hesitation 89 park avenue

[jeff32111]

I will try to make this short.I just replaced my harmonic balance a couple weeks ago.That was the latest work i have done to my engine.Well just a couple days ago i started getting a hesitation when i press the accelerator.Seems like when i just feather the gas pedal it wont hesitate as bad as when i push it like normal.Once i get up speed it seems fine but the hesitation is really bad like its bogging down.I noticed when i have it in park and rev the engine up i hear a little backfire or popping sound from the muffler.Any ideas on what could be causing this?Could the crank sensor cause this since i did change my harmonic balance?I changed out my ignition control module a year ago but that could be it too maybe?Well any help will be greatly appreciated.Thanks
Jeff

[Alibi]

Any trouble codes? It kinda sounds like a plugged up cat converter or a muffler with broken baffles. Cat converters last about 150k miles, not sure on the muffler.

It could be that your timing is off too. The timingchain and gear only last 75k-125k in this era of the 3800.

A bad crank sensor genearlly causes hard starting problems. I doubt that you have a bad ICM if you just replaced it but you can pull it off and have it tested at an Autozone or an O'Reily's if you want to be sure.

What about your plugs and wires? How old?

[jeff32111]

Well the plugs and wires were changed when i replaced the ICM.I did the plug wires,plugs,ICM,and coil pack.It got a lot worse today.And when i got home i looked at the exhaust manifold toward the firewall and it was glowing red.Would a clogged up cat cause it to do that?It got so bad today going up any hill it almost wouldnt make it.I know it ran hot but no engine light came on.I havent checked codes yet i guess i gotta do the paper clip trick.But from what you said im leaning towards the clogged cat.Any quick fixes if thats what it is?Thanks for your help

[Alibi]

Yup..... your manifold was going cherry?? Wow....yeah, Definately replace the cat converter. NOW would be a good time. Could be that the muffler is plugged, too, but I would guess the cat converter first. Should be about a $100-150 or so for a reliable shop to replace it. I found a good cat on ebay for around 60 bucks, had it installed for another 60.

You prolly ought to replace the O2 sensor too if the manifold got that hot. They're only about 20 bucks.

I really can't think of anything else that would cause this, unless you are running a bottle of heet or other fuel additves without enough fuel to dilute them. You haven't been running anything other than 87 octane either, have you? Higher octan fuels will clog the emissions system really quick on this car simply because the engine wasn't designed to burn the higher octane fuel.

To recap: Change your cat.

[jeff32111]

Nope i havent put any additives in my car.I only use 87 octane also.At first i thought i got some bad gas or something but today it ran hot and that manifold was glowing red right at the O2 sensor.I will change my cat before i drive it again and the O2 sensor.Thanks for the help that really makes me feel better now i know what it probally is.

[jeff32111]

Well i removed my Catalytic converter today just to see if the sluggish hesitation would go away and it didnt.It even wasnt starting up real smooth like it usually does.I drove it maybe a half a mile and i come back and the exhaust manifolds were both cherry red.What could be making my car get so hot so quick like that?I would have thought if it was the CAT then that would have made the car run smoother.I was thinking maybe it was a blown head gasket but i would have noticed it to be a lot louder if that was the case right?Anyone have any ideas what could be causing this problem?The car still acts real sluggish....once i get speed up to like 35 or 45 its not to bad but just not right.

[HotZ28]

Have you changed the fuel filter or checked the fuel pressure at the fuel rail?
This sounds like a "lean" condition!

[jeff32111]

No i havent changed the fuel filter or checked the pressure at the rail.This problem could cause the car to run hot?And it runs hot in such a short drive?Do you have to have a guage to check the pressure at the rail or just hit the valve and see if it spurts out?

[HotZ28]

Starving for fuel could cause a lean condition and in turn could cause the extremely hot exhaust. You need to use a fuel pressure gauge on the rail to get an accurate reading. Good pressure reading would be 38-44 psig at idle.

[jeff32111]

The weird thing is i changed the fuel filter today and no change.But whats weird is i can rev the engine up in neutral and park and get a good response out of the engine.When i put it in reverse or drive its super sluggish.Could this be a bad transmission now?And could that also make the exhaust so hot?

[Alibi]

Wow....that is just really really wierd.

The only other thing I can think of is a really stretched timing chain?? But that doesn't make sense either. Anyway, go on the track that HotZ suggests now.

Ok, you changed your fuel filter so what you need next is a fuel pressure gauge. You can buy one, or I believe you can rent one from Autozone. It just screws onto the schrader valve on the fuel rail.

If it is low, then we're looking at a weak fuel pump or possibly a bad fuel pressure regulator (this would be much easier and cheaper to replace before the pump). I never thought low fuel pressure would cause the manifold to heat up so badly though....learn something new everyday though, eh?

[wrightz28]

Originally Posted by jeff32111

I will try to make this short.I just replaced my harmonic balance a couple weeks ago.That was the latest work i have done to my engine.

This would leave me to think that theres a problem between the way the blades on the back of the balancer for crankshaft position sensor pass through the sensor and the sensor may need adjusting, or a bent blade, seen that before.

[jeff32111]

Well i was wondering if maybe i didnt get the sensor correct enough when i changed the balancer out....if the sensor isnt right would that make the car run that hot though?I was told today it could be my torque converter since the car is so sluggish in drive and reverse and the engine sounds ok when in neutral or park.The converter locked up or whatever could make it run hot and would be a reason the car is sluggish up hills and now its even sluggish on level ground.I can mash the gas pedal and the car doesnt have any power

[Bassasasin]

I was thinking too your so called harmonic balancer area is the problem since it seemed to start there with your post.

Did you replace it? Could it have rotated?
Did you replace the Crankshaft sensor?

The popping may be mild backfiring.

I wouldnt run it in this condition.


Good Luck

[wrightz28]

If the snesor is not reading correctly then it's massively misifiring, hence the sluggish respaonse, backfing, and yes it will run hotter.

Ditto w/Bass, stop driving it.