OxmanWI

Ignition problem

96 thunderbird 4.6.... She will pulsate / vibrate when I put my foot on the gas. I had my buddy Marve (auto tech) take it for a test drive and he said that it IS a ignition problem. A strong smell of gas out of the exhaust too! Any one have a problem like this before, ignition wise? Spark plug going? Wires going? Coils? Help!!

Poobs

Your buddy must be good if he can tell you it is ignition by just driving the car

The smell could be unburned fuel because there is no ignition there to fire it up or because the fuel is beign dumped...

How many miles on the car?

Did the problem start all of a sudden or did it get worse slowly over days/weeks?

When were the plugs changed ?

Do the wires look ok or R they dry, rotted ,nicked & caked with crud.

Same for the top of the coils - R they clean ?

What are the other maintenance items like - air filter dirty? Fuel filter ?

Is the motor stock?

Giving your buddy the benefit of the doubt - It is easy enough to change the plugs especially if they are known to have high mileage.

Basically if you pull them out and they are all soothy ( black but not shinny) You COULD have a rich condition ( too much fuel) affecting all cylinders.

If you find some looking light brown and some looking soothy you Could have bad wires.

If all the soothy ones are fed by the same coil pack it COULD be the coil pack that feeds those plugs.

Now, the above is only a general aproach..... Sometimes an ignition problem can make it look like an over rich condition or a misfire due to something else can make it seem like the other two reasons are the cause.

U would have to eliminate one of the posible factors such as the plugs and then go on trouble shooting from there.

good luck

OxmanWI

90,000 miles

It got worse slowly over days/weeks, it happens whene ever, one day it will happen and the other it wont, last night it happened after work and i got home let it set over night and the next morning its running fine.

Plugs not sure but i know they have less then 30k on them they should still be good

Wires look good, new air filter, clean MAF, new fuel filter

I have a 4.6 supercharged allen kit

I have been running rich, its a crapy mail tune, I'm in the works with a dyno tune in the next couple of days, but the car has been running rich for a while...something like 15k miles....

Poobs

I would not bring a car to a dyno unless I know it is in good shape. It is a good idea to have a look at those plugs....

Chopper

Get the car tuned and let us know how it's doing.Ninety thousand miles is a lot for ignition wires,they usually are shot by 75,000.When they go it's usually an "every time" kind'a thing though.I would get a new set of Moroso,MSD,or the equivalent,spiral wound,low resistance wires and put them on before the dyno pulls.
You can listen to the injectors with a long wooden dowel or screwdriver to make sure they are all working.They should all sound about the same.
Repost and let us know how it turns out.

Poobs

good point !!

OxmanWI

I have MSD 8.5mm wires, they should be good, the SC kit was put on around 35K miles ago along with the plugs.

OxmanWI

Well i cant get to my TPS and IAC cause they're under and behind the intercooler, and im not taking any thing apart. BUT i did pull the plugs out and i think i found my problem...

#1 plug gaped at: .039
#2 plug gaped at: .040
#3 plug gaped at: .037
#4 plug gaped at: .040
#5 plug gaped at: .045
#6 plug gaped at: .045
#7 plug gaped at: .043
#8 plug gaped at: .028

I'm waiting for Fed-Ex to come and give me my new wires so i have the new plugs in right now, all gaped at .037. So dont know if it really was the plugs that are giving me a rough idle. So now i play the waiting game...thanks Fed-Ex[:'(]

Poobs

Plug gap is not the problem and I would be VERY surprised if it is the wires.

Were the plugs fouled , oily or soothy or heavy yellow deposits ?

OxmanWI

Well i changed the plugs and wires and sure eough it did not slove the problem...Now im thinking its a bad injector, maybe stuck open?