95-MTX: Power Falls Flat @ Secondaries

[BRD]

View media item 707I've been having misfiring and power issues on my 95 MTX which I attributed to leaking o'ring seals, but have just replaced them, and I'm still getting the same power loss. (I have a 92-MTX to pull parts from, and could use some assistance on where to start.)

The car starts and runs perfectly, right up until the secondaries kick in and you can hear and feel it start to go, but then it just falls flat, as if I completely removed my foot from the gas pedal (when it's actually floored). This lull will stay flat until I lift my foot off the gas pedal. On occasions, if I let it wrap up slowly, the butterflys will open and the car will cruse right on up the tach.

Any tips and/or ideas?

 

[Irish Pride]

Have you pulled codes? If so, what are they?

I had the same symptoms with a bad Throttle Position Sensor one time.

-Chad

 

[Jbeck]

plug wires might be toast if they were in oily spark plug wells for too long. replace those wires and see if the problem still exists after that...I would bet no

 

[BRD]

Thanks for the tips. I also replaced the plug wires. (plugs, wires, and valve cover gaskets & o'rings).

I will look into a TPS, and the MAF since it's an easy swap.

 

[rubydist]

yeah, we need to know what the stored codes are.

 

[BRD]

It's been sitting for a year without a battery, will the codes still show? I've never pulled them, but have read of the paperclip trick somewhere.


Edit:
Pic from this morning added to top post.

 

[zoomlater]

Codes will show again (if there are some) now that you ran the engine.

 

[BRD]

OK, thank you! I will try to pull them this evening.

(Irish Pride, sorry I overlooked where you mentioned pulling codes previously.)

 

[RonPorter]

Also check the psi of the fuel pump at the rail. Should be close to 39 psi.

 

[BRD]

I picked up an ODB1 scanner, and no codes were available. I drove it and was able to get a check engine light to come on by hammering the throttle and holding it on the highway, but the light went back off before I could get pulled over to test, and then no codes showed again.

I tried to remove the TPS from both (92MTX & 95MTX), but they didn't budge.

Also check the psi of the fuel pump at the rail. Should be close to 39 psi.

OK, thanks. I'll have to research how to do that.

One thing I noticed is the connector with one wire, a gold wire on the intake, barely has any covering on it. Is this a ground or something and/or should it be fully wrapped?

View media item 708

 

[luigisho]

What kind of obd scanner did you use. Alot of them do not work properly on this obdI system. I would try the jumper method and see what pops up. The car should not have a CEL and not have a code. It's not impossible i suppose but if I had CEL and no codes I would get suspicious of the computer.

 

[BRD]

I purchased the only OBD1 scanner Autozone had, see image:
View media item 709
I will try the Paper Clip Method next.

The CEL only stayed on until I slowed to a stop, shortly after it came on (It was only on for about a minute).

 

[luigisho]

Yeah. That one might work. Nick uses one that works I think. Maybe he'll chime in. I would Check with paperclip, if nothing, drive until the CEL pops again and paperclip again. So we are sure this is not the oil light, abs light etc? Did you noitice any operating issues with the light on?

Now that I am looking at the pic, what am I looking at? That wiring looks hacked up. I don't have my car at my location to compare.

 

[Irish Pride]

Try the paper clip method. I'll bet you get some codes.

 

[luigisho]

Chad do you know what that wiring is on the intake aft of the DIS? Is that solid exposed copper? The pic will expand if you click on it.

 

[BRD]

Chad do you know what that wiring is on the intake aft of the DIS? Is that solid exposed copper? The pic will expand if you click on it.

That wire is partially exposed, it has a plastic yellow/goldish colored casing. It looks like once it reaches the conduit it becomes exposed.

It's pouring atm, so I will snap another pic this afternoon, and will try the paperclip code read test this evening.

 

[luigisho]

yeah I copied it and blew it up some more. I see it now

 

[Irish Pride]

If it's coming from the Crank Sensor (single black connector) then it's not supposed to be fully insulated. It's supposed to be unshielded.

 

[BRD]

That would be it, the light colored wire with a black colored male end fitting in your image. Glad that is it intended to be exposed.

 

[BRD]

So we are sure this is not the oil light, abs light etc? Did you noitice any operating issues with the light on?

Regarding the Check Engine Light, it was a Yellow light that said Check Engine. I do also get a Red ABS light occasionally, and the Airbag warning bell/buzzer goes off on startup sometimes.