SavaG35

96 5.0
When it is warm the truck starts, runs decent but misses still, usually way worse under load.
When it is below like 40 the truck either will not start or will idle rough to the point its choppy and throws fireballs until it reaches ECT reading of 120 where it calms down to a smooth 750 rpm (closed loop?). Truck has no cats and straight piped leaking exhaust (previous owner). I have cleaned IAC and set timing to 12 BTDC with light, passed noid light test so I believe that means PIP is good.
MAF registers 0.02lb/s
TPS range 1.02v-4.7v (20.4%-92%)
ECT runs about 172 at idle
Fuel pressure KOEO 40 psi
Compression about 150 all around.
long term fuel trims are always negative, short term some how spiked to 90 when on a cold start idle but stay below 20 once warm.
replaced: plugs, wires, cap, rotor, fuel pum, PCV, fuel filter, vacuum lines, battery is fairly new, IAC is fairly new.
codes: 320, 385, 172, 175, 133, 136, 141

I am lost where to go next. It seems to me the truck is struggling when rpm are or should be higher, such as the open loop needed to start on cold days, or it cuts out when I rev in park.

wde3477

Welcome to the site!
One quick-n-easy suggestion to see whether anything changes is to roll the key to On a couple of times before going on to Start. Giving it a couple extra fuel priming cycles made all the difference in getting my '89 going and staying running in cold weather on a cold engine, never got ambitious enough to figure out why.

SavaG35

Hey thanks for the insight but I am actually getting too much fuel I believe. it backfires

raski

Pull the negative off the battery for a while and see what code(s) resurface and go from there. May want to pull the vacuum line off the fuel regulator and look/smell for raw gas getting sucked into manifold. You are getting a couple o2 codes but that may be a symptom of the problem since they do not have anything to do with a cold engine in open loop.

SavaG35

Thanks for the suggestions, there isnt any fuel in the vacuum lines to the FPR

Steve83

That's not much of a description. Click this, read the caption, and fill in your signature:


(phone app link)The engine, or the weather?From where? Tailpipe, intake, or somewhere else?Ohms, degrees, or something else? Every number needs units.Well, that's probably a BIG factor... At the very least, you need to fix the leaks before any other diagnosis. But you should really put good cats back on it, if you want it to run right & be legal.You cleaned a new IAC? How exactly?It belongs at 10°BTDC.How exactly did you use a noid light to test what exactly?The only way to confirm that is to follow the ignition diagnostic procedure in this caption:


(phone app link)Under what conditions? What RPM & ACT?That's not how the TPS is tested.


(phone app link)What about KOER @idle & @WOT?That's not a compression test.


(phone app link)For EACH one: why? What diagnostic step did it fail? Did the replacement pass the same test? What brand/PN/source is each replacement?We don't have the numbers & definitions memorized. For each code number, include its FULL definition:


(phone app link)Pick ONE symptom, and diagnose it until you positively ID the fault. Repair it (which does NOT necessarily mean replacing any part) and start over checking for symptoms. Some might have been coincidentally repaired. If you don't have a Haynes manual, get one as this caption describes:


(phone app link)

When you have one, read it cover-to-cover at least once so you know what's in it & where to find things.The EEC always wakes up in open-loop (every time it powers on). Even if the HEGO is already hot enough to work, the EEC will not enter closed-loop for ~1min.Why are you revving in park? How high RPM?

raski

You mentioned " ECT runs about 172 at idle ", what temperature is the sensor sending when cold? Being a 96, that should be an OBD2 system. If so, connect a scan tool and see what parameters are being indicated when problem occurs. You need to gather some information so you can logically troubleshoot the issue w/o buying a bag of parts and start guessing.

