Rough running engine next steps
10-23-2010, 10:59 PM
#1
Rennlist Member
Thread Starter
Rough running engine next steps
I have a 1979 project car that I finally resolved the clutch issue after a ton of other work.
Engine starts but does not accelerate smoothly with the throttle and does not want to go above about 2000 rpm.
What I have done:
new fuel pump
new fuel filter
new fuel lines
new intank pump
tank drained, dropped and reinstalled
new fuel lines front to rear
replaced plug wires, cap and rotor
replaced green wire
plugs pulled, cleaned and gapped
vacuum lines replaced
throttle body removed, cleaned and reinstalled
all ground points cleaned / cables replaced
fuse / relay panel removed , cleaned and reinstalled
new fuel pump relay
What I have not done:
checked timing belt, ignition timing
checked fuel injectors
checked fuel flow / CIS pressures
My question is do I check and set timing before worrying about all the CIS pressure checks. Any recommendations on an order the tackle the next steps?
Thanks
Engine starts but does not accelerate smoothly with the throttle and does not want to go above about 2000 rpm.
What I have done:
new fuel pump
new fuel filter
new fuel lines
new intank pump
tank drained, dropped and reinstalled
new fuel lines front to rear
replaced plug wires, cap and rotor
replaced green wire
plugs pulled, cleaned and gapped
vacuum lines replaced
throttle body removed, cleaned and reinstalled
all ground points cleaned / cables replaced
fuse / relay panel removed , cleaned and reinstalled
new fuel pump relay
What I have not done:
checked timing belt, ignition timing
checked fuel injectors
checked fuel flow / CIS pressures
My question is do I check and set timing before worrying about all the CIS pressure checks. Any recommendations on an order the tackle the next steps?
Thanks
Last edited by jwillman; 10-24-2010 at 12:04 AM.
10-23-2010, 11:24 PM
#2
Nordschleife Master
Hmmmm...sounds like injectors to me. I would guess it would not run hardly at all if the CIS pressures were low. I think injector replacement is quick and easy and not TO expensive (though I am not positive about that on the CIS cars...), cam timing with be more of a challenge to check and correct, but you need to change the T-belt anyway, so that would be the time to do that. Since you need to do the belt, I'd start there, if that is on and not the problem then I'd do NEW injectors (that could EASILY be clogged up and stuff since the car sat so long) and last check CIS pressures and then TRY and figure out how to fix that if it is the problem...
10-23-2010, 11:57 PM
#3
Three Wheelin'
Join Date: Dec 2002
Location: St Louis, Missouri, USA
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I've been in a CIS war (911) for a while now. One test I learned over there that was pretty simple and seems to make sense was to pull the injectors - all of them and put each one in a glass bottle. Then power-up the pump and do whatever you have to do on a 928 to get fuel forced into the injectors while observing the spray and quantity of fuel for each injector. The bottles will appear to be filled with clouds of mist (good). A bad one will probably just dribble and have a lower quantity.
I did all the ignition checks first, mostly because I didn't (and still don't) have the fuel guage set-up.
Bruce
PS...I'm not yet a fan of CIS, maybe next week. Every car should have a device known as a WUR, just bc its wierd;]
I did all the ignition checks first, mostly because I didn't (and still don't) have the fuel guage set-up.
Bruce
PS...I'm not yet a fan of CIS, maybe next week. Every car should have a device known as a WUR, just bc its wierd;]
