Spark Plug Missing?

[TucsonSHO]

Hey guys, I'm really about to hang myself here. I've had this missing for a little over a month now. It's usually a hesitation below 3500 rpms or so, also evident with hard starts. I installed a walbro fuel pump last week, despite my pressure appearing to be ok. The wires are OEM motorcraft(with 10-15k on them). I put in the Motorcraft plugs which came all gapped to .045" on sunday and the missing ceased for about 48 hours, or maybe 20 miles at most. Previous to the motorcraft plugs i had put in denso's about a month ago. The problem was better then, but not totally gone as with the motorcraft plugs. The denso's seemed to help for about 2 days. Bad piston ring letting oil in there? I can't see any oil accumulation in the wells, or moisture for that matter. When I put in the motorcraft plugs i cleaned the wires with electrical cleaner and the coated the conductors with di-electric grease. The only visible spark plug condition i can see is the red coating from fuel additives i suppose. Coil packs? DIS? Wires again? Any and all suggestions would be greatly apreciated-

Clovis

 

[RStalveyARFF]

run your codes, and run a cylinder balance test. Then post back with what you find and we can move on from there.

 

[sdpatt]

You seem to be up on taking care of the SHO engine, but just in case you haven't "pulled the EEC codes," you can click on the links at the bottom of my signature to learn how. It takes no tools or electrical devices other than a short jumper wire and is a great tool itself to help diagnose engine control problems.

 

[SonicRiot]

Check the module for brittle plastic parts and the distributor for faults. We had an 85 LTD in the shop at school. The module under the distributor was old, brittle plastic. IT was causing problems with missing...until I knocked it off with a wrench while I was doing a t-stat! oh Now it doesn't run at all!

 

[TucsonSHO]

Hey guys, I pulled my codes a month ago when i was having the same problem, and ran the cylinder balance test. The cylinder balance test revealed nothing, and the codes pointed to my fuel pump and o2 sensors, which since then have been replaced. No more ce lights since then, but i guess i could try for the **** of it.

About 2-3 months ago my old engine's crankshaft sprocket stripped out and ******** my timing all aledgedly due to a messed up harmonic balancer. Seemed easier to get a replacement engine than a crankshaft, get it balanced, and rebuild everything. So i got an engine fomr al fitz at midwest, and after the install we were all good for about 5 weeks or so. when the engine went in many gaskets were changed, belts, water pump, and a bunch of other stuff i can't remember right now. I have ted breauxs chip in there sometimes, although not for a while now just trying to narrow this down. I have hollowed out cats, other misc exhaust leaks, a c&l maf, and a k&n panel. Other than that it's all basically bone stock.

Anyways, guess i'm going to go look at those plugs again and se what i can find, probably check for codes too. Keep the ideas coming! I'm desperate and running out of money fast!

Clovis

 

[TucsonSHO]

By the way, it's a 92 mtx with 112k, roughly 80k on the used engine. what plastic module is that you suspect may be brittle?? Something for the coil packs?

I also get this hideous squeking occaisonally when i fire it up, pretty sure it's just a semi-dry belt. A little shot of armor all seems to help, not sure if thats related at all. Still had it when the missing subsided for 2 days with the installation of the motorcraft plugs.

Clovis

 

[TucsonSHO]

I'm really starting to think that it is something to do with oil in the cylinder. I think the hesitation returned slightly after adding a quart of oil when i noticed it was below the add a qurt line. I went and pulled my plugs out today and regapped them to .043" . In doing so I discovered the spark plug to the center cylinder in the front bank had some black deposits on it like the rest of the plugs, but also had a little sheen to it (kinda wet looking). Upon further inspection i realized that the ceramic near the top of the plug, where the boot covers, was cracked. To small fine cracks on either side going vertically. I looked for a diagnosis on such a plug condition without much luck, maybe pre-ignition, oil splashing in due to worn valve guide or piston ring, i don't know really. Anyways, I went out and bought another agsp-32pp motorcraft plug and put it in hoping that the one was defective and not a symptom of worse things to come, reset the cpu and dropped the chip back in, but it did nothing for me. Maybe my dipsticks off and the engine has too much oil? It seems to consume a quart every 150-200 miles or so, but i never see it leaking out. Anyone know of a "hotter" plug for the sho? That might do it for me. In the meantime i'm going to check grounds and get those codes if there are any.

