How can I know if ECA is causing driveability problems and if it is in limp-in mode? Many of the other system items have neen tested and/or substituted, haven't done much with injectors, though. The truck is an 85 F-150 5.0 EFI AOD W/AC. 150'000 mi. One symptom is a rough/ deteriorating idle at stop lights, usually gets noticeably rougher after about 40 seconds. May get rough enough to very nearly stall, and just when you think your'e going to have to put in in park and restart it, it will shudder very harshly and then straighten out to a very "improved" idle state, all this happens with me not doing any thing with acc. pedal. It nearly always will get rougher after @ 40 sec idling, but the roughest/ near-stalling thing only occurs about 3 or 4 times a year now. On only one, isolated occasion, it assumed a kind'a fixed fast idle of about 2K as I exited an interstate ramp. As I recall, it did some very harsh shifting up and down on that ramp and I continued to my destination about 2 mi down the road. It would not slow down from the 2K mark, even when I went under the hood to see that the throttle lever was indeed on the stop. Wiggling/tapping/"bipping" throttle did nothing, nor did any wire jostling or tapping on the TSP & BYP Valve. I Shut it off in gear and hoped for the best. When I restarted it about @ 1/2 hr later, it was back to its old "self" again,(Good thing as I was unusually far from home;Conneaut, Ohio),and it never did anything like that again. Codes were checked within 24 hrs,(@ 6 starts later),NO CODES. On rare occasions it WILL stall. Just as often as not, that happens without notice upon stops and sometimes during shift-changes when parking. And it has deteriorated to stall at lights, too. It NEVER idles or runs smooth; hasn't for longer than I care to remember. It always restarts readily and usually with an idle better than when it stalled. I have even sat in parking spot, in "D" and observed its erratic behavior for a minute or two, finally I'd turn it off and restart it and sure enough it would seem to have "reset" itself, with an improved, but still never smooth idle. Naturally it seems short on power. It is very reliable, though; I have known it like this for about 40k/8years.(The only time it really was unuseable was when the pressure regulator was failing, and it would sometimes stall at slow speed and eventually wouldn't run right at all) Original owner says it was jerked-up from early on, and when he took it back under warranty, Ford allegedly replaced ECA w/ several different updated ones, with mixed/unsatisfactory results, he assures me, it was never close to how it was when it was new, and just seemed to have a mind of its own. Ford said they were doing what they could/should and eventually, the warranty was up, and it still not right. They told him it had a California calibration and that it was partly accountable for the trouble, but all he really knew was that the rascal just never performed nearly as well as when it was new. When I was chatting with the original owner, the better idle after "shutting-down-and-restarting" came up. He said he had noticed that, too, and would do that in traffic sometimes to make it "straighten-out". He had two failures that required tow-ins to the dealer, one in and one out of warranty, I believe. Something leaked a lot of fuel atop the engine when it stopped running one time, but "Fuel-Pressure-Regulator" didn't seem to ring a bell with him; maybe something on the fuel rail.The other was TFI and "pick-up" failure;(which got the deteriorated "pick-up-connector" out of the distributor, anyway.) At different times, I would delve into it, But never really found anything out of order. Compression, Oil Control, Timing Components, are all very good. I have never found any vacuum leaks, anywhere. Does not look like converter is plugged up, according to manifold vacuum tests. Fuel pressure OK. Voltage OK. Grounds looked ok, but I cleaned and tightened them anyway. Relocated CB wiring away from ECA area,(The Ford manual said it could be an RF interference thing) It adjusts speed to carry A/C and gear engagements. Did clean Bypass valve/ throttle body coking and that improved throttle response from standing start some, but that was never unacceptable, anyway. It is capable of setting codes but has never set anything unusual.(Just a pip signal failure, too cold, or forgot to goose, and those were explainable, after timing cks, insufficient warm up or failure to goose.)Did get a 41 one time, but it wouldn't repeat. Bench test showed a "slow to zero", or the like, on ego, so I replaced it, and noticed a very slight improvement in cold idle/ driveoff. Temporarily blanked the EGR to no avail. Went through tests for electrical vacuum controls located near battery, they all did what they should. Out on the highway, you can get used to it, and it cruises along pretty well, but is never smooth-running, and is gutless on grades. Any insight will be appreciated. I see a TSB alluding to electric fuel pump needing filter/choke in power line to eliminate interference in radio,(of which I get some on AM & CB), Anybody know if that Interference would
have effect on ECA,( Ford said a CB may), just a thought.
BVM

