires and then dies..

I've rechecked all the usual stuff and all seems well .... But I'll be going through it all again over winter


Now I've been told that Holly carbs can go way out of sync on the front and rear floats and cause these symtoms??? ( I never had a prob with this set up for 7 years in a Cobra !?!?) ... It sounds like ignition faults but feels like fuel starvation ( I run a new carter pump and it pump just fine )

Anyhow ....any sugesstions ??

I want to sort it out before I pull the motor , cos I'm gettting a new eng for Christmas ( I hope ) and this one can move on but I'm not gonna sell it on if it's got a terminal problem..

it sounds fine http://uk.youtube.com/watch?v=wVHQsSaf0fM

[Paul B]

Water in the fuel?

Does it look like you have fat healthy sparks?

What sort of ignition system are you running?

[RoverP6B]

Putting a good dose of methylated spirits in the petrol tank will remove the water, if there is any. If not, it won't do any harm.

Ron.

[Action Man]

Cheers guys , but I doubt it's water .... looks clean as it pumps through the filter ... and I only ever use BP fuel , and never had a problem in the past 30years with it ... but I'll rig up some fuel from my bike and have another go ..... thing is the eng fires up sweet and ticks over nice .... sparks look healthy ... but I am gonna try a new set of leads and distributor cap ( but they are only a year old so should be OK)...

Ign is the std stuff , nowt special.... but all new wires !?!?!

I am strugling to fix it

However I see British American Engines to a plug-n-play eng kit and even when I get this one sorted it's still an old lump ... a nice new rebuilt motor is rather apealing .....

[Ian Anderson]

Is it a relatively new Holly?

If so open the top and have a look inside the float chambers - been a load of recent ones that have coroded badly, had coatings . peal off and block all sorts of orifaces.

The production had gone to China and the QC was not good

Their most recent production seems to be getting better again

Ian

[Action Man]

Yup the Holly is / well was Brand new .... fitted it last winter when I did teh eng swap .... I've had the carb in bits and it's perfect inside , errr just like I'd expect it to be ... however I'm being told that Holly carbs do go out of ballance and the floats go out of sync .... errrr cept they work like bike ones so I don't see how .... Anyhow I'm gonna strip it all again ... I'm begining to think it's just a lot of little faults in the wireing and HT leads that are causing it .... So a full strip out of teh electrics may well sort it out ....

However a nice crate engine from British American is very tempting .. Anyone used them before ??

[sidecar]

However a nice crate engine from British American is very tempting .. Anyone used them before ??

Loads nof cobra reps are power by BAE engines, they seem like a good company to do business with.

My money is on a carb issue, bunged up main jets or something similar!

Pete

[wynterburne]

Could it be condenser? (Apologies if you have electronic ignition). Had a similar problem on my engine which I assumed was fuel related and stripped the whole lot out, turned out to be a condenser that failed due to bad earth.

Regards

Richard