86 LSC Ignition woes

[Villeo]

So it started with the starter solenoid going south. Replaced that. (once a year...lol). When it went bad this time, the start stayed running. It tried to start with keys out while i ran/tried to start for about 35 sec to get a wrench to take off the battery cable. After this i started the thing at it ran so i thought, good ready to go.

Nope. Now when i start the thing it will only run if i apply about 1/4 throttle and will stumble up in the higher rpm's and will rarely idle. I know that my vr is probably gone again, but this seems different, i was thinking it was possibly the TPS that went out. Just wondering what the opinion on this was.

Oh car is 86 LSC half gtc - it was sent back to the factory after a guy saw an lsc and wanted it to look like one. cool stuff.

Oh and im replacing the ignition switch tommorrow since i looked at the thing and it fell into peices.

I hope i can get this fixed, i love this car. Got it 3 three years ago for $1200 with 86k miles, with near perfect interior and the only problems i've had are starter solenoid and vr.


also should i replace the tfi? and whats a good part number for it? just gonna replace all the stuff that needs to be done.


Thanks in advance!

 

[Villeo]

oh forgot to say that i replaced cap, rotor, wires, plugs, pcv (and yes its still in place), fuel filter and all that about 6 months ago, compression tested the engine, each cylinder passed. no fowled plugs or anything like that. ran fine till the starter got stuck on.

as you can tell im pulling my hair out.

 

[JoshMcMadMac]

Pull codes.

 

[Villeo]

anyone happen to know where the diagnostics port is in the 86 lsc? autozone says in front of driverside strut tower, but all i see is my starter solenoid, and a box with a green and black set of square connectors.

 

[hypostang]

passenger side in front of shock tower near air filter housing

 

[Villeo]

thanks found it...now it wont let me pull codes with a jumper, any special procedures other than those i found on http://www.corral.net/tech/maintenance/eecivtest.html#two

Good thing autozone has a warrenty on thier batteries, i'll need a new one after all this stress on it.

anywho the check engine light is on only with engine not running. i threw a test light at the test port and everything seems to check out.

Anyways, i replaced that ignition switch and tried a new motorcraft VR that i had lying around and that didnt change a thing.

 

[Villeo]

did a test on the tps, shows its shot, so im going to grab one or 5 from the junkyard, along with probably 5 or so tfi's. one of those should be good...lol.

 

[Villeo]

Ok, so i've tested/replaced everything i can try such as. Havent got it to throw codes yet. My next step is checking all the fusible links.

How many links related to engine managment are there? how many links total are there?

Just traveling down the harness from the sensors to the end, at least i can got her to idle mostly, just bogs under throttle till about 3,000 rpm, then it runs as normal.

any other ideas what i could check. Whats the voltage that the MAp sensor should be throwing out at idle?

 

[Magic Al]

OK there's a lot of Fusable Links:

Link "A" is @ LH apron, for Alternator
Link "B" is @ LH apron, for Horn & Lighter
Link "C" is @ LH apron, for Ign Sw & Fuses
Link "D" is @ Start Rel, for ABS Power
Link "E" is @ LH apron, for Rear Defrost
Link "F" is @ Start Rel, for ABS Pump
Link "G" is @ Start Rel, for Ign Coil Circuit
Link "H" is @ LH apron, for Susp Controller
Link "K" is @ LH apron, for EEC Power
Link "L" is @ Start Rel, for Susp Compressor
Link "M" is @ RH apron, for EEC Controller
Link "N" is @ RH apron, for ABS Controller


What it looks like from '89 EVTM

http://thelincolnmarkviiclub.org/Gallery/albums/album94/Charge89EVTMfull.sized.jpg

 

[Villeo]

Thanks a bunch, im going to go test those. I have an FSM but its from the 84, so that does me a bunch of good, but it helps every once in awhile.

 

[Villeo]

Ok so, i found that fusable link M was bad, replaced it, now its fine and running ok at least, still a little missfire feeling.

I then go to start it up a few days later and the thing wont fire, i have spark, full fuel pressure at the rail and of course air. She just wont start now.

Suspect is that the injectors arnt firing, all fusable links are fine. seems like a fuel problem now, how would i go about checking if the injectors are firing and what would cause them to not fire? why would it not run even after it ran a few days ago?

I miss my old carb'd cars with like 6 wires in the engine bay.

 

[OldSchool1]

...
anywho the check engine light is on only with engine not running. i threw a test light at the test port and everything seems to check out.

That is normal operation. The engine light came on because the key was in the run position and the engine was off and the oil pressure was low. Once the engine turns the pump and pressure builds, the light goes out.

Anyways, i replaced that ignition switch and tried a new motorcraft VR that i had lying around and that didnt change a thing.

You need to test voltage while the car is running with a plug and play voltage tester. You're probably spiking which can turn up at the strangest times. Unless your VR was new out of the box, it too could be bad.

You need to go through the charging system step by step. Most common causes are going to be loose connections or bad grounds. If your ignition switch was indeed replaced with a new one, then 75% of the work is done.