power loss / low rpm's

[SHO~OFF]

I've got a '91 sho plus, mocha frost, factory fiberglass hood. Recently it has lost power and the rpm's are low. I think I hear a plug wire arching but I'm not sure. Going to change those, but I was wondering if anyone knows anything else to check. It does have a cat free exhaust. Thank you for any help.

 

[rubydist]

first, pull the codes. there are detailed instructions here on the forum as well as other places online. all you need to be able to do is count (or take a video and post it so we can count for you)

there is a good chance that if a wire is arcing, then the plug wells are full of oil. if so, you need to clean that out carefully, and replace plugs and wires.

 

[sperold]

Everyone could use a little more information.
The catless situation contributes to a loss in low end performance, but from the info we have, it sounds like that did not happen recently.
New Motorcraft plugs and new wires go a long way to solving problems.
Vacuum leaks, usually from under the intake, can affect things dramatically and usually happen 'all at once".
Depending on how long ago the maintenance was done (front and top 60K), it is possible the timing belt jumped a tooth, but that is in the "long shot" category.
Does "revs are low" mean it will not go over, say, 3000 rpms?

 

[SHO~OFF]

Everyone could use a little more information.
The catless situation contributes to a loss in low end performance, but from the info we have, it sounds like that did not happen recently.
New Motorcraft plugs and new wires go a long way to solving problems.
Vacuum leaks, usually from under the intake, can affect things dramatically and usually happen 'all at once".
Depending on how long ago the maintenance was done (front and top 60K), it is possible the timing belt jumped a tooth, but that is in the "long shot" category.
Does "revs are low" mean it will not go over, say, 3000 rpms?

Yes, it will barely get to 4000 rpm's, but pulls steady as if it were an average Taurus engine just no kick. It comes and goes. This morning i killed a 2009 or so acura tsx. 5 miles down the road went in to McDonalds, left and the car had no power. Also happens while driving. Will lose power and/or gain power going down the road. Thank you for responding. I don't want to let this car go. I need to get it right.

 

[SHO~OFF]

first, pull the codes. there are detailed instructions here on the forum as well as other places online. all you need to be able to do is count (or take a video and post it so we can count for you)

there is a good chance that if a wire is arcing, then the plug wells are full of oil. if so, you need to clean that out carefully, and replace plugs and wires.

Ok, cool. I pulled the codes yesterday morning (thanx to post I read here) and am going to change the wires and plugs tomorrow (pay day lol). At least I know I'm on the right track. And coming here was a good start. Thanks for the info and anything else you might can tell me about this car.

 

[rubydist]

what are the codes???

we can only help you if we know what they are...

 

[SHO~OFF]

I will post them in the morning around 8 am eastern time. They are at work.

 

[SHO~OFF]

Do you know where I can find out how rate my sho is?

 

[zoomlater]

Here's a link to the production numbers, follow the link to the cached page

http://www.shoforum.com/index.php?threads/sho-production-numbers.128508/#post-1423634

 

[AREA 91]

You have a 91 Mocha Frost plus?
That is my dream SHO!
You interested in selling it?

 

[SHO~OFF]

Becoming very interested in selling. It's getting to be too much work for a daily driver.

 

[SHO~OFF]

It runs strong but has an issue with cylinder 5. I'm at work checking it out between jobs now.

 

[luigisho]

Codes codes codes...

How many miles on it? Maintenance performed? Better info in, better info out

 

[SHO~OFF]

Almost 200,000. Here are the full symptoms after these repairs. New plugs, wires, coil pack, camshaft position sensor seal. Start the car in the morning, runs perfect, shut off 2 miles away at the gas station, restart and low rpm's and loss of power. Or it will run fine all day. Or it will start like crap, then while driving, the rpm's will jump up and it gets full power. And visa versa.

 

[SHO~OFF]

Timming belt and all in with it appears fairly new and everything there is dry and clean. No maintenance record.

 

[SHO~OFF]

I keep screwing up on getting the codes. Miss counting or something. Maybe if I do it while not at work where I have to hurry. Duh. Lol

 

[rubydist]

just post a video of the flashing, there are several of us online that know how to count.

 

[SHO~OFF]

Ok. I just want to give a great big thank you to all the great people here. Thanks to all the help, I'm on the path to fixing my power loss problem. #5 cylinder not firing all the time. Changed plugs, wires, coil pack. Seems to be in the harness. Any thoughts where are very welcome.

 

[luigisho]

Could be a few things. Harness is possible as well as other things like a faulty computer, DIS, injector and more. Codes would help narrow it down or maybe pay a competent Ford tech with good diagnostic equip to pinpoint it. Have you tried to wiggle the wiring harness while it's acting up to see if that affects how it runs?

 

[rubydist]

the harness will not cause the #5 plug to not always fire. the spark system on these engines is a wasted spark setup, which means 2 plugs are always fired together - one on the combustion stroke and one on the exhaust stroke. if there is a problem with the harness/coil/dis then you will get a misfire on #5 and also on #2. if you only get a misfire code on #5, that suggests that you have a problem with #5 cylinder itself or possibly that plug or wire.