Problem On The Way Into Work This Morning - Fixed

S

stpete

Well-Known Member
Dec 26, 2015
320
151
63
#1
I'll start with the back story. I had taken the Mustang into the garage for some work and done a little disassembly. My sons car needed a starter, so I put the Mustang back together and pulled it out. It didn't run well at all, I had to move it a coupe times to get it out of the way of other cars and was running badly and showing a CEL. I later diagnosed that as forgetting to hook up the MAF after putting the CAI back on.
Forward to this morning, MAF now hooked up and off to work. I noticed early on that the tach would occasionally jump around. Nothing else going on with the car, but the tach would jump anywhere from a couple hundred to 1500 RPM, then back a few times very quickly. Later in the drive the car was missing pretty badly as I slowed for some traffic and sped back up. I was concerned I would make it, but it settled back in and I had no further issues other than the tach jumping.
My first thought is the *&^%ing TFI again. Any other ideas are appreciated.
 

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#3
stpete said:
Tried to go to lunch ... no joy. Thing starts and runs rough for a few minutes and then dies. Not good.
Click to expand...
I believe that the tach signal output comes off of the coil it'll be the orange wire on the coil. If I'm not mistaken you may have a failing pip sensor you can try diagnosing this by removing the spout and trying to start the car the car should not start with the spout removed if it does it's likely the PIP sensor in the distributor.
@jrichker for the checklist
 
#4
Three things, 1 never guess, it's expensive and frustrating. 2 run a dtc codes test with a scanner, and 3 , check fuel pressure at rail. Your problem is probably electrical, from your comments, but be sure. Most of your parts and franchise repair facilities do the dtc codes test for free. If you can get it there. You can buy an EEC scanner for under $80.00. Good to have around.


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#7
I have a code scanner. Didn't have it at work with me though.

Had to leave the &%$ing car and get a ride home. Will pick up with my trailer tomorrow. I ordered a distributor since it's the only thing that's not new in the ignition chain related to the tach. Also got yet another TFI and the remote mount for it.

Trying to make this thing reliable is proving to be more difficult than I expected. Not too happy about that, been having serious thoughts of getting rid of this thing lately. Every time I fix something I think it should be good to go. Now I'm coming back to stuff I already fixed .. POS.
 
#8
Parts are trickling in, hopefully I'll be able to get it on the trailer after work. Haven't tried since I got the lowering springs on it.

After more reading, it seems like the tach path includes the Coil, TFI, and distributor. So, those are the parts I'm focusing on for now. Reman distributor in hand, Motorcraft TFI coming tomorrow. I have the coil I replaced laying around, it's probably still good. So, I should be able to replace and check. I've ordered the McCully racing TFI relocation kit. Haven't heard anything from them yet, but I'll fix first and add that when it shows up.
 
#9
Are you getting any black smoke when it fires and died? Smelling fuel? Check fuel pressure, pull vacuum line at fuel regulator. Make sure your problem isn't fuel. What codes are you getting?


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#10
stpete said:
I have a code scanner. Didn't have it at work with me though.

Had to leave the &%$ing car and get a ride home. Will pick up with my trailer tomorrow. I ordered a distributor since it's the only thing that's not new in the ignition chain related to the tach. Also got yet another TFI and the remote mount for it.

Trying to make this thing reliable is proving to be more difficult than I expected. Not too happy about that, been having serious thoughts of getting rid of this thing lately. Every time I fix something I think it should be good to go. Now I'm coming back to stuff I already fixed .. POS.
Click to expand...
I have been driving and fixing these 5.0 Fox Mustangs for 25 years now and have had to have the car towed less that 5 times. Granted there were some strange things that happened during that time, but I have been blessed that the necessity for getting towed home wasn't one of them.
 
#12
It's not, just wondering if he's he's having more than 1 issue. I've seen vehicles that have fuel and electrical problems at same time. He's had recurring problems. His jumping tach is obviously electrical. But starting, running rough, then dying, can be fuel, or fuel/ fuel injector components. I've been working on cars/ trucks since 1970, yeah do the math I'm 61, I've owned 3 mustangs, 2 Lincoln mark 7's, all with 5.0 engine. I now have an expedition 5.4 engine. I've seen more than a few problems with these engines. Just trying to help kid get his car working right. I give advice on 3 forums. Not to mention have worked at dealerships/ my own repair shops. You know we learn something new all the time. I just helped a member on this forum that had 1 cylinder fail due to a bad tfi module. I've never seen that before. They usually fail completely, or run, overheat, stop run, cool, run. Never rule simple things out. That's why we test, test, and test some more. Saves mis diagnosis and wasted parts.


