I have an '89 camaro w/ a 2.8 and every time I begin to accelerate the car hesitates for a second and then accelerates. I thought I read something on hear a while back about this being caused by the timing chain but I couldnt find the post. Any idea what's causing this?

 

I think anybody with the 2.8/3.1 has this symptom at some point .I member a thread started on this back a few month ago,Where me and fellow from Cali went back in forth on the issue.I think we both came to the conclusion that the ECM is set to very lean values/tables for this engine for emissions/fuel economy.I have all new sensors and a new timing chain and I still have the hesistation especially when cold.When it warms thats when it appears to go away,which is consistant with a lean fuel mixture.I believe a better set of injectors is possibly the fix or find someone to burn a PROM.Otherwise ,your not alone ..I just hink nobody has actually found or did anything to solve it and posted it here yet.I will sooner or later ,looking at the injector upgrade first then I will go from there.

 

I fixed my vacuum leak (in the hard plastic lines, didn't even see it nor could I find it with carb cleaner, but only fixed when I replaced every single vacuum line) and the hesitation went away.

I still have a very slight dip at about 2500 rpm but I thought that was more due to the torque converter or tranny. At least it feels that way.

When running, my 89 2.8 runs incredibly well in the cold.

 

i just recently replaced my intake manifold gaskets and solved my hesitation... the bolts to the intake manifold were so loose i could use one hand to loosen them

 

vaccume and such would cause that, as will bad timing. a while back my car was doing this and i thought nothing of it until my fuel pump took a dive. then i found out that hesitation when hitting the gas can be a symtom of a fuel pump on the way out. It's worth the $20 for a fuel guage to find out in my opinion.

checking your base timing and looking for vaccume leaks like everyone said are also good things to do. i replaced ALL my soft and hard vaccume lines a while back when i had the upper intake off, it did not change anything (car had no problems at the time) but it was deffinatly a good idea.

good luck.

 

I'll say this ...I have replaced all sensors except knock and VSS,replaced all fuel system components...pump/injectors/regulator/even the relay.I have also did all the timing components...timing chain,module,pick-up,ignition coil,cap,rotor,wires,and plugs.I either blocked/disabled/repaired all the vacuum sources,and I still have the hesistation.I was considering disabling all the vacuum sources from the engine and driving it .If it clears then its in a vacuum source ,if not its in the engine itself or the ECM values.I have access to Mitchell On demand at work and only see a similar problem with this area and it was an updated PROM.I called the local dealer and was told that I have no update for my car.If these cars came from the factory with this issue then why isnt there more complaints in the Mitchell On Demand?..I am considering worn camshaft lobes or lifters?..A worn cam or lifter would not produce a good valve lift,which would create low engine vacuum.It would have to be something internally worn is what I am getting at?..Its a process of elimination again?..