Okay, so on my 2.8 its cur renting popping sometimes through the intake. I have replaced wires/cap/rotor/fuel filter/CTS, timing with EST disconnected shows to be running at 10. Any ideas on what to check? Would low fuel pressure cause this problem?

 

was it doing this before you replaced this stuff? are you getting a check engine light ever? does it do it hot or cold or both? when it does pop, is it shifting or just randomly doing it? try and get more details about when it happens.

 

When I originally bought the car it was running utterly bad. Popping, hesitation, surging, bad shifting. After replacing all of this stuff, the car runs pretty damn good. When it is first started(cold) it will usually try an hesitate a little bit/possible die when first putting it into gear, and tends to pop more(both intake and exhaust). As the vehicle warms up the intake popping seems to go away, and h'm left with the very random, rare exhaust pop from time to time.

There is never been a check engine light code on, after warming up a bit she idles at 600 with no flu cations on the tach gauge in the car. I've replaced basically all the vacuum lines except for perhaps anything under the plenum. I've cleaned the IAC, the throttle body, set the TPS and checked its range which seems to be fine.

The only thing I can think of is perhaps the MAT/IAT sensor, however from my understanding with this being a MAF car, it only effects EGR operation, and I don't believe that would cause intake/exhaust popping though I could be wrong. The other possibility from what I have gathered is a fuel problem(low PSI, though this seems odd as the problem seems to go away for the most part, or all together as the car warms up.) or valve lash/valve problems.

Just not sure where to really go with it at this point.

 

i'd start by checking the fuel pressure.

 

Thats what I've been thinking as well, just been trying to avoid needing to buy that fuel pressure gauge. Oh well time to add another tool to the old collection I suppose.

 

does your check engine light even work? when you turn the key ON but dont crank the car, is it on? if its not, you may have codes and never know it. also, your EGR may have a block somewhere. i had a vacuum line that was plugged, and it would cause a back fire whenever my car was warmed up.

as for checking the MAF, with the car running, tap on the MAF sensor, if theres a change in idle or stumble or anything like that, you need a new one.

 

My check engine light does indeed work, i've seen it come on and stay on while trying to get ALDL data logging to work. It also is on before starting the vehicle and with the key on.

I have tried tapping my MAF and noticed no change in engine performance.
I have blocked off a few vacuum lines(I removed the entire emmisions cansister and purge valve system as it was toasted, and doing so actually helped out drivability alot(vacuum leaks))

How would I go about checking the EGR?

Thanks

 

I would check/replace all of the gaskets, check for holes in the EGR tube that runs to the manifold, and then see if the valve itself will hold a vaccum. I would do this be taking it off and compressing the valve and put your finger over where the vaccum line hooks up and see it the valve stays where you had it set. Also check any of the vaccum lins that are part of the system.

 

Intake popping can be caused by running lean. If you know how to connect a multimeter to your O2 sensor, do so. If its running under 0.3V you've got either a bad MAF or plugged sensors.