Engine Please Help Me Diagnose Issues With My 5.0...

Discussion in 'Fox 5.0 Mustang Tech' started by 5.0 CJ-7, Feb 24, 2014.


  1. 5.0 CJ-7

    5.0 CJ-7 Member

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    This may be the only question I can actually answer. LOL!

    The passenger side manifold is from a 1984 Ford F-150 302. The driver side manifold is from a 1984 Ford F-250 351. Along with the exact part numbers for the Goodyear radiator hoses, that is the only information I have written on paper by the person who built the Jeep.
    Last edited: Mar 5, 2014
    #61
  2. 5.0 CJ-7

    5.0 CJ-7 Member

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    Update 3/4/14 (part II)

    This evening I had a friend come over to help me check the distributor. We located TDC on cylinder #1 and found that the distributor was pointed directly at spark plug wire #1 just as it should be.

    We then experimented with advancing the timing in two degree increments up to about 18 degrees. The engine ran like crap no matter what we set the timing at. We were able to observe a few interesting things with the timing light, however. First, at idle the timing was consistent. Second, at a throttle position just above idle the engine kept surging along with the timing visibly increasing and decreasing. Third, at just a slightly higher throttle position everything smoothed out again. Fourth, on more than one occasion we noted that the flashing of the timing light seemed to slow way down (like almost half of what it should have been).

    We then decided to switch around the spark plug wires to the non-HO firing order. After doing this, the engine would only crank with no attempt at starting. I thought to myself, "Great! We just verified that it is an HO motor." We put the spark plug wires back in the HO firing order and discovered that the engine still would only crank with no attempt at starting. At this point I thinking something along the lines of, "Are you freakin' kidding me?!" Further testing revealed that there was absolutely no spark at any of the cylinders or coming out of the coil.

    With the TFI module and the distributor barely even warm to the touch, I estimate that we spent the next 30 to 40 minutes discussing the computer, the TFI module, and the pickup sensor as possible suspects for this extremely depressing ignition failure. During that time several unsuccessful attempts were made to restart the engine. It wasn't until we decided it was time to start pushing the Jeep off the street that it miraculously restarted. For perhaps 30 seconds it seemed to actually run well, but then it went back to running like crap again. We quickly moved the Jeep off the road and then let it sit idling while we discussed the absurdity of everything that had happened. Within about 15 minutes the engine died and would not restart again. Before walking away in absolute disgust I noted that the TFI module and distributor were much warmer but not even close to being too hot to touch.

    Thoughts?
    Ideas?
    Suggestions?
    #62
  3. FoxMustangLvr

    FoxMustangLvr Advanced Member

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    I have nothing that can help you but I have to ask this question.....why bang your head against the wall with this mickey mouse combo?

    A 4.0L inline 6 w/ turbo would provide everything you need or even a turbo diesel? Are you in love with the idea of this Jeep being so unique that you'll spend 99% of the time trying to debug a poorly planned rig instead of enjoying it out on the trails with friends with the occasional repair and upgrade? I love hitting trails too and I know for sure that when you do those long trail runs you need a bullet proof reliable rig. Breaking a shaft, rolling over, getting stuck is all part of the game so why add such a headache combo to a hobby that's already intense and time/money consuming. I'm a 4runner guy but I have loads of respect for Jeeps too.

    JEEP (Just Empty Every Pocket)

    Good luck with your passion project, there are some smart people here that will continue to help you along.

    P.S. Why not hit the junk yard or craigslist for a running 5.0 High Output (preferably from an Explorer, more TQ) w/ MAF and grab it along with the computer and swap it out? You could probably get one for $500 or less and be done with this and be hitting the trails this spring.
    #63
  4. 5.0 CJ-7

    5.0 CJ-7 Member

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    I'll ignore the implied insult of this question since I'm not sure whether or not you meant for it to be negative. To address your comments and questions in general, it would be stupid of me to spend large amounts of time and money on another engine for the Jeep. Your philosophy equates to telling every Mustang owner who posts on this forum with engine problems that they should pull the engines out of their cars and replace them with something else instead of fixing whatever is wrong. That obviously makes no sense.

    In case you missed it elsewhere in this thread, the Jeep has been reliably built this way for more than 20 years. There is nothing "poorly planned" or "mickey mouse" about it. I can assure you that the particular build of this CJ7 brings a fun factor to the table that can't be found in any other off-road vehicle. I feel qualified to say that because I also own two other Jeeps built for radical expeditions through the middle of nowhere and a purpose built rock crawler for the really extreme stuff.

    I guess the real problem is that I personally lack the specific knowledge about Ford 5.0 engines necessary to properly diagnose whatever issues need fixing. Of course, that is why I've come here for help. :cool:
    #64
  5. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    I wonder if something in the wiring is causing this issue? Are there any splices to the harness that the TFI module plugs into? Perhaps it's seeing voltage it shoudln't.

    There should be no reason why your TFIs burn out so quickly or overheat to the point they shut the car off.