 

Do this, while idling, unplug the electrical connection for the MAP, that will put it in limp mode,and, if your idle clears up (it will idle faster,but it should be smooth) , you have a bad MAP sensor. If the idle does not change,you will have to get further into why the PCM did not respond to the MAP being unplugged.
Phillip

 

OK, I'll try that, thanks for the reply and info.
BVM

 

 

Phillip, I did what you said with the map. Idle dropped about 100rpm at first, with no noticeable change in idle quality. After about 20 sec, a gentle hunting began from about 600 to 800. Seemed like it was going to continue that way, so I reconnected map, and disconnected it again with same result. As expected, a 22 code was set. I checked codes prior to doing the map thing and there was a 14 memory code there. I cleared it before proceeding. Also cleared map code when I was done. A recheck confirmed no codes, hard or mem when I closed hood that day. Two days later, after about 8 starts and 60 mi, I checked codes and had an 18 mem.( kinda expected another 14) Cleared the 18, then with engine idling, I Jiggled/moved wires in area of TFI and coil, trying to effect idle. Nothing I did there changed idle. (I realise I may have to do some harness checks between coil, TFI, and "ECA", but It seems finding fault there is unlikely, since code setting seems kinda erratic and the wiggling didn't set any codes.) Immediately after that, a code check showed "none". After another couple days of operation, no codes have been set,(I checked each day.) Still same condition as before, and stumbled leaving stop light on recent trip. I do have another condition which I think "might" be related.(Since the engine's "unsmooth" operation kind'a puts me to mind of how one might run with timing off a bit.) On a warm restart, it, "sometimes", cranks slow & "stiff" at first, then kinda' frees up and cranks OK and starts. It may do this in cool weather, or warm. This began about one year ago. I checked all the usually suspected electrical connections, except for excess power loss through starter relay.( Not sure how to do that right now.) I had auto parts place test battery, and then I replaced starter. Still does it; new starter has been in place for about 10 mo. Reminds me of something with timing out of whack when it does that, or an overheated engine, or an old 396 or the like. I guess I should look at starter draw; I'll need to read up on that, too.
By the way, for what its worth, I swapped in a rebuilt long block in 12-99 and all these symptoms are still the same. If not for the absence of wrist pin noise, you would never know it had been changed. As stated in previous message, the old motor was in great shape, but then developed some pin noise in addition to what I thought was that characteristic bottom end noise some of these motors have. Strangely enough, It still makes some bottom end type noise.
Hard to believe any fresh rebuilt one would have same noise as a 150K one, so I am wondering if the converter or some other transmission item is the source of the noise. Flywheel, or "flex-plate", looked ok when I had it out, and it didn't sound cracked or anything when I "rang" it.
I did notice the bolts that hold it to crankshaft were polished from contact with the convertor. I thought that was strange, noted it, and just put it back together. Torqued the nuts, w/a dab of loc-tite on threads, and rechecked them at about 800 mi. A ex-Ford transmission man told me that happened because, and when, the convertor
swells up a bit. He said while it doesn't necessarily mean the convertor is faulty, nearly all the convertors he replaced had polished those crank bolts. I believe he said the lock-up clutch surface is inside front face of convertor and as clutch failure began, the heat would cause bulging. I really don't think I have the lock-up system and didn't see any "red" debris in trans pan when doing filter there in fall 99. Fact is, mine HAS made contact with crank bolts. And, I see a bulletin about convertor/bolt-head-contact and resulting noise, at this site's TSB lists. Haven't seen actual bulletin yet, but looks like their fix is shorter-headed bolts. I do have noise, It has made contact, and I wouldn't be surprised to learn the convertor is not doing all it should performance-wise. Any suggestions will be appreciated. Phillip, I am curious as to what you think about map disconnection not yeilding faster idle. If I understand your message, an increase in RPM was expected, and it should have smoothed-up. I just didn't see any provision in message for "slower" idle. Thanks again for the help and interest. BVM

