93 8v rough running then only idles

[cav24v]

OK... I have a '93 Cavalier SRI 2 litre 8 valve... Its run well for many many years, recently when warm I have had some issues with it hanging back slightly then you would loose power and it would die, if I left it for a while it would then start again. It could then run OK for weeks, Took it for an MOT last week and on the way home it messed around again, so I stuck a new fuel filter on it, ran it up for half an hour and it seemed OK. It finally died completely the other day. SO I have fitted a new crank sensor, rotor arm good 2nd hand coil, a known good air flow meter, ( plugs and leads new a few months ago. Then I could get it to tick over fine but every time I tried to rev it it killed the engine/it died, but it would happily tick over. Since fitting the filter the fuel pump seems to have got really noisy, so I am just waiting for a new one to arrive which I will fit.

Has anyone got any ideas as to what on earth is going on please??

[James McGrath]

Definitely could be the fuel pump causing you trouble. All the symptoms seem to match.

See if you can find somewhere that can do a fuel pressure test. That should tell you if it's the pump or not.

[Robsey]

Sounds like identical symptoms to when I fitted my C20NE, but still had the single point injection fuel pump in place.

Fitting a multi-point injection pump cured the issue.

So it definately sounds like your old fuel pump is dying.
Be sure that you have ordered the correct pump... as there are two.
SPi used for 1.6 and 1.8 engines.
MPi used for all 2.0 engines.

If the pump is noisy, it could be that the intake is blocked allowing the inner bearings of the pump to run dry.

Or something could be loose and is rubbing or vibrating.

Before ordering a new pump, I would have took the old one out again and checked that nothing had been dislodged or moved.
If all seems normal but the noise continues, then a new pump is your best bet.

[James McGrath]

Correct me if I'm wrong Robsey, but I believe the Bosch Part number for the one you need is: 0580314097

[Robsey]

Yes James.
That is the correct Bosch part number.

There are plenty on ebay etc...

[cav24v]

Sorry I should have said, i have removed the pump to check the filter first and checked there was nothing adrift in the tank too. thanks for the input when i get the pump i will update you.