    My thinking now is that something in the wiring is not correct and potentially incorrectly wired. But you say it ran well for a long time, before such issues began? Has anything changed?
    #65
  6. FoxMustangLvr

    FoxMustangLvr Advanced Member

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    I'm not telling anyone else to do anything. Sorry if your insulted by me calling SOMEBODY ELSES WORK mickey mouse.


    People lie all the time, and you did refer to the guy SELLING you this vehicle as an Idiot and a crackhead.

    With all the mismatched parts, possible 85 block, EFI from 86-87, unknown aftermarket computer, F-150 exhaust manifold on one side and F-250 on the other, partially removed Smog system etc.....

    Would it really be any surprise that the idiot crackhead guy lied to you about it being featured in a magazine and hitting lots of trails? Maybe somebody was a good fabricator but knew nothing about engines & electrical? Maybe it never ran right and he passed it on to you? You said you bought it in 2010 and never really ran right.

    Somebody recently on SN told me to be weary about somebody who is trying to sell you something, they'll tell you anything. So yes, i'd say with a complicated pieced together engine/computer to start over with a JY motor from an explorer so you know where everything came from and that it all works together or maybe that'd take the fun out of it, right?

    You shouldn't ASSUME it ran perfectly. I bet something is mismatched and/or wired incorrectly and that's hard to find especially if you assume they did it correctly from the get go. People on Stangnet have purchased Mustangs before and parts were mismatched and they found that a MAF wasn't calibrated correctly for their injectors, had a computer for an A/T when they had a 5spd, etc.
    Last edited: Mar 5, 2014
    #66
  7. 5.0 CJ-7

    5.0 CJ-7 Member

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    Fair enough...

    Replacing the engine is not an option for me, so I'd like to get this thread back on track. I have a few questions related to post #62.

    1) Is there a way for me to determine if the camshaft is a roller or a flat tappet without tearing into the engine? I ask because I would very much like to replace the entire distributor. Unfortunately I'm not sure if I need one with a cast iron gear or a steel gear.

    (Note: A couple of years ago I had O'Reilly Auto Parts order one of each for me. When we placed the two new distributors on the counter along with my Jeep's distributor it was impossible to see any differences between the gears. I had read plenty of discussions about the cast iron gears looking more rough while the steel gears appear to be more smooth/machined. There are also claims that scratching the gears can help identify them. All I can say is that no amount of visual comparisons and scratching yielded any noticeable differences between the three gears.)

    2) Could a faulty computer quickly kill new parts in a distributor (specifically the TFI module and/or the PIP)?

    3) Is there a way to determine what the computer is even though there are no factory stickers on the case?

    Thank you in advance for the continued help.
    #67
  8. 5.0 CJ-7

    5.0 CJ-7 Member

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    Update 3/5/14

    It's only a small update, but at this point I'll take whatever I can get. Today I was able to complete the test that my friend and I were attempting to do yesterday. I switched the spark plug wires to the non-HO firing order and started the Jeep. I was honestly that surprised that the engine started and idled, but it certainly didn't idle well. It was shaking violently just like most any engine does when the firing order is messed up. I switched back to the HO firing order, and the engine idled much smoother without any shaking.
    #68
  9. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    If anything that gives us strong evidence that it's a NON-HO computer which is using batch fire.

    Any luck on confirming the injectors are the 14# light grey injectors?
    Honestly, I don't know. I only say this because i've never seen such a mix-matched 5.0 setup before. The previous owner did some good stuff, but I think a few things could be improved.

    Obviously I would say here to fix the problem before upgrades. In in terms of upgrades, i would switch to a Mustang 86-88 Speed Density computer system, and 19# injectors, as well as replace the intake manifold and so on. However, really need to ID what you have before plotting that sort of course Of course, more importantly you need to fix the issues at hand.

    1. No. However if it's a later 80's engine good chance it is a roller block. By 1986 pretty much everything was roller. Of course that's an assumption we can't make right now. Only way to really tell is yank the lower intake.

    2.) Yes, if it send voltage to a wire that it shouldn't see it on. The EEC still needs to be identified however.

    3.) Not really. The part numbers you see molded onto the parts are for the connectors, case and other components themselves.
    #69
  10. 5.0 CJ-7

    5.0 CJ-7 Member

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    I did find a chart (click here) with all of Ford's injector part numbers. Regardless of what the last two letters/numbers might be in the partial part number I was able to see, it would seem that you are correct about the injectors being 14#.

    We are on the same page here. I agree with you that there seem to be some areas for improvement. As you said, however, it would be best to fix the current problem(s) first.

    Now I'm even more confused. For whatever reason I have been under the assumption that all HO firing order cams were roller and all flat tappet cams were non-HO firing order. Are you saying that there are both flat tappet cams and roller cams that use the HO firing order?

    Just tell me how to identify it, and I will do it. In a worst case scenario, I am not totally opposed to replacing the EEC if it turns out to be the likely culprit of the repeated ignition system failures. At that point I could also order whatever EEC will be the best match with the components the engine has.
    #70
  11. 5.0 CJ-7

    5.0 CJ-7 Member

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    I forgot to mention that my friend and I were studying the letters and numbers on the block above the starter. I don't know how much this helps, but they appear to be...

