7mge help! wont rev

[Thetankwad]

just built up after a bhg. new cyl head, the lot. Have checked all sensors and all are plugged in, and am now at the tune stage.

Not a master mechanic, but kno enough to do this on other cars.

Car will fire up. Car will idle. as soon as any gas is even hinted, the revs drop and it dies. I have not tuned it with regards to the dizzy advance as i have no strobe, and the engine dianosis has not thrown up any errors. Is this how it is when the timings not set? Surely i thought it would rev rough?

Help me obi wan, your my only hope!! :banghead: :rant:

[Chewie]

Mine does that,cos some twit had tried to ajust the idle screw! :banghead:
When its non ajustable :no:

[Bionic]

distributor timing or air leak at a guess
did you get my PM?

[adi]

AFM normally does that.. other than that i have no idea.

[Bryank]

just built up after a bhg. new cyl head, the lot. Have checked all sensors and all are plugged in, and am now at the tune stage.

Not a master mechanic, but kno enough to do this on other cars.

Car will fire up. Car will idle. as soon as any gas is even hinted, the revs drop and it dies. I have not tuned it with regards to the dizzy advance as i have no strobe, and the engine dianosis has not thrown up any errors. Is this how it is when the timings not set? Surely i thought it would rev rough?

Help me obi wan, your my only hope!! :banghead: :rant:
What do you mean, dies? does it just die quietly, or spit/pop make nasty noises?

Unlikely to be the timing, if it idles ok.. (would bog or spit if you rev it with bad timing, unless it's REALLY out, but then it probably wouldn't idle..) But I would beg/borrow a strobe from somewhere and check it for certain.

would have thought if the afm was not working, then a fault code would show? check it i guess.. make sure the flap isn't jammed.

Unplug and replug all the connectors.
Check the valve timing. Possibly one tooth out.
check all the vac pipes are connected, and you've not got a damaged pipe anywhere, or an air leak.
When it dies, pull a spark plug out see if it's wet. (eliminates a fuel problem).

Hope that helps..

Cheers,

Bryan

[black 86 supra]

What do you mean, dies? does it just die quietly, or spit/pop make nasty noises?

Unlikely to be the timing, if it idles ok.. (would bog or spit if you rev it with bad timing, unless it's REALLY out, but then it probably wouldn't idle..) But I would beg/borrow a strobe from somewhere and check it for certain.

would have thought if the afm was not working, then a fault code would show? check it i guess.. make sure the flap isn't jammed.

Unplug and replug all the connectors.
Check the valve timing. Possibly one tooth out.
check all the vac pipes are connected, and you've not got a damaged pipe anywhere, or an air leak.
When it dies, pull a spark plug out see if it's wet. (eliminates a fuel problem).

Hope that helps..

Cheers,

Bryan


a quick one from me but it doesn't sound like a timing problem, it wouldn't idle as good as your saying and should still rev just cough and splutter at the same time, It def sounds like an air leak somewhere so check all vacuum pipes for connection and or leaks.

[Finfon]

sounds a bit like a problem on my dads sierra the other week turned out to be the fuel pump! probably miles out here tho :)

[Tony Donovan]

Is the electrical connector to the AFM seated properly? Happened to me.. Doh! :)

[Thetankwad]

checked the cam timing, its ok.
all hoses are good,
petrol is definetily reaching the cylinders
guess its an electrical fdault then, nite nip to a scrappies and pick up another afm just to rule it out. I'll keep u posted...

oh, and it coughs and splutters then dies, not just cutting out. Dont know if that makes a difference...

[Finfon]

sounds a bit like a problem on my dads sierra the other week turned out to be the fuel pump! probably miles out here tho :)
is the fuel getting to the cylinders at a high enough pressure? as on the sierra there was a large drop in pressure due to a tired pump

[Bionic]

checked the cam timing, its ok.
all hoses are good,
petrol is definetily reaching the cylinders
guess its an electrical fdault then, nite nip to a scrappies and pick up another afm just to rule it out. I'll keep u posted...

oh, and it coughs and splutters then dies, not just cutting out. Dont know if that makes a difference...

have you checked distributor timing I know you havent got a strobe but if you follow distributor replacement in the online tsrm you wont be far out

[Bryank]

have you checked distributor timing I know you havent got a strobe but if you follow distributor replacement in the online tsrm you wont be far out
Was my thinking also... sounds supiciously like the timing is too advanced.. try knocking it back a few degrees. Surely someone near you has a strobe....?

[Thetankwad]

cheers for all the help so far chaps, had to conceed and part hands with it to a garage, who so far have discovered that a number of the cylinders are flooding. My injectors were lying in a sorry state when i got the car( :flush: ), could this possibly be the root? Also, i am not 100% sure the connectors to the injectors are the right way round, is there any test method to prove what terminal matches what cylinder?