Car has running issues

[Texas82GP]

With 85k miles I would suggest replacing the timing chain and gears. In case you misunderstood me, there is a chance the cam is out of time with the crank. Those nylon tipped gears were failure prone. I'm wondering if the popping you describe is the exhaust valve open when it shouldn't be on one or more cylinders.

 

[pontiacgp]

With 85k miles I would suggest replacing the timing chain and gears. In case you misunderstood me, there is a chance the cam is out of time with the crank. Those nylon tipped gears were failure prone. I'm wondering if the popping you describe is the exhaust valve open when it shouldn't be on one or more cylinders.

Didn't they use the nylon gears to quiet them down to prevent the spark knock sensor to back off the timing from the noise from the timing chain?

 

[Texas82GP]

Steve, you may know something I don't. Maybe it would be better to just to go back with a new chain and OE style gears. I wonder where the knock sensor is on those motors. It surprises me that metal timing gears would be picked up by the knock sensor, only because there are plenty of engines with metal gears and knock sensors like SBC, LS, BBC, 60° V6, 90° V6, etc.

 

[oldscutlasswagon]

Here's a small update. I tried to apply vacuum to the egr and I couldn't tell if the diaphragm moved at all. It did seem to hold vacuum though. After that I used my finger to actuate the diaphragm up and down a few times. When I drove the car after that it drove a lot better, no popping, the hesitation was much less noticeable but still there, and the rattle sound was there still but only when the car first got moving. I think actuating it manually partially freed it up. I am going to try cleaning it next and see what happens as I think I'm on the right track. I don't think it has to do with timing at this point, but will be sure to check when I get a chance. Anyone know the OE timing specs for this engine and which plug wire to measure from?

 

[oldscutlasswagon]

Been driving the car more and I'm starting to think it may be something like the timing chain. At light load it behaves normally for a bit but even a slight increase in load makes the car hesitate pretty badly. Im thinking that WOT pulls the timing chain harder against the gears and that's why the car is running pretty bad trying to cruise.
This comes at a bad time if this is what's going on. I would like to eliminate other possibilities first before going down this road, but I am out of ideas besides doing a vacuum test. I don't think this is an ignition problem since it starts right up and hasn't died. Which vacuum port is where I should test from and what readings should I get? Looking at the front accessories/wires/hose makes the timing chain/geare replacement seem nightmarish.

 

[pontiacgp]

A stretched chain will make noise and it can slightly affect the cam timing but it won't change the timing under load. You can see if the timing is off with a timing gun. Have you checked the accelerator pump?

 

[Clone TIE Pilot]

Here's a small update. I tried to apply vacuum to the egr and I couldn't tell if the diaphragm moved at all. It did seem to hold vacuum though. After that I used my finger to actuate the diaphragm up and down a few times. When I drove the car after that it drove a lot better, no popping, the hesitation was much less noticeable but still there, and the rattle sound was there still but only when the car first got moving. I think actuating it manually partially freed it up. I am going to try cleaning it next and see what happens as I think I'm on the right track. I don't think it has to do with timing at this point, but will be sure to check when I get a chance. Anyone know the OE timing specs for this engine and which plug wire to measure from?

Well that means the EGR is suspect and probably should be replaced with a real AC Delco unit. Aftermarket ones tend to have incorrect spec return springs.

 

[oldscutlasswagon]

I can't find a part # for a real AC Delco EGR for California models, I am ready to order one. No smog tech is going to check if it's a CA part number but I am unaware of what the difference would be between the 'national' egr and CA.
PontiacGP you say it won't effect cam timing under load. Is that any load or heavy load? When I put my foot down I can't tell if anything is wrong or not, however even keeping my foot perfectly while cruising still allows the hesitation to start. It hesitates, runs for 5-10ish seconds, hesitates etc... You mention the accelerator pump, doesn't this only enter the equation when my foot initially pushes the accelerator more?
I should add that I used my hand to move the EFE valve, it didn't seem stuck.
I will admit I am pretty upset about this whole thing right now and appreciate all the help.
Information I can still use:
Timing specs: base and total
Vacuum specs: where to measure from and how much

 

[Texas82GP]

Measuring vacuum: connect directly to the manifold. Look for 18"+ at idle on a totally stock setup. You have some good insight above relative to if the problem were the accelerator pump, you would notice the symptoms when you push the gas pedal, not at steady cruise. Steady cruise is when the EGR is going to want to open so it is very suspect at this point.

Don't get upset. You will solve the problem and we will help.

 

[Texas82GP]

What year is your car?