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#13
It did smell like gas when I got it fired to get on the trailer. But, it took about 15 seconds of cranking before it fired. One of the times I was cranking it I kicked the gas pedal and it fired, so ... not sure there's really anything to go on there. The only thing I know for sure is that it's getting worse.

Helping this KID ... ha, good one.

The lowering springs made things tough. I had to jack under the front of the trailer to get it flatter and the front of the car still rubbed a bit. Fun. Now to get it back off and into the garage. Not sure if I'll mess with it tonight or not. Have a headache from hell.
 
#14
Pulled the car off the trailer and stabbed in the new distributor. No joy. Initially fired for a second then died. Back to long periods of cranking with short periods of running, those periods are longer if I hold the throttle down but no chance of idle for more than a few seconds. Changed out to my old/spare TFI module and it ran and attempted to idle and surged a few times. Much better, probably just needs timing set and will be as un-trustworthy as it was when that TFI module was in the car before. I guess I'll wait for the new module to arrive tomorrow before I bother to set timing. Will have to stop at radio shack for more goop also, I think this is the 7th or 8th time I've changed the TFI. Hopefully I'll hear from McCulley and have some idea when I'm getting the remote mount. I'll see if I really want to get the car back out or not. Hopefully that's it and I'll be done with this ridiculous ignition system.
 
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#16
Moosee1955 said:
It's not, just wondering if he's he's having more than 1 issue. I've seen vehicles that have fuel and electrical problems at same time. He's had recurring problems. His jumping tach is obviously electrical. But starting, running rough, then dying, can be fuel, or fuel/ fuel injector components. I've been working on cars/ trucks since 1970, yeah do the math I'm 61, I've owned 3 mustangs, 2 Lincoln mark 7's, all with 5.0 engine. I now have an expedition 5.4 engine. I've seen more than a few problems with these engines. Just trying to help kid get his car working right. I give advice on 3 forums. Not to mention have worked at dealerships/ my own repair shops. You know we learn something new all the time. I just helped a member on this forum that had 1 cylinder fail due to a bad tfi module. I've never seen that before. They usually fail completely, or run, overheat, stop run, cool, run. Never rule simple things out. That's why we test, test, and test some more. Saves mis diagnosis and wasted parts.


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Click to expand...
Relax killer, i don't think he was checking your credentials there. Maybe he just wanted to know what lead to that question. Trying to see connections that for you may be simple logic. Questions help us to learn, right?

I've been reading your replies and i believe you have a lot of knowledge. I also believe you'll be a great resource for us.

I'm glad you've joined us.
 
#17
Just noticed your 49, still a kid to me. Try Bayer, with a Budweiser great for headache. You'll figure it out. Check out pick up coil / tfi thoroughly. Tell me your not running a cheap Chinese ignition coil? Do a wiggle test on wires going to and out of distributor. Check all your grounds. Everything clean and tight? Load test battery. On expeditions that I also advise on cause all kinds of crap when battery's questionable. Keep us posted. 6 buds work better than 1 for headache, Moose! Sorry I get kinda carried away. Just like to help where I can. When I was learning cars, very few mechanics wanted to give up info. You shouldn't be having this many distributor issues. Are you 100 percent sure you have sound wiring/ computer?


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#18
I reread your first post, you stated your maf sensor was disconnected and after reconnecting that and stabbing in starter, all your woes began. You might want to backtrack, and check wires at maf plug, as well as sensor itself. Also this sounds nuts, but check positive cable at starter, and grounds. If your problem was distributor related, the new one should have corrected your problem. One last thing, and I might be way off but check electrical part of ignition switch and wiring. Who knows after starter install might have messed something up there. Lincoln's are famous for the ignition electrical switch failing. Just another thought.


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#19
Hey Pete, have read a million times all the posts, and still haven't seen one where you ran dtc trouble codes, why? It sure would narrow down your symptoms. Please run codes, and post results.


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#20
All a matter of time. So far most of my issues haven't thrown any codes, but I will check them. Going racing tomorrow so otherwise occupied with the racecar today.

Could be wiring, definitely going to run another engine ground. That may be leading to all this. MAF is new, battery is new.
 
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