Someone please tell me why my car runs like crap

M

MaddShadez

Registered
My car has had a terrible miss like condition for several months now. i can kinda feel it at idle, every few random seconds it will miss, but only when the car is warmed up. when accelerating it gets terrible up to around 3000 RPM's then smooths out. Any time i speed up, no matter how hard or slow, i feel it. It's really bad when I'm trying to get onto a highway as it shudders so bad it won't downshift and I can't get any speed.

I took it to a local shop yesterday, and after 2 days and tons of tests they can't figure out what is wrong with it either. They thought maybe vacuum leak but couldn't find one. Now they think tranny, but they don't do transmissions so they don't know for sure.

The Tranny fluid was changed about 25,000 miles ago with Mercon V, and I have a J-Moded transmission. The torque convertor is about 4 years old, or 35,000 miles.

The only codes they could pull were

116 ECT Senser out of range
172 EGO not switching (something about lean EXL-bank IV)
225 No knock Signal Detected
632 Trans Control Switch-no state change

They looked into 116 and 225 and said they checked out, and seemed to think none of these would cause my problem. Anyone have any ideas?
 
RE: Someone please tell me why my car runs like crap

As a general rule with multiple unrelated codes, it is beneficial to clear the codes and retest to see which one returns first.

Another cue is sometimes a common ground or common harness connector. In this case that would appear to be connector C118 which is at the driver's side rear of the engine compartment - a 1-1/2 inch square harness connector easily visible from the top just outbound from the brake fluid resevoir towards the fender. Investigate the connection for signs of corrosion(usually a green discoloration).

The typical engine compartment grounds may also be suspect in addition to corrosion in the ground wire from the battery.

G100 - LH side of engine
G101 - LH front of engine compartment
G103 - LH front corner of engine compartment, on front fender apron
G104 - RH front corner of engine compartment, on front fender apron

The symptom change at 3000 rpms however is symptomatic of induction problems since on the DOHC engine, that is the point where the IMRCs typically open. Mechanically, that could be anything from a broken valve spring to a sticking intake valve or other such malady. But it is interesting the shop suspected a vacuum leak. I wonder if they performed a vacuum test. Since the IMRCs are vacuum operated, it is entirely possible one of the actuator vacuum motors has a leaking diaphram. This could be a source of a vacuum leak below 3000 rpms since the IMRCs 'open' via a vacuum solenoid which in effect shuts off the vacuum to the actuators allowing the butterflies to pull open. With vacuum applied(i.e. below 3000 rpms), the butterflies are held shut by the vacuum motor actuators. I suppose a malfunctioning actuator could also lead to a lean burn condition as indicated by DTC 172.

I hope this helps more than it confuses. ::roll::
 
RE: Someone please tell me why my car runs like crap

I was thinking the IMRC's as well and told the guys to look at them, but they said they never actualy found any leaks. I'll check the grounds in the morning, thanks driller
 
RE: Someone please tell me why my car runs like crap

doesn't that figure, i went ahead and was going to look at the grounds tonight, and the assbags didn't bother to put that damn car back together. spark plug wires weren't pluged in all the way, the black plastic cover that goes over the drivers side shock is loose, the screws that hold it in are missing, the EEC test wires are flopping around (where do those plug in at, or do they?) the strap that holds the intake tube on is also missing, and the black wire cover that runs along the passenger fender is cracked in two. i'm going to kill these guys tomorrow. never had a problem with them before, but they just got a new manager last week and he's going to get an earful.
 
RE: Someone please tell me why my car runs like crap

The EEC test plug actually hooks to a false cover which is on the side of the driver's side shock tower cover. FWIW, I relocated mine underneath the cover since I needed a location to mount my PCV separator/filter.
 
RE: Someone please tell me why my car runs like crap

I may have your answer as my car is recently acting similarly funny.

I've had these symptoms on my 93 and my 96. For whatever reason, the spark plug wires on our cars don't do well when sitting next to anything grounded, i.e. valve covers, crossover tube, etc. They tend to easily arc to any ground, and will of course more easily do so if they are old and worn out.

I just moved around my plug wires today and my symptoms are gone. One of them was sitting right on the crossover tube.
 
RE: Someone please tell me why my car runs like crap

I stopped by ford today to get prices for all the missing parts, can you beleive the little metal strap that holds the intake tube in place is $900!!!!!!!!!!!!

The shop found the missing peices except of course for the piece they broke. once i find one they will reimburse me.

I bought some plug wires today from summit, should be here in two days. i'll give it a try. what do i have to lose? thanks for the tip
 
RE: Someone please tell me why my car runs like crap

No, I can't believe that the "little metal strap that holds the intake tube in place is $900!!!!!!!!!!!!".

If it is that expensive, I'll sell you one of mine for half that..:)

I can't even imagine that it would cost 90 bucks.

I think the dealer looked up the wrong part.
 
RE: Someone please tell me why my car runs like crap

Nope, he even included the diagram with the part number next it. i was worried the shop took it to sell on the back market at those prices...:)
 
RE: Someone please tell me why my car runs like crap

[div class="dcquote"][strong]Quote[/strong]
I may have your answer as my car is recently acting similarly funny.I've had these symptoms on my 93 and my 96. For whatever reason, the spark plug wires on our cars don't do well when sitting next to anything grounded, i.e. valve covers, crossover tube, etc. They tend to easily arc to any ground, and will of course more easily do so if they are old and worn out.I just moved around my plug wires today and my symptoms are gone. One of them was sitting right on the crossover tube.
[/div]

We have a winner, the new wires came today, and after 45 min install time the car is running the smoothest it ever has, thanks so much!!
 
RE: Someone please tell me why my car runs like crap

2 days of tests at a shop and they couldn't find worn plug wires? ::roll::
 
RE: Someone please tell me why my car runs like crap

[div class="dcquote"][strong]Quote[/strong]
2 days of tests at a shop and they couldn't find worn plug wires? ::roll::
[/div]

tell me about it, and I always had good luck with them in the past. It is becoming impossible to find a trustworthy mechanic anymore.
 
RE: Someone please tell me why my car runs like crap

[div class="dcquote"][strong]Quote[/strong]
We have a winner, the new wires came today, and after 45 min install time the car is running the smoothest it ever has, thanks so much!!
[/div]

No problem...however my saga continues. Turns out that a bad coil pack caused arcing and really messed up the electrodes on 4 of my copper plugs. I'm assuming a bad coil pack because the other 4 plugs look almost new, even after 15K miles.
 
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