The V8 Owners Forum -

Think you would be able to catch it on the throttle even if the stepper was stuck shut.

Have you checked the TPS, also what fuel pressure are you running.

Did everything calibrate ok using VEMs?

As mentioned above Green Tune resistor is for Non Cat, should be 470 ohm

Checked my stepper motor, its fully open when cranking and cycles closed/open when I stop cranking.

Tune resistor is the green wire type, checked and is 470 ohms

Fuel pressure is set at around 34psi

Checked TPS and seems to be ok

Also changed the coolant temp sensor.


Now the car still smells of fuel, BUT it has begun to "splutter" a bit when cranking as if trying to fire, whereas before it didnt do anything.

Will have to see what the new plugs do tomorrow, fingers crossed

well, finally got the new plugs today, noticed they were longer than the ones i had fitted.

turns out from day one of putting the engine in it had the short pre-1976 plugs fitted!!! (ok, my mistake lol), still it ran quite well with the carb on it hehe


she fired first turn of the key with the new plugs so its all good


Thanks for everyones help/suggestions!!!

Stuball

Ok, engine now starts on the button, no problems, warms up fine idle is around 900ish.

Couple of "issues" though.

1. When left idling and warm the revs occasinally dip to about 700 and come back up again, dont know why this is.

2. Light throttle/cruising the thing kangaroos quite badly, once revs are about about 2500 shes quite smooth, and pulls like a train at full throttle.

Have tried changing the AFM and the temp sensor, and cant find an air leak anywhere so im a bit stuck...

Stuball

hot wire systems are quite bad for the stepper idle valve getting gummed up which can cause them to stick a bit. take the valve off and give it a good clean and clean the tube feeding it along with the hole in the throttle. Other than that give the timing a check and stuff like that. No idea what your setup is so its also possible your timing pointer is the wrong one for the pulley making your timing out although it strobes ok. There is also a setup procedure to get the throttle set right for idle, you might be close to the edge of what the idle valve can handle or something like that.

Cheers for that.

Stepper valve/housing and pipes were all cleaned before i put the injection system on.

Ive set the TPS according to RPIs website.

Will check the timing tomorrow.

Stuball

stu out of curiosity try the other stepper motor mate,

Great minds think alike tony.

Have already tried the other stepper motor and theres no change.

Gonna double check for air leaks as well tomorrow.

stu have you played around with the idle mixture screw due to using a free flow air filter on the AF meter???
i had to reset mine when i used a K & N filter,

also you checked to make sure your advance retard on the dizzy is working?

Not Yet, i take it thats the allen head screw next to the butterfly on the plenum?

Im guessing i will need winding in a bit.

cant remember off hand with the hotwire AFM, as not used one for a few years now,
but yeah it is an allen headed adjuster, have you got access to a co meter? or know someone at a local mot station that would check it for you? i think we can goto a max of 2% CO at idle, mine runs at .9-1.0% CO @idle.
also mate suck on the dizzy advace retard pipe to make sure the base plate moves ok, i had a bit of kangarooing last yr, turned out the diaphram on the dizzy was fubbered,

Done a few more tests today.

Its literally the 1st 1/8th of the throttle it doesnt like.

Tried pressing the pedal really slowly, it will either not respond then will rev up to about 2400rpm or relevant to where the throttle currently is., or rev up like it should but run really really rough until i push the pedal a bit more, then it clears up.

Additionally, when test driving, about 50% of the time when you dip the clutch and come off the throttle, it stalls.

Could it be a dodgy TPS?

Stu

stu plug a test meter into the tps and slowly open the pedal it should be a smooth increase as you open the throttle (same way you checked the static settings the other day), this will give you a rough idea if the tps is suspect,
you changed the CO% yet?
checked the vac advance?
checked timing? (8 degrees BTDC)

Tried adjusting the CO% up and down, made no difference to the surging

Timing is set at 8 degrees

Vac advance works fine

Just checked the TPS and its nice and smooth.

Im stumped........

dodgy injectors? spray pattern incorrect?