Alright SHO masters, I’ve got a serious problem, and I can’t figure out what it is. I drive a 1992 MTX SHO. It idles fine, but at the lower end of the rev band (1k-2.5k), there is a hesitation and backfire. After I did the plugs and wires, the car ran fine for almost three weeks, then the hesitation came back. I had remembered finding oil on the old spark plugs, so I thought it best to go ahead and replace the plug well seals and the valve cover gaskets. I did the gaskets today, and the problem was gone for the first 2-3 minutes of driving. It felt weaker than it should, but the hesitation and backfire were gone. Now, it is back to its old self again. The hesitation, backfire, and bucking are all back, as bad as ever. What can I do? This has become very expensive and very frustrating.
Hesitation, Backfire, and Frustration
- Thread starter EXP1787
- Start date
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Dr. Tweak
Mad Scientist
Is there oil in the plug wells again? Did you use RTV on the plug well seals?
Also if your wires were damaged (from oil in the plug wells) you will need to replace them again.
Also if your wires were damaged (from oil in the plug wells) you will need to replace them again.
Dr. Tweak
Mad Scientist
What about this? If you put new wires in and ran them with oil in the plug wells they can ruin your wires...
masho95
got Zex?
Is the hesitation and bucking always there? Or does it come and go? Perhaps it was just coming and going while you were trying to change things. CMP sensor (camshaft position sensor)
It is always present in the lower RPM range. I checked the plug wires again today, and still, no sign of a problem. Perhaps when I get some extra money I'll pick up another set of wires. Could it really be the CPS? I wouldn't think that it would cause the car to behave as it is...
projectSHO89
SHOless In St L
Try running with the CID (cam) sensor unplugged and see if it works correctly.
Be aware that the engine may take several attempts to start and once running, you will have a CEL.
If the bucking and hesitation is gone, that will confirm the CID as your problem. If it makes no difference, plug it back in and keep working on your diagnosis.
Steve
Be aware that the engine may take several attempts to start and once running, you will have a CEL.
If the bucking and hesitation is gone, that will confirm the CID as your problem. If it makes no difference, plug it back in and keep working on your diagnosis.
Steve
TucsonSHO
New Member
Sounds a lot like this frustrating hesitation i had for several months. Turned out to be a pinhole near the bottom of one of my spark plug boots. New plugs would get rid of the hesitation for about 20 miles or so. I guess the carbon build up and elctrode wear are inevtitable reducing the conductivity of the proper path for the spark.
I would clean your wires with electrical cleaner, maybe the plugs too if theres any oily film on them, and very closely inspect your plug boots for arcing residue. Also, the new motorcraft plug for our cars, though controversial to say the least, should help there as well. Less spark is aledgedly required due to there new "fine wire" design, despite the lacking prescence of precious metals.
Good luck-
Clovis
I would clean your wires with electrical cleaner, maybe the plugs too if theres any oily film on them, and very closely inspect your plug boots for arcing residue. Also, the new motorcraft plug for our cars, though controversial to say the least, should help there as well. Less spark is aledgedly required due to there new "fine wire" design, despite the lacking prescence of precious metals.
Good luck-
Clovis
TucsonSHO
New Member
I would strongly advise against those wires oh . I would only trust Motorcraft or Taylor wires. The Motorcraft wires can be had for less than $100 at
FordPartsNetwork.com
and the fit perfectly. Hope whatever wires you go with work for you-
Clovis
FordPartsNetwork.com
and the fit perfectly. Hope whatever wires you go with work for you-
Clovis
Dr. Tweak
Mad Scientist
What evidence are you using to back up those claims? Not that I want to start an argument, it's just that I don't like it when people make ignorant comments. Have you used AC Delco wires?
There are a number of people on this board who have been using AC Delco wires for some time with no issues. If it's the fit you're concerned about, take a look at this SHO with new AC Delco wires, as you can see they are a perfect fit and seat tightly where they should:
<small>[ March 26, 2004, 04:40 AM: Message edited by: JDLangevin ]</small>
TucsonSHO
New Member
I haven't used the ac delco wires myself, but I had a friend back east who had some issues with them seating correctly. I'm not sure if they have been revised since then. Past that, I ronically enough, yesterday i was driving to phoenix to pick up my brother from the airport. Around casa grand I saw a sho stranded on the other side of the road. Seeing as I had most my tools with me, extra fluids and several parts I fealt obligated to stop (especially seeing as friendly as all of the phoenix sho owners i have talked to hear have been). He was overheated so i gave him some coolant and water. When doing so i noticed some oil coming out of the plug wells near the top. I was trying to explain to him what to do to rectify the situation, and in doing so pulled a wire only to have it fall apart, into 3 pieces!!! Sure enough they were delco wires, not sure if the overheating was a chronic condition and it deteriorated them over time. Good thing Tom from phoenix had given me a spare wire for the one i have damaged.
So i'm not sure if this was just all coincidence that my only two experiences with these wires sucked, but that coupled with all the post I read on this forum saying only taylor or motorcraft lead to that statment, even if I did jump the gun a little.
So i'm not sure if this was just all coincidence that my only two experiences with these wires sucked, but that coupled with all the post I read on this forum saying only taylor or motorcraft lead to that statment, even if I did jump the gun a little.
revhardSHO
SHO Member
I would think the build quality of the AC delco wires would be less than the OEM motorcraft wires (pretty good quality wire), and they look a bit thinner in diameter to.
still, Im going to try a set next time i pull the intake off just for kicks
still, Im going to try a set next time i pull the intake off just for kicks
Dr. Tweak
Mad Scientist
I've compared the Motorcraft and ACDelco wires side by side, they are the same diameter and the construction is EXACTLY (as far as I can see) the same. You can see in the pic above that the fit is just right, and the wires look just like the MC.
Perhaps your friend from the east was not running the correct plugs? Because if so then no wires would seat correctly.
I have had some extensive conversations with a lot of people about the ACDelco wires, and I've come to the conclusion that they are at least the same quaility as the MC. However, there are wires out there (Taylor) which are higher quality than both the MC and ACDelco, obviously.
When you look at the MC wires it looks like they were made by ACDelco. I'm not saying that this is the case, but that is how it looks. The ACDelco wires even have the exact same clear plastic wrapping that are on the MC wires and vacuum lines.
*edit* Also, in ref to the comment about the ACDelco wires coming apart, the Phoenix Project had MC wires when I got it, along with oil in the plug wells, and when I pulled the number 5 wire out (trying to find the source of a hesitation) it broke apart. So I find it unlikely that they were constructed better than the ACDelco.
<small>[ March 27, 2004, 02:06 AM: Message edited by: JDLangevin ]</small>
Perhaps your friend from the east was not running the correct plugs? Because if so then no wires would seat correctly.
I have had some extensive conversations with a lot of people about the ACDelco wires, and I've come to the conclusion that they are at least the same quaility as the MC. However, there are wires out there (Taylor) which are higher quality than both the MC and ACDelco, obviously.
When you look at the MC wires it looks like they were made by ACDelco. I'm not saying that this is the case, but that is how it looks. The ACDelco wires even have the exact same clear plastic wrapping that are on the MC wires and vacuum lines.
*edit* Also, in ref to the comment about the ACDelco wires coming apart, the Phoenix Project had MC wires when I got it, along with oil in the plug wells, and when I pulled the number 5 wire out (trying to find the source of a hesitation) it broke apart. So I find it unlikely that they were constructed better than the ACDelco.
<small>[ March 27, 2004, 02:06 AM: Message edited by: JDLangevin ]</small>
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