19 replies to this topic

[notthatrusty]

hello all.
i have the turbo engine in of a fashion and am now on with getting the bleeder running.
i have the fuel pump and regulator mounted and piped in and have carb turbo etc all plumbed in to the fuel system.

anyway the engine will start on choke and tick over (all be it 1200rpm) but will die as soon as throttle is applied.

i noticed fuel coming from inlet manifold and dripping down the back of the engine block so suspected a poor mating inlet/exhaust manifold and this was causing the engine to suck in air hence cutting out when throttle applied.

tried blipping throttle and basically getting excited to hear it finally running then lots of smoke spewing out of the exhaust side of the turbo (no actual exhaust pipe fitted yet)

i took off the inlet manifold to check the gasket ,which is not good, and also took out the spark plugs and noticed a lot of fuel on the piston tops.

so basically was wondering if the poorly mating inlet manifold could cause the carb to pump high amount of fuel into the chambers or if there is any other reason why there seems to be so much fuel in there.

p.s i think all the smoke out of the exhaust side of the turbo must have been the fuel build up im the chambers getting pushed through the exhuast valves and smoking on the hot turbo exhaust casting. hopefully. lucky it wasnt hot enough to ignite it as only ran briefly.

cheers.
mark

[Turbo Phil]

Sounds like it's flooding to me. Have you rebuilt the carb ? Most likely the needle valve is worn or some dirt is on it or the seat, allowing fuel to pass.

[notthatrusty]

cheers for the response phil. no i havnt rebuilt the carb.

the history is: the engine is some 20 odd years old but has only done 3k and the gearbox is brand new.
i aquired through an old timer from a barn as you usaually do with these things and in my nievaty was hoping to get it in the engine bay and running without doing to much messing around as i have found out was a serious misjudgment on my part.

would this sticking needle cause the inlet manifold to leak from the pooling of fuel, also might be worth a mention that for some unknown reason the cables i used to sling the engine whilst craning it in decided to snap and thus the engine dropped lightly into the engine bay connecting ever so briscly with the carb bottom hitting the scuttle panel. haha. yeah i laughed too.

i have been up ur way before asking advice on putting this engine in and that was some months ago and am still messing around. how much would you be looking at for you to rebuild the carb for me phil.
cheers
mark.

p.s i am getting a bit closer though, at least its in.

[Turbo Nick]

have you set the base fuel pressure at 3.5psi?

next check is to switch ont eh ignition so the pump kicks in and remove the dashpot, if fuel is coming up out of the jet then the valve is stuck open.

[notthatrusty]

cheers bud. no i havnt set the base pressure just bolted the fuel regulator on as it came.
if this is set too high could it flood the engine. i ws assuming the extra fuel would just go back down the return line? think i need to get me a little gauge and check this out.

[Ethel]

The pump circulates fuel constantly, that's why there is a return line. The regulator reduces the pressure in the carb outlet to 3 or so psi above the boost pressure because boost pressure is also present in the float chamber and carb.

[notthatrusty]

thanks ethel. so i take it i should connect a pressure guage to the outlet of the pressure regulator and then adjust the regulator to give 3 or so psi.

[Ethel]

That's correct, as the pump runs constantly you should get a fair idea just by removing the dashpot and piston, as suggested above. If you have a fuel pressure gauge you could plumb it in on a tee off the carb fuel line and watch to see it keeps a few psi ahead of the boost gauge, though a wide band O2 gauge is better for keeping track of fuelling.

[notthatrusty]

That's correct, as the pump runs constantly you should get a fair idea just by removing the dashpot and piston, as suggested above. If you have a fuel pressure gauge you could plumb it in on a tee off the carb fuel line and watch to see it keeps a few psi ahead of the boost gauge, though a wide band O2 gauge is better for keeping track of fuelling.

what sort of pressures are we looking at here, what i mean is what would be the best guage to put in the fuel line from regulator to carb. just a 1 bar or 15 psi guage to set 3.5 psi base pressure or a 100psi guage to monitor running on boost?
cheers hope you know what i mean.

[Turbo Nick]

no need to monitor it while driving unless you're trouble shooting on boost problems really.

best bet is to take off the fuel pipe at the carb, stick a gauge in it and adjust the pressure to 3 or 4 psi. no need to have the engine running or bother with t pieces etc just ignition on will do.

then to check if the float valve is ok connect it back up and switch the ignition on with the dash pot off, if fuels coming up out the jet then this needs investigating too.

although if its not been rebuilt then doing so is a very good move, i had no end of trouble with choke seals causing mine to flood until i rebuilt it.

Edited by bud666, 07 February 2009 - 10:29 PM.

[notthatrusty]

no need to monitor it while driving unless you're trouble shooting on boost problems really.

best bet is to take off the fuel pipe at the carb, stick a gauge in it and adjust the pressure to 3 or 4 psi. no need to have the engine running or bother with t pieces etc just ignition on will do.

then to check if the float valve is ok connect it back up and switch the ignition on with the dash pot off, if fuels coming up out the jet then this needs investigating too.

although if its not been rebuilt then doing so is a very good move, i had no end of trouble with choke seals causing mine to flood until i rebuilt it.

cheers bud i appreciate the advice.
i made the error of assuming that the engine and all its components were good as it the engine , turbo, carb etc has only done 3.5k miles and gearbox is brand new. seams that it sitting idle for 20 years may have had some affect. doh. im gonna ebay myself a nice fuel pressure guage now. thanks again all for helping me out.
hope to be on the road this year.

[Turbo Nick]

just nip to halfords or your local motor factors and get a gunsons lo-gauge, around £15 when i got mine.

[notthatrusty]

hello again.
i have fitted a new exhaust/inlet gasket now so no leaks in that department. have also searched through the forums and trawled the net and have disconnected the fuel inlet and blocked off fuel out from regulator and fuel into carb and turned engine over to burn up the fuel in the float bowl. then reconnected to get a surge of fuel through the clean out any suspected dirt, as i read this somewhere. i also have two inline filters in the fuel system and all the fuel lines, regulator and pump are brand new.

i can start the engine with choke on and revs up of a fashion useing throttle with the choke on but if i even look at the choke lever it stops.

the dissy has been out whilst i was cleaning the block so the timing has therefore been upset. i have set the timing adopting the static timing method using number one piston and turning the dissy in its hole to the specified degrees btdc. would this cause the engine to only run on choke as i was under the impression that it would do to drive to a garage to get the timing strobe on it for adjustments?

i believe that all is correct with regards to the needle as the engine, turbo, carb are all out of the same car and everything is matched as it came out of the factory so it hasnt got any racy cams or wrong needle from another engine setup or anything of this nature. also the whole engine setup has only done 3.5k in its life so i wouldnt expect any worn parts but it has not been in a car since the mid 80's. it has been turned over periodically though.

one point i have just realised is that the hole in the inlet manifold, that would have the one way valve in it, i have blocked up using a banjo with a bolt through to block the holes and this may not be completely air tight. could this be my nemesis?

[miRon]

have you set the base fuel pressure at 3.5psi?

next check is to switch ont eh ignition so the pump kicks in and remove the dashpot, if fuel is coming up out of the jet then the valve is stuck open.

or your return pipe is blocked....

i had this problem yesterday...lol

[Ethel]

Have you seen any fuel in the main jet? Worth checking the regulator pressure if it's brand new, it might not be set with an SU in mind.