Thanks in advance for the advice-

Clovis

 

[munkee]

Sonicriots advice is pretty good, just not for the sho which doesn't have a distributor. Make sure the other plugs aren't broken if you haven't already. I broke one last year when I was having some problems and was removing the plugs a lot. Have you had this problem since the replacement motor was installed? Sounds like a lot of oil usage for the mileage to me. You might try a compression test to see if you have a bad cylinder. Does anyone know if a slightly misgapped cps could cause this sort of problem, or would it be much worse? Hope you get it figured out.

 

[TucsonSHO]

The replacement motor was installed and i had no problems for about 4-5 weeks. I pulled all the plugs today and only the one was visably damaged in any way. I just checked all the grounds i could find, and made a few of my own to no avail. The car does zap me usually when i get out, so i probably have some issue there. I've also checked all the electrical connectors i can find. Next Codes and wire resistance i suppose. 8000 ohms per foot is it?

 

[TucsonSHO]

ok so koeo i got:

511 -i think is my chip (forgot to take it out)
519 -maybe my power steering pump is bad? A friend told me my ps fluid was burnt, could that cause so much hesitation? I do have that squeeking.....

koer i got:

521 - I don't think i turned the whell at the right time..
536 - Same w/ the brake oh

cylinder balance test yielded nothing (9) although the misses are intermittent and definately not steady at 1500 rpms w/ no load

Still lost here-
Clovis

 

[AutoSHO]

I, unfortunately, am chasing exactly the same problem with my car. The only things I have left to replace that may be causing it for me are: Timing Belt, Timing Chain Tensioners, and CPS.

Every other sensor has been replaced. The only thing that I can figure other than that is that I've got a warped valve or something. My car uses little to no oil, and only hesitates below 2k rpms, sounding like it loses 1-3 cylinders, bogs and hesitates badly. At higher RPMs (up to about 3k) it it just an intermittant bucking. Mine also disappeared for a drive when I replaced the plugs. Came back the next day, about 20 miles later. I am gonna be doing a complete 60k in a week and a half... I will report you my findings then.

 

[TucsonSHO]

Hey, i just did the tests again w/out the chip after resetting:

engine off-
528 maybe i accidentally hit the clutch? ac wasn't on...
519 time for a new pump and or sensor?

engine on-
521 again, i know i turned the wheel far enough and fast enough...

Could the power steering pump and or switch make the engine miss so much?

Clovis

 

[projectSHO89]

None of those codes are likely indicative of problems that would cause either your symptoms or are of particular immediate concern.

If you can try running the CBT while the engine isacting up, you might find something of interest.

If there were oil contaminating a plug, you would have seen the residue when you pulled the plug out for replacement or inspection.

My suspicion is that your problem is going to be found to be an intermittent plug wire, coil pack, DIS, intake crossover grounding issue, or injector-related problem.

This is a time when a shop scope would come in handy so you could "see" the ignition system in action.

Steve

 

[AutoSHO]

projectSHO89:
My suspicion is that your problem is going to be found to be an intermittent plug wire, coil pack, DIS, intake crossover grounding issue, or injector-related problem.

Steve, suppose someone had already changed all of the above (to no avail) along with every other engine sensor aside from the CPS. Is it feasible that the CPS could caus a problem like this? What about a stretched timing belt?

I've replaced every engine sensor aside from the CPS, 3 computers, swapped engine wiring harnesses, replaced the FPR and Fuel filter (pressure acts perfect and jumps immediately upon opening the throttle) and the car spits no codes. Its very frustrating!

