87 Firebird 2.8 Manual.
I have got it to run 99% well. Idles okay. However.... there seems to be some jumpiness/jerking at low throttle and deceleration (totally fine when you stomp on it).


I was looking at the distributor and noticed that if I grab the rotor I can turn it a little way (whilst I do that it rides up a bit).
Is that normal and could cause the above symptoms?


Thanks,
Rhys

 

the rotor, under the cap, usually they have a LITTLE slop. so if you grab it with your mit and go left to right, there will be a little slop. If there is a lot, either its loose or the gear at the end of the dizzy is worn out.

Sounds like the jumpiness may be a fuel related issue.. Im not familiar with the 2.8, but I can gaurentee that ppl here do. Hang in there!

-Dan

 

I rechecked the timing and it's on. However on idle sometimes it misses just slightly and the timing jumps away and straight back. Does that every few seconds randomly.

I checked fuel pressure. 41 psi key on only. Steady 45 psi at idle. Blips to 40 psi when throttle blipped. Does not leak after 10 mins.

Hmm, what can the problem be? Anyone got ideas what to check next. I have another distributor but the magnet looking thing looks cracked.
Rhys

 

The hold down bolt can feel tight but still allow movement, had to really horse mine down when it started to move a bit. tiny move one way, runs like crap, tiny move the other, ran great......

 

Thanks Gumby, I will try moving the timing over a bit and see if it improves.
Anyone know why the timing 'twitches' sometimes when I have the light on it?. Is that normal (yes the EST wire is disconnected)