Chugging 94 SC when stomping on gas; help.

bitteroldman

Registered User
Boost guage reads 19 at idle, goes to nearly 15 on heavy throttle (used to only go to about 10-12) and when stomping on gas car chugs badly.

Recent work done was tune up complete with, yes, I know, the screamin' demon coil and the fire wire replacement, worst $250 I've ever invested, and new irridium plugs. Car ran no better after the tune up despite the removal of the plugs that were clearly beyond their life. Car has 51K original miles and car ran fine after tuneup for about two weeks, but now this chugging thing, any ideas? Cam sensor? crank sensor? What the hell are either of those? Oh yeah, new fuel filter too. Would a loose plug wire do this? Thanks for any input.
alex t.
 
Boost guage reads 19 at idle, goes to nearly 15 on heavy throttle (used to only go to about 10-12) and when stomping on gas car chugs badly.

Recent work done was tune up complete with, yes, I know, the screamin' demon coil and the fire wire replacement, worst $250 I've ever invested, and new irridium plugs. Car ran no better after the tune up despite the removal of the plugs that were clearly beyond their life. Car has 51K original miles and car ran fine after tuneup for about two weeks, but now this chugging thing, any ideas? Cam sensor? crank sensor? What the hell are either of those? Oh yeah, new fuel filter too. Would a loose plug wire do this? Thanks for any input.
alex t.


I would start by checking to make sure all wires are snapped onto the plugs, if they are not it may run ok at cruise and light throttle but miss under heavy load.

Charles
 
thanks for your thoughts

yeah, I considered switching back to the old coil, problem is I got sucked into those fire wires and they do not fit the stock coil, so, I'd have to switch out the coil and all the wires and that is just plain not fun. I've just bought a new set of stock wires off ebay, and I may just go back to the stock coil and the stock wires when they come in, unless anybody has anymore suggestions.

and, yes, I will need to verify that one of the existing wires didn't "fall off" although I find that hard to believe that would happen after two weeks of driving fine.

how about them sensors? any possiblities there? I don't know what the heck they even are or what they do, but I've read in some posts that should be replaced....is the chugging a possibility if one of the sensors is bad?

alex t.
 
naw, not the maf, but thanks

not the maf, cleaned that and no difference. Although when I first bought the car I posted here trying to figure out why it was such a dog off the line. I stumbled across cleaning the maf and then the car was a beast off the line. actually, I can still burn the tires with the current problem, it is just that at speed it stumbles and chugs when you nail it.....keep them thoughts coming, this newbie, and frankly man without a clue, appreciates it.
alex t.
 
Im a bitter old man also but dont let that get in the way of owning a awsome car. My first was a 94 and i had lots of things I wanted to replace but the fuel pump on 94-95 cars seem to go out a lot sooner as miles dont seem to matter. It seems to be age, how ironic but its hard to check fuel pressure at WOT. If I were you I would just replace it now as it will need it soooner then later. Your looking for at least a 190 walbro pump I beleave that is the correct spelling but what do I know. hope this helps.
 
bitter old man unite!!

Thanks for your comments. Actually, I'm a pretty laid back guy that is why the bitter old man moniker is a joke, although the wife says it is beginning to fit.

Yeah, the car is really cool. I bought it for my son, aged 18, after his 3000gt got smashed (not his fault, broadsided by a gal) and failed to let him know just how much daddy likes these cars. Now I pretend to be helping by filling up his gas tank but in reality take it out to beat the heck out of it....brings back some good memories. (I'm actually looking to pick up a 1994 or 1995 for myself now.)

I think this weekend we will change back to the stock coil and wires and see if that does anything. I may just toss in a new fuel pump to so that I can rule that out...thanks for your thoughts.

alex t.
 
Thanks for your comments. Actually, I'm a pretty laid back guy that is why the bitter old man moniker is a joke, although the wife says it is beginning to fit.

Yeah, the car is really cool. I bought it for my son, aged 18, after his 3000gt got smashed (not his fault, broadsided by a gal) and failed to let him know just how much daddy likes these cars. Now I pretend to be helping by filling up his gas tank but in reality take it out to beat the heck out of it....brings back some good memories. (I'm actually looking to pick up a 1994 or 1995 for myself now.)

I think this weekend we will change back to the stock coil and wires and see if that does anything. I may just toss in a new fuel pump to so that I can rule that out...thanks for your thoughts.

alex t.

have you checked pressure at the fuel rail yet? Should be 40psi I believe. Theres really so many things it could be. Maybe TPS? but I'm not sure
 
Resolved issue

Okay, thanks again for all the input, thought I'd just stop by again and advise as to what the problem was in case it can help somebody else out in the future........the darn coil was defective.....really nice that it works great for one week plus then craps out.....I've contacted the place I bought it from and while they seem to be helpful all they have done so far is to notify the manufacturer but I'm still waiting to hear from them. So, at this point, I for one would say to avoid the Screamin' Demon coil....wish I had.
alex t.
 
Boost guage reads 19 at idle, goes to nearly 15 on heavy throttle (used to only go to about 10-12) and when stomping on gas car chugs badly.

alex t.

Are you saying you went from getting 10psi at wot to 15psi now?

that could mean you need to replace your cats...just a thought.

does this chugging happen all the timek only when cold, only when hot?

if there isnt a miss at idle i dont that a plug wire fell off.

check the gap of the plugs, and make sure the cats are not plugged..or be prepared for some headgasket work.
 
DIS and plug wires

I had the same problems at one time, replaced the plug wires with taylor , but check them at night they might be arching, if you get a dis try the motorcraft. I bought a standard after market and it only lasted one year, and make sure you put the grease under it before you torque it down. Go to a pick a part and get yourself one or two motorcraft dis modules. You can use this for checking when your car starts to get the hickups. If you cant find an SC at the junk yard look for a Taurus SHO same dis.
 
Sound slike a clogged cat. Went from 10-12 to 15psi? on full throttle????

Could be a clogged cat...

As far as disregarding that make sure your wires were snapped on well at teh plugs.

I just did Autolite xtremes and the same coil pack with no issues
 
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