Strange no-start troubles

[Arc Angel]

Hello SHO Guru's. I just started having trouble starting my 94 SHO ATX. A few weeks ago, when it started getting cold up here in PA (single digit temps), the car would take two attempts to start...then run fine. Once warmed up, it would start on the first click of the starter. Last week, it would take dozens of trys before it would finally start.
New parts - fuel pump, strainer and filter...IAB...Cam Position Sensor...K&N Air Filter...spark plugs and wires...new starter and battery...ignition switch and steering column key lock cylinder...
No codes have shown up, either. It just now takes roughly 12 to 20 trys before it finally starts running...it cranks over fine, fuel pressure is up, the fuel pump is running, but, no ignition (ie. starting) - once it finally starts, then it runs fantastic.
Any clues on what the heck I can check to correct this problem? I'll probably fry my nice new starter if I keep this up.

Thanks,

Frank

 

[Bruce M]

Check grounds

Check to make sure that the back of the DIS pak mounted on intake is making a good solid connection to chassis ground. Don’t just check to the tube that its mounted on only. Go from the plate of the DIS pak which is circuit ground for that device (you can get to it with any meter probe) right over to the negative battery. That should read near “0” ohms. Anything like 20 ohms or 50 ohms is no good. These cars are notorious for that. The cold up here in the northeast plays havoc with connections. Start there if that’s OK, check the connections to the ignition coil pack, and check for cracks on that. Next time it won’t start get out and check for spark during those times. That will put you in the ballpark

Keep us posted.

 

[93rev2sev]

I would not go very much further without seriously considering the Crank Position Sensor as the culprit. If it gets worse (IE wont start...period), I would change that sensor immediately.

If possible, check this area for gunk and grime (yes you will have to take the crank pully off). My thought is that the rotor has a bunch of gunk on it, interfering with the CPS signal.

 

[Bruce M]

92Rev2Serv is right. check that Crank Postion Sensor first. I thought that was on your list of things that you replaced. See if there is fluid from the water pump leaking down there if there is that could be your problem. thats common with these cars. The DIS pak on these cars have been know to go too.

 

[Arc Angel]

Okay. This morning I took off the DIS module, and it was gunked in old dielectric grease, so I cleaned that all off and soaked the back with WD-40 and re-installed it. Then I checked every single ground lead from engine to body - all good. I sprayed B-12 Chemtool down and around the crank pulley (as a temp hopeful fix if it's just the grime stopping the Crank Position Sensor)...
Got in the car in a good mood, thinking I found the culprit with the so-so ground behind the DIS - cranked it...and cranked it...and cranked it...a few times (this time) I got some rather serious backfires...then on about the twenty fifth crank and the battery almost gone - it finally started. Ran fine.
Drove to work about ten minutes away...stopped the car. Went out three hours later - still no start - just cranking away.
I was mistaken with the earlier post - this starter was not new, so I just am in process of replacing this starter. It was pretty darn grimy down there with the wire harness and the wires leading to the selenoid, so I'll see what happens tomorrow when I get the brand spankin new starter in.
Thanks for the pointers, everyone. I'm praying it starts tomorrow and I don't have to tackle that Crank Position Sensor...

Frank

 

[1QuickCoupe]

I had the same problem about two months ago. I first replaced the crank sensor and got the same results. The cam sensor got replaced and it fixed the problem. Hope you get it runnung!

 

[TimboSHO]

After my troubles with a 94 ATX that didn't start and I thought it was the crank sensor, and it ended up being other things(including the CPS), I wouldn't assume anything. Check this out and diagnose it before just replacing the CPS.

http://www.frontiernet.net/~miketoni/images/tbird/DISnostart/DIS No Start.htm

EDIT: FIXED!

 

[93rev2sev]

Linky broky