    E5AE
    C3B

    ... but they could be...

    E6AE
    C3B

    After the "E" the top of the number is very squared off like a "5" would be, but the bottom of the number looks like a fully closed circle like a "6" would be. I hate the thought of removing the starter to get a closer look, but if the exact year of the block is in any way relevant to figuring things out I will do it.
    #71
  12. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    More than likely it says E5AE. I don't think there was an E6AE block.

    Basically that tells us it's an 1985-later block, and is roller. As to what car...can't say as that block was put in a lot of 5.0;s.
    #72
  13. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    No, you are right. If there is an HO cam in it, it's a roller block. The block part number confirms this.

    IDing the heads and intake manifold would help narrow things down.

    So far:
    1985-later Roller block
    14# injectors

    The heads are probably E6 castings (vs E7 castings on the 87-later 5.0 HO).

    The upper intake is also probably an E6SE casting as well.
    #73
  14. 5.0 CJ-7

    5.0 CJ-7 Member

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    Sweet! Now I can finally order a new distributor instead repeatedly rebuilding the old one. There are absolutely no doubts that I need one with a steel gear, right?

    I will continue to work on getting whatever other casting numbers and part numbers that I can.
    #74
  15. 5.0 CJ-7

    5.0 CJ-7 Member

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    After making my last post it occurred to me that I might be able to identify the heads based on the spark plugs I last purchased. I recall reading several threads in 2011 stating that fancy, expensive spark plugs are a total waste of money in these engines. Typically I would at least spring for the slightly more expensive platinum plugs, but the discussions seemed to indicate that the Autolite copper plugs were the way to go. Based on those threads, I purchased Autolite copper plugs from O'Reilly. I remember having a difficult time figuring out the right part number though. In the end I determined that the Autolite 26 spark plugs most closely matched the spark plugs I had removed from the engine (I can no longer remember what they were).

    Getting to the point: According to O'Reilly's website, the Autolite 26 spark plugs do not fit '84, '86, or '87 Mustang GTs. Does it therefore seem logical to assume that, unless I am using the wrong spark plugs, the block and heads are from an '85 Mustang GT?

    I was somewhat able to position a mirror under the upper intake. I'm not the greatest at reading things both upside down and in reverse image, but I'm fairly sure I saw RFE6SE-9425-????? with CAE9 and the Ford logo below it.
    #75
  16. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    One of your comments was that the engine seems to smooth out as you increase the throttle. That is a clue that you may have a batch fire computer instead of the sequential fire computer used on the 5.0 Mustangs.

    See http://oldfuelinjection.com/?p=17 for a very good listing of the computer catch codes/part numbers.

    The code 14 is quite possibly the cause of the short TFI life span. It is also possible that the TFI module and computer are a mismatch.

    diagram courtesy of Tmoss & Stang&2Birds
    [​IMG]

    [​IMG]
    Last edited: Mar 8, 2014
    #76
  17. 5.0 CJ-7

    5.0 CJ-7 Member

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    I had a very hectic week, so I apologize for falling behind on providing updates to this thread.

    Here is a quick summary of the past week:

    -- A new Richporter Technology distributor seemed to fix almost all of the problems I was having with the engine. It was amazing!
    -- After a few days of enjoying the Jeep, it again runs poorly with a code 14 (PIP circuit failure) rearing its ugly head again.
    -- For the first time ever I got a code 22 (MAP sensor out of range).
    -- There seems to be an unknown issue with the charging system.

    I will post the full details and some of the stories that go with them a little later.
    #77
  18. Micheal Nadeau

    Micheal Nadeau New Member

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    How does the jeep run when it is first started after sitting for more than two hours? My 89 was acting just like this. Started and ran fine, drove 27 miles to work. By the time I got there, it was kinda sluggish. Shut it off, would not start back. In my attempt to repair neglected wiring , I burnt the signal return (pin 46) trace wire in the pcm. Took me 2 weeks to realize it. Replaced the coil, plugs, wires, distributor, tfi, i.a.c., tps and ignition switch. Before research led me to the signal return. Signal return is a 5v return line. If by chance a 12v source entered the return signal, it can fry that line. The chances that you have had that many TFI failures is unlikely.
    #78
  19. Micheal Nadeau

    Micheal Nadeau New Member

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    You (in problem #5) eluded to what I described above. Also, ford had different O2 wiring harnesses for automatic and manual, and there were differences by year as well, it is possible that someone replaced the O2 harness with one for an automatic, and the wiring crossed (buddy had long tube headers in a C4 car, got an "extended harness" which was meant for a manual, put 12v to his signal return and had the same issues I did.) I didn't mention earlier, the reason this screws everything up, all of your sensors are sending back the difference from 5v to the pcm. With the trace burnt, it does not see that the tps is only at, say 1.3 v. So it assumes everything is at 5v (Wide Open Throttle) So it, after it warms up, you have surging idle (tps actual voltage is not seen) you are fuel fouling (Wide Open Throttle fuel control) and your TFI is working in overload, countering what the computer is sending it trying to control timing for WOT vs what its actally senses (your PIP error)
    #79

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