 

Well, the main thing is that there was a change in idle quality,therefore, the current MAP sensor was outputting something to the PCM. Two more things I'll suggest, for the constant memory codes you were getting, I recommend redoing the small ground wires incorporated into the negative cable post at the battery. These are often overlooked and have been known to cause "stupid 'lil problems" . Also, if you can afford it, or, if you have another FORD vehicle,try swapping out the MAP sensor to verify the originals operation. As far the torque converter issue, I can understand the problem clearly, but don't seem to think you should worry about it.
Phillip

 

OK. Thanks for the suggestions. Think I'll try them tommorrow. Those small grounds at battery haven't been given any attention in the last 8 years; certainly worth a try. As for swapping in a different Map, well, I will certainly try that, too. I believe the parts store still allows returns on them. Today the truck exhibited yet another of its behaviors; this one never occured very often in the past, maybe 4 times a year. Today it happened on approx 6 of 9 warm start-ups. Started readily each time, (and the "stiff-cranking" business was almost non-existant, by the way)(90-some deg.F here today), then as usual, right after it started, the speed increased to somewhere above idle speed for a few seconds and then tappered back down nicely, "TOWARDS" normal idle speed. But it just continued on down and stalled. On restarts, immediately after those stalls, it did what it usaully does; flared up a bit and settled back down to normal idle speed. (Never stalled on any of those restarts.)
One time it "almost" stalled as above, but then did the old "shuddering real bad thing", and "caught" itself, settling immediately on a more steady idle than usual. On another start, I predicted it would stall, and it seemed like it was going to, but I feathered into it with the accelerator and caught it. Often seems like there's a lack of a smooth transition between the start-up "flare" and idle. Many times after the start up "flare", rpm will drop a bit below idle, then get "caught" and assume idle normal idle speed. When that happens, it is not a badly shuddering transition but isn't very well faired-in either, kinda' like whatever's "catching" it is doing so a bit late. No Codes set during these latest episodes. I have wondered, and hopefully you will know: should it "flare" up past idle rpm at all on warm/hot restarts? If I were not exposed to a small fleet of 93 & or 95 F-350s w/351s, I probably wouldn't question the flaring. Those trucks don't flare like mine does. Its like they fire and immediately adjust "UP" to, and lock-in-on, a good, firm, smooth idle. I'm aware those trucks may have a considerably different set-up than mine. Gosh, maybe they are even "sequentialy" injected. Don't know how much that would change things like this.

 

It might also be time to re-clean the throotle body. I always scrub the throttle body,with a brush of some sort (toothbrush is the best) in order to get the throttle plate area,including the edges of the throttle plate rid of any gunk that may be present. Spraying cleaner alone just doesn't do the trick most times. You need the brush to scrub away the ridge of gunk that is present. Also,remove the air bypass valve assy. for a thourough scrub/cleanibg as well. While you have the bypass unplugged, place an ohmmeter across it and you should get a low reading, like about 10 ohms. In a way, I'm glad the ground wires haven't been attended to lately because I can just about bet that's where the problem is. The battery acis migrates into that connection and makes a very high resistance point,but just enough for a connection,yet not correct.
Phillip

 

Yes, I agree, the bypass has not been cleaned for quite some time, probably almost two years. It was replaced then at the suggestion of a technician who came up with no other answers after scanning with a very elaborate hand-held scanner and found no vac leaks using his choice or aerosol spray around likely places.(No positive results with that new part installed, either, in fact, truck shut-off while coasting into a parking area just 6 mi later. No codes set then, and no routine of frequent stalls was established then either, "life" just went on as usual, very reliable but it was still jerked-up.)Throttle body bores are due for cleaning also. I choose to remove the whole business and clean it on bench with TPS removed. Was informed that TPS could be damaged by cleaners, so I don't take chances with it. By the way, some time ago I was looking at tech articles in Mustangs & Fords type magazine, and a guy had written in asking for advice on a persistant idle/driveability problem. His conditon seemed to persist in spite of the fact he had tried alot of the "standard" fixes. Tech advisor told him to adjust his TSP to a specified, closed throttle voltage; a voltage other than the one Ford specified for his particular model.I believe the spec given the guy was higher than Ford's. Mine is considered non-adjustable, but will yield a bit of adj. I'm quite sure holes could be elongated a bit to allow for some more adj. I never looked into it any further. Just wondered if you had ever heard of such a thing. Mine is where my Ford manual "wants" it. I believe the guy who wrote to the magazine had totally stock system.

