65mph+ miss

[mercurygm88]

Im still getting code 11 thats what seems so strange whatever is happening must be something that doesnt throw a code. Ill check em again today that was about a week and a half ago I got the 11. And gadget as much pain as this parts store is being I think there just trying to keep me from buying something unnecessary.

[sly]

compression check time
my 88 has started to do this a little... the engine is getting tired though (100psi on the 2 bangers I checked) It's only got 130K on the ticker too.

[mercurygm88]

checked it about two weeks ago all 8 cylinder were between 150-160psi. I think the only cure im going to find is that if I drive 70 or faster im fine 60-70 ive got the random miss below 60 im fine. It also passes the cylinder balance test with flying colors and as of five mins. ago still gives code 11 both KOEO KOER. Any chance the AOD is doing something strange between 60-70? fluid and filter was changed 10,000 miles ago in june of this year. But the previous owner has the tv cable jerry rigged to the plate on the throttle body because he broke it somehow and it has a bit of slop in it so im thinking if the throttle snaps shut fast it takes a second for the cable to catch up. But I dont know how feasible it is that this is the problem. When I bought the car the tv cable was so badly adjusted at light throttle It would go into OD at about 25mph I made it a little tighter and it now shifts into OD at light throttle at about 37-38mph and under normal acceleration between 50-55.

[sly]

I wonder if the dizzy cap has the loose terminals like that one in scott's junk parts vid. or the coil is producing weak spark.

[mercurygm88]

I wonder if the dizzy cap has the loose terminals like that one in scott's junk parts vid. or the coil is producing weak spark.

possibly I know the first dizzy cap I got for it was a cheapo from napa and it would cause a miss if you revved it in neutral thats when I bought the msd and it went away but its possible for the price I should just go buy one and try it.

[sly]

it's an easy check... just pull the cap and see if any of the terminals wiggle.

[mercurygm88]

it's an easy check... just pull the cap and see if any of the terminals wiggle.

Well I couldn't get any of the terminals to wiggle but I got out my old motorcraft cap and rotor that has all of about 3000 miles on it and popped it on. The problem is nearly gone I mean you really have to be paying attention waiting for it to miss now and who knows maybe its gone and its just in my head but the motorcraft cap and rotor definately made a difference. I know the 5 liter is supposed to be very finicky about ignition system components and I've also heard MSD and ford dont play well together so for now the MSD cap will go in the spare parts in case its ever needed in an emergency situation.

[flyb0t]

Did you check the TPS for a dead spot? That's what happened with ours, among other things. We tested the TPS and came up with a dead spot at about 3/4 open throttle. So you may have a dead spot in your TPS range.

[mercurygm88]

Did you check the TPS for a dead spot? That's what happened with ours, among other things. We tested the TPS and came up with a dead spot at about 3/4 open throttle. So you may have a dead spot in your TPS range.

I did and didnt come up with anything but the TPS and O2 sensors are on my replace list right now. Thats the only two things I can think of that havent been replaced though I think the cap and rotor got it. But I'm gonna get the O2's and TPS while im at it might as well as the originals are nearly 24 years old now.

[1990LTD]

Have fun with the o2s

[mercurygm88]

Have fun with the o2s

I will cross that bridge when I come to it most like next summer the tps I can have done in five minutes the 02's not so simple and my garage is not heated.

[jpc]

TPS and O2 sensor are on my list too! The computer gave me codes for both.

The O2 sensor didn't look THAT bad to replace... I have an O2 sensor socket on the way, and I have a universal-joint socket extension thingy that lets you wrench around corners... how bad could it be....

[LTDMan83]

The O2 Socket and U-Joint will only work on the PS sensor, it fits on the DS one but is too close to the firewall to get the U-joint or ratchet on there. I had to use a regular wrench for the DS, and impact it with a pipe/hammer to get it to break loose. They can be a bear to get off after going through 20+ years of heat cycling.

[jpc]

Oh, there can be two O2 sensors? Herp derp, I'm a dummy. Tomorrow in daylight I'll check for a second O2 sensor on the other side.

If there are two, does code 41 refer to the driver or passenger side sensor?

I found conflicting information on this. This says it's the right side sensor. The manual that came with the Actron code scanner refers to both "EGO sensor" and "right side EGO sensor," and it says code 41 applies to the "EGO sensor". No "right side" so that could be the left side. I guess the Engine/Emissions Diagnosis manual would say for sure but I don't have a copy for '85.

[mercurygm88]

Theres one on either side at the back of the manifold. It could be worse you could have an aero with the 4.6 SOHC and have 4 O2 sensors like my 95 had.