65mph+ miss

[miamibob]

Snowing in Canada in late December? Unheard of!!!

[mercurygm88]

Im starting to think it may be a good idea just to ignore it and see what it does over time. Maybe in the spring or summer ill feel ambitious enough to do some gasket and vac line replacement. But im not gonna do it in the snow.

[miamibob]

You're as picky as I am - IT'S A GOOD THING! However, if it is not screwing with your MPG's or driveability I'd leave it for the better weather.

[mercurygm88]

Well im still getting 23-26 mpg on the highway so it can wait.

[1990LTD]

im gonna say unlikly but, i never like to rule anything out when not sure of the parts. my brothers 88 town car does a similar thing but does it a lower speeds. you feel the miss here and there. iv done alot of testing and what not, to the EEC components. i have no codes, and get 90s on cylinder ballance tests. i am looking for vac leaks now. i have done EGR/throttle body gaskets and checked hoses, so far. one thing i notice and will replace next, is the plenum gasket. where the lower and upper intake(plenum) meet, its very black. it is just like that, only around the gasket area. one can only think, that there is a leak and its sucking the leaky oil, from the rocker gaskets. i will try to get a pic, if i can open the hood, since its covered in snow and ice from yesterdays snow.

they're all like that if they've been used. just blackened from EGR and PCV gases.

[marquisman]

this cant be normal. lol

[sly]

considering EGR gases and PCV blowback... yeah... it can. Just means the gasket has worn out. New gasket and enjoy. And check the PCV valve/screen. That's one of the easiest gaskets to replace if the screws holding the name plate down on top aren't seized up.

[marquisman]

here is another pic.

the gasket is the onlything ti have not touched lol. the black shit made me think about leaks. when i get a chance, i will replace it. things come apart pretty nice from this car. here is a pic(i never posted pics of this linc) of the patient.

[sly]

you might check for seepage from the EGR spacer of coolant if the coolant lines are still connected. Hopefully that's not an issue.

[marquisman]

no seepage. just did the throttle/EGR gaskets. ever since i did the seafoam treatment, the car idles high. good, but high. me thinks the carbon has been washed away from the gasket area, inside and caused vac leak! i know the theory sounds good lol.

[sly]

sounds like a good theory to me. Still needs new gasket.

[marquisman]

^i think your on to something sly! ...on a side note, i sounds like a total n00b lol

[mercurygm88]

Ok so today I went out and sprayed some WD-40 in the egr solenoid (popped off the cap and filter and sprayed it down in there). I noticed that if you put your finger over that little hole in there that it will cause the engine to run rough and if you leave it on there too long it will die is this normal? The only other thing I found is that if you put the car in park or neutral and rev it up there is a certain rpm range about 1/3 throttle maybe a little more where this miss will happen below that its fine above that its fine. Its a great enough miss that when in park or neutral that you can hear it through the exhaust and it slightly shakes the car. Dont know if this helps but I ask two local autoparts stores about a high rpm miss on a SEFI 5.0 one told me to check timing (later today) the other said it sounds like I have a collapsed lifer (I doubt it) or a valve floating but if I did why would it go away if I went faster wouldn't it just get worse?

[mercurygm88]

Ok so found out if I rev the engine in park or neutral it will miss quite often somewhere between 1/4-1/2 throttle if i speed it up no miss slow it down no miss so its rpm specific. Hence the reason it doesnt do it under 60 or over 75 and of course I cannot find anyone else who has had the same problem. Today I checked the timing and its set perfectly at 10* BTC also replaced the tps due to a dead spot causing sputtering on slow acceleration so I fixed that but still have the miss. At this point im not sure if I should just start throwing money at it or leave it go till it either gets worse or goes away havent checked codes in a week or two I'll check em tomorrow but im sure I'll still get an 11 any ideas? Just a recap new plugs,wires,rotor,cap,IAC,TPS,egr solenoid,ignition coil,battery,alternator,map sensor,TFI module and im sure theres something else im not thinking of all this has been replaced since the beginning of july 2011. About the only things I havent replaced are the Air Charge Temp Sensor which I dont have a clue if it could cause this or not, and the O2 sensors which I doubt are bad because I still get 23-35mpg on the highway.

[mercurygm88]

As a last resort im replacing the dizzy on thursday or friday. If that doesnt do it ill just have ignore it until it gets worse or goes away.