On grounds:: I checked several wires/connections w/ohm meter, after isolating them. There is only one "AT" battery, and it is spliced to the main cable about 8" from battery, then about 6" beyond that is a disconnect point for that small wire. Disconnected neg term at battery, and the small wire's plug. Monitored circuit from battery clamp to the "battery" side of the small wire's connector, with ohm meter, while wiggling & twisting, etc. Found no fault there. I did not open the wire to visually inspect the splice. I guess I should have, right? I might have, but got sidetracked tracing rest of that small wire's route. I spent a lot of time figuring out where 7 other grounds went. 5 of those are spliced to that "Main" small one; right at the point where the engine's harness goes thru firewall. The spliced area is actually partially in firewall grommet. 1 of those 5 is also comming from engine compartment, though I didn't have time to find where from. The other 4 in that 6-wire-splice went to cab: 2 to ECA; 1 is terminated about 12" into cab, & the other one goes into the unit which appears to be "piggybacked" onto ECA.(Cruise Control?) Yeah, THE TERMINATED ONE ??? It is cut, the end tapped, and the wire itself tapped to another wire. I only made notes on this stuff today, (time limitations), and will try to see where those in question go. I have the prints, and frankly, I know from experience, it "can" take "me" a while to get the hang of sucessfully reading them. I just didn't want to spend time trying to read them "under-the-gun". I had stuff pretty well "disturbed" around distributer/bypass valve/coil area, and didn't want to have to rush getting that area groomed and "chafe-proofed". Of those other two grounds, not involved in the 6-way-splice, one goes from block to wiper motor mount, another from block meets two more in disconnect near firewall,(as I recall, one of those two is the "shielding" wire that spirals around the "TFI-to-ECA" wires, and the other went to ECA. Anyway, those all looked ok, and those I metered checked ok. I did not disconnect ECA to isolate those connected to it. I understand that should be done, but another day. The six-way-splice looked ok, for what that's worth.

The 3-way splice near distributor, for bypass valve operation, that was one I felt warranted re-doing. It is now re-done quite well. It also ohm-checked ok prior to rework.

Also scrutinzed primary connections at coil with meter. Tested ok that way, but they aren't very pretty.

Truck still acts same. Wiggled lots of wiring while at curb and idle and warmed up. Wiggled stuff at ECA, firewall penetration, and around dist/byp/tps. No change in idle. Did not check for codes.

You think its normal for this thing to idle at @1700 for about 1 min when
fired "cold", at about 85 deg F ambient. Always has, and will decrease if you tap throttle after it has established the 1700.

Did not get to try map sensor, but will.

I went to try to get a van running better this eve. Put plugs in it on a hunch. It had sat two years and starts pretty willingly, but will just barely idle, and is horribly rough running, and has no power. I have it on good authority that it ran ok when parked. Plugs made almost no difference. Looked for rodent-chewed wires or hoses, but saw none. Engine is very orderly looking,( no mouse nests or obvious jury rigs or plugged off hoses, etc.) I am suspecting fuel problems. Have "added" ten gallons of fresh gas and a can of inj cleaner, ran it some after that to get that circulated around some,(that was Saturday afternoon, so that "soaked" overnight.)

It will not hold a steady speed,(in park), for very long. If I hold throttle at a fixed position, say about 1500, it will begin to slow and roughen-up and almost die, then shudder and make pre-ignition/detonation noise,(pretty severe), (sometimes this almost sounds like dieseling or run-on.) You can catch it with throtle, and can keep it running fairly steady by constantly tweaking throttle. It will rev up, but not readily. Assuming it is a fuel problem, I guess I'll have to try to physically clean the throttle-body. It is an 86 GM 4.3, throttle-body-injected. I've no experience here. Plan to read codes next visit. Got any ideas? Can we discuss this here, or gotta do it another way.
I didn't find a GM forum last night. You know of any? This Ford one was certainly easier for me to locate than what they may have. Thanks again BVM