Hesitation and Stalling around 1500-3000 RPM's

[94GPGTP]

The plugs look dark.. Hmm.

That "sensor" on the coil pack bracket was the evap cansiter purge soleniod lol.

Anyway, Take the vacuum line off the FPR and smell it and see if there is gas in it. Perhaps it's leaky and causing it to run too rich... Other than that a fresh O2 sensor might help but it could *possibly* be the 3/7x CPS.

Also you don't have a vacuum leak do you? Perhaps the LIM gasket is really bad off on it? I'd replace that if you plan to keep the car anyways as you don't want coolant in the oil...

LOL.. I figure i'd change it since it was there..

I have been hearing the O2 sensor could be bad and can be causing this.. i have checked the FPR and it is good no fuel smells or fuel coming out the vacuum port.. what do you mean the 3/7x CPS.. Crank Position Sensor?

I dont have a vacuum leak that i know of.. it idles fine and dosent miss a beat at idle or doesnt go up or down.. I dont understand what you meant the LIM gasket is really bad off on it... Off on it?? huh?

I do plan on keeping it.. it does have 167,000 so its probably in need of a LIM... also to get off topic here the temp is a constant 210.. why??

Thanks for the help!!!!

[IsaacHayes]

Yes the crank sensor in the block. There is another one (24x) on the timing chain cover but you gotta pull the harmonic dampener to change that one. The 24x one is for low RPM and idle stability, possibly it could be bad and cause your issue, but the 7x one is the one that always gave me trouble. If you could scan with a laptop and TunerPro RT I have a definition file that would reveal lots of info.

I meant if the LIM is bad off (bad condition) on the car. Yeah that many miles it should need a LIM gasket badly...

Temp, perhaps the thermostat is sticky, or flow is reduced due to dexcool sludge in the system.

[94GPGTP]

Yes the crank sensor in the block. There is another one (24x) on the timing chain cover but you gotta pull the harmonic dampener to change that one. The 24x one is for low RPM and idle stability, possibly it could be bad and cause your issue, but the 7x one is the one that always gave me trouble. If you could scan with a laptop and TunerPro RT I have a definition file that would reveal lots of info.

I meant if the LIM is bad off (bad condition) on the car. Yeah that many miles it should need a LIM gasket badly...

Temp, perhaps the thermostat is sticky, or flow is reduced due to dexcool sludge in the system.

Sometime in its lifetime it has been converted to green...

Ill change that CPS and see what happens from there..

Possibly will change the LIM and lifters and rockers to get that tick/knock out of the top end...

[94GPGTP]

Here's a video!!!

http://www.youtube.com/watch?v=7Gk7u1HErfw

Copy and paste that into your browser if link doesnt work..
Let me know what you think.. thanks

[IsaacHayes]

Wow, ok, uhm that's defiantly not normal ticking noise/chain slap on a 3100.

Something is wrong there LOL. It could be a loose rocker but that does not sound good. That's enough noise that I'm wiling to bet it's registering knock counts and pulling spark, perhaps that's why at that RPM it falls on it's face because it might be really pulling spark at that resonance. I would pull the valve covers and check the rocker arms and then if that doesn't help I would probably be looking for a new motor.... Cheap 3400's can be had and then you get a little more power at the same time.

I mean I guess it could be the timing chain slapping the guide but mine never was that loud in videos. It may be I'm just hearing that along with the other loud noise in your video.

Here is mine before replacing the timing chain (noisy)
And Here is mine after timing chain. (intake manifolds are different, but same heads/block.)
Here is how loose the chain was causing the slap.

But yeah sounds like you have other issues..... ouch...

[94GPGTP]

im going to check them rockers.. i have a good feeling its them because the noise is on the very top.. ill check it out.. thanks for the help.. im not giving up yet!!! i have a parts car which is the one to the left in the video... its black also and has a 114,000 mile 3100 in it so ill use that if needed..

[bszopi]

Without watching the video, I bet I can guess the problem (from experience), although with it being a 96, it might not be... BUT, if you have pushrod guides, I bet one of the fingers on the guide busted off, and the pushrod slid out from under the rocker. The pushrod is still being moved by the lifter, and its bouncing off the valve cover. With the pushrod no longer moving the rocker (and thus the valve), you are minus 1 cylinder, and depending on which one (intake or exhaust), you are either pressurizing the cylinder or drawing a vacuum in it on every stroke, thus causing your hesitation.

[IsaacHayes]

Yeah 96 should be roller fulcrum rockers (no guides) but I think from that info you posted a while back Brad that a few 96 were not.

If he does have a broken guide then yeah that could be it since he had a miss-fire code on cyl 2... Would be easy to look at with the front valve cover off.

What causes the guides to break? Metal fatigue? But there's not really stress on them... ???

[bbeck]

I went to replace my crank position sensor, and it broke off in the block. Will I be able to push it out of the block by removing the oil pan? Or would I have to remove the crank?

[IsaacHayes]

The 7x one? can you try to grab it with a magnetic tool to bring it up closer to then grab with pliers?

[bbeck]

well, it broke off about flush with the block on the outside of the engine. I've already tried to drill a hole and run a self-tapping bolt in it to pull it out, but had no luck. Can the sensor be pushed out of the block from the inside without removing the crank?

[IsaacHayes]

If you had the pan off I would guess so (just reach between the crank and grab the sensor). But taking the pan off is a big task at least on my 3100, plus you probably have to drop the sub-frame to clear it like mine....

I'd try to remove it externally some more before going to all that hassle...

Try a dry-wall screw... they are nice and sharp and might grab the plastic sensor better than a self tapping bolt.... If you can get 2 of them into it, opposite each other then you have something to grab and twist/rotate the sensor back and forth as you pull out. The o-ring on the sensor likes to get stuck sometimes and twisting and pulling works great.

[bbeck]

I'll give the two screws thing a try tonight when I get a chance. It's not too bad to pull the oil pan on the 2.8L. I just lift the engine a bit from above, and IIRC, it comes right out. Other than the starter and the inspection cover for the trans that is. Does anyone have a pic of the sensor on the inside- where it meets the crank? Just to get an idea of how much room I'm working with.

[IsaacHayes]

No picture but the hole is pretty close to the pan and the bottom of the block since the mains protrude somewhat into the oil pan.. I can't imagine it being that hard to fit a few fingers or a plier to push it out with...

[bbeck]

wow!! that thing would have never come out without pulling the oil pan. I had to pry on it to get it out. But, the oil pan came out pretty easy- just drained the oil, dropped the starter, and pulled the trans inspection cover. It comes out without even lifting the engine. It all looks good inside, other than the chunks of rubber I found in the oil pan. How hard is it to do valve seals in these motors? And which ones should I get?