SavaG35

Finally I can get some real information, I am *clearly* new at this, so thank you for being the one to take the time to get me up to speed.
Both, it does not start when cold so the engine cannot get hot and the weather be cold, fireball is tailpipe, ECT is in degrees (also new), the exhaust sucks but I want to track down the cold starting misfiring issues first if that is realistic, the IAC I can assume is newer because of appearance but I cleaned be removing and spraying with carb cleaner, it is set to 10 BTDC now (it is warm enough to run), noid light was on injector wiring for pulse, PIP is also new and OEM
MAF reading is at the idle 650-800 and ACT is whatever the temp is outside, today was 48, I had another ford tech tell me to measure TPS voltage so that is how it was tested.
I could not do that since the truck did not run, I do not have the equipment for a full on compression test, I worked with what I had
parts were all motorcraft, some dealer, some rockauto, some oreillys, some advanced auto
fuel pump was autozone, not motorcraft
they were mostly because I wanted to tune up.
Right now code is p0320 ignition speed input circuit
ok I need to work with the p0320
to hear it cut out, it varies ofcourse, roughly 3k

I think I formatted right, if it is weird I will be editing and fixing if i can

sdmartin65

Steve is correct about picking a fault code, solving for it, then moving to next code if it still exists. With one caveat for the OBD2 and that is to solve the first code in sequence. In this case hopefully the PO320 is the first code. This code indicates a problem with the crankshaft sensor located on a bracket on the timing cover. The sensor gets a reading from a ring bolted to the harmonic balancer.

Steve83

Then the engine is running horrifically rich. Not only does that waste gas & potentially start fires; it overheats (ruins) the cats, and dilutes the engine oil damaging the rings & bearings, and produces LOTS of HC & CO pollution (much of which passes through the cab & your lungs, but also everyone else's).You should edit that into your original post, too.There's no reason to think the exhaust leak is NOT related to the other symptoms, and several reasons to think it IS. Fix it. At least temporarily - weld or putty up the leaks, if only those FORWARD of the muffler.Not really. Someone might have cleaned it. YOU did... Maybe someone before you did, too. This one is 22 years old:


(phone app link)

But I only cleaned its OUTside.To avoid ruining it (which you or the person who cleaned it before you might have already done), the procedure in this caption must be followed:


(phone app link)Why? When? What test did the previous one fail? Did the new one pass the same test?

"OEM" means "original equipment MANUFACTURER" (the company that made the original). Do you know what company made the original PIP? If you're talking about a MotorCraft BRAND part, that's just a BRAND (a label). MC doesn't actually make ANY parts. It's a licensing company that handles specifications & standards for Ford-designed parts. (BTW Ford also manufactures NO parts.) There might be 20 manufacturers of MC parts, and it's possible that the OE (assembly-line) parts were made by 1 or 20 DIFFERENT manufacturers than those who make MC brand.No, the ACT reading WHEN you got that MAF reading.It is tested by its voltage. But not by measuring a single voltage - you have to observe the CHANGE in voltage relative to TPS angle, as the caption of that diagram explains.If you measured compression pressure, that's all the equipment. Read that caption.We don't need to know about "all" the parts; we need to know about EACH part. One at a time - all its details & reasons. Then the next...See? Not "all". And zone parts are garbage, even if they're the same BRAND as you find from other suppliers. Return any zone parts you can, and then stay away from there.EFIs don't need tune-ups; they tune themselves ~200x per second. They only need maintenance (according to the published schedule) & repairs for identifiable & diagnosable faults. Messing with a 20-year-old vehicle unnecessarily is more likely to CAUSE problems than to prevent any.That's not a complete definition, or even an accurate one. There is no such thing as "ignition speed". But assuming there was; the vehicle would have come from the factory with an "ignition speed input circuit", so having it now wouldn't be a fault.You might rev it to 7K to hear a rod come through the block. But it wouldn't be good for you or the engine, so don't. The highest it needs to rev in P or N is ~2500 for a few very-specific tests & procedures, which you'll probably never need to do. Some EECs have over-rev protection built in, so it's possible that the cutting out you triggered was just to keep the rods inside.No, it doesn't, and that's not a crankshaft position sensor. It's a misfire sensor, which is only used for emissions diagnosis. P0320 (in the context of this truck) refers strictly to the PIP.