 

[TucsonSHO]

Hey autosho, you replaced your injectors? Or at least had them balanced and cleaned? That was hoing to be one of my next plans of action. First i think i'm going to check my timing and look for proper tension in the belt, then probably get a shop to analyse my ignition as suggested.

It's really odd how the new plugs cure it for about 20 miles or so though.......

Clovis

 

[Off Road SHO]

It's really odd how the new plugs cure it for about 20 miles or so though.......

Clovis [/QB][/QUOTE]


This is interesting. It sounds like the engine runs better when it's cold. Is that true?

Have you run out of gas lately or had the gas tank sitting partially full for a long period of time? If so, you might have a clogged injector from condensation.

Flush the system by removing the return fuel line at the crossover plenum and putting a large hose over the flared metal ******. REMEMBER, the gas will come OUT of the engine when the return is disconnected. (Don't ask me how I know that). Cycle the key to make like you want to start but only turn it enough to get the three seconds of pre-pressurization. Collect the fuel in a clean coffee can so you can see if it is made up of one layer (that would be good) or two layers, one of gas on top and water underneath.

If you do get two layers, just keep pumping until you get just gas. At this point re-attach the return line and put in a new fuel filter.

Put a bottle of gas treatment in a 1/2 tank (8 gallons) of gas and run it. When water gets in the tank, even though it doesn't mix well with gasoline, it does cause the gas to gel a little at the interface.

HTH

Tom

 

[AutoSHO]

Clovis:
Hey autosho, you replaced your injectors? Or at least had them balanced and cleaned? That was hoing to be one of my next plans of action. First i think i'm going to check my timing and look for proper tension in the belt, then probably get a shop to analyse my ignition as suggested.

It's really odd how the new plugs cure it for about 20 miles or so though.......

Clovis

Yup, put in a fresh set of injectors to no avail. I find it exceptionally unusual that plugs fix it, just for a little while. I sure hope the CPS/Timing Belt fixes it. If not, look for a 92 in the classifieds.

 

[SonicRiot]

also get this hideous squeking occaisonally when i fire it up, pretty sure it's just a semi-dry belt. A little shot of armor all seems to help, not sure if thats related at all.

That means you need a belt replacement. Stop using armor all on it! Don't you know that stuff ruins rubber with time?!

BUT, is the squeak more of a groan? If so, it may be coming from you PSP...change the fluid first to see if that remedies it at all. Just remember...it's a Fords, so all the power steering pumps squeak to a point, especially when cold.

Oh, and about the SHO not having a distributor... slap ...wasn't thinking. But still ,check all connections.

EDIT: BTW, check you rfiring order and make sure your plug wires are in their proper places in the spacers. RFI might be causing your problems...

<small>[ March 04, 2004, 10:30 PM: Message edited by: SonicRiot ]</small>

 

[TucsonSHO]

Thanks for the advice Tom, I'll try that in the morning. By gas treatment do you mean something for the injectors or something like "dry gas"? By the way I always drool when I see that sandrail.

My belts are only 2-3k old, new when I replaced the engine. I'll see if there's any slack there tomorrow. Pretty sure my ps fluid is burnt, possibly in need of a purge, gotta change that too.

Keepin my fingers crossed-

Clovis

 

[TucsonSHO]

EUREEKA!!!!!!!!!

I was doing a compression test today when i discovered a small amount of grey residue on one of my boots. Upon closer inspection (suspecting arcing) I noticed the smallest little pinhole. It's located right were the red dot is on the picture. Out of desperation and anxiousness I superglued a small piece of wire insulator on and- TA-DAH!! No more misses. Not sure how long my Ghetto-fix will hold, might be time for new wires. I think i might drill the hole out a little more and fill it with epoxy if the missing returns, unless anyone has any better suggestions on boot repair. Also the bracket to hold my chip in kinda sucks, anyone replace it with a clamp or something from home depot? Thanks again for everyones advice.

Lovin 4k again-

Clovis