pinging and loss of power = me not happy

[Euphoric306]

in the last few weeks ive replaced the dist. cap, plug wires, plugs, and set the timing numerous times... heres my problem:

very noticeable pinging at lower rpms, especially uphill.

when i keep tranny in first and punch it thru 1st its fine, maybe a slight loss of power at different timing adjustments, but on the freeway over 70mph, even cruising at 3000rpm, i can feel the engine struggling to stay at that rpm, and most of the time it will not climb in rpm at WOT, and the rpms will start to drop and will continue to drop until i let off the accel, let the engine rest for a few secs then ease backon slowly. ive ended up at 35mph in the slow lane w/ emergency flashers on a couple times and now im sick of it.

my dad has told me it's probably timing, since the spark is (was) hitting at the corner of the rotor, but ive tried 8° (emissions control label instructions) 10°, 12-14°, and about 16°. all timings have had pinging problems and/or loss of power. im suffering immensley in gas mileage and am running short on funds very quickly. any help would be appreciated.

he's also mentioned it could be the coil, the ignition module, or some other component of the ignition system. ive almost convinced myself its got to do with fuel system or something. ive replaced fuel filter a few weeks ago and used stp injector cleaner after filter r&r. pump engagement sound when car is turned on sounds funny sometimes, but pump hasn't failed at all.

i think ive given all the info thats been racing around my head, anyone had similar problems/experiences??? thanks a million guys, stangnet's been more than helpful in the past.

 

[Euphoric306]

blah

 

[HISSIN50]

no need to wonder - have you pulled codes to see what the puter is saying?

got a FP gauge. might hook it up to see what is happening at the problem RPMs.

sure the plug wires are not mixed up (HO vs non HO firing order)?

ignition stuff can he harder to check out.

good luck.

 

[86/92stang]

blah

Didnt fully read it but my guess would be a dirty maf.

EDIT :Sorry just noticed its not EFI


I also recommend checking fuel pressure. Preferably while driving with another person or on a dyno. Any recent changes? Has it always done this?

 

[HISSIN50]

i read the post half way - can you provide more info on what an 84 has engine management wise? carbed? vac advance dizzy or duraspark, etc.....im not conversant with the older stuff - and if some of the stuff in my first post does not apply, i aplogize.

 

[86/92stang]

i read the post half way - can you provide more info on what an 84 has engine management wise? carbed? vac advance dizzy or duraspark, etc.....im not conversant with the older stuff - and if some of the stuff in my first post does not apply, i aplogize.

LOL yeah i went back and read your post then noticed it was a "stock" 84. There was a "efi" in 84 but it wasnt like it is in the sefi systems. I assume since the pic in his sig is not white w/ red letters its not one. Im not too good with the older stuff either.

 

[Euphoric306]

umm yea there was no efi in 84 it was throttle body injection, cfi, which is what i have.

pulling codes.... thought this was only for later model mustangs... guess i was wrong.

my dad had mentioned fuel pressure check and he brought hope a fp checker so ill be using that.

replaced each wire one at a time, no chance of mix-up. got my haynes manual as well.

as for the dist... from what i understand its a duraspark.

never heard of a white with red letters stang. in 84 there was a white with blue letters "gt350" to honor the shelby gt 350's of the previous years.

eh... all auto stangs in 84/85 came with cfi, 5spds got the carb, 86 all were efi.

as far as recent changes... its been having this problem for a while, just finally got around to doing something about it.

tomorrow ill be checking fuel pressure at all rpms and also looking at my spark to see the quality of it. thanks for the help people, my thanks to you.

another quick question.... is there anything that works a lot harder at 75 mph than at 35 mph (assuming same engine rpm)?? obviously the tires, suspension, etc... im talking about induction, ignition, valvetrain. who knows... maybe ive just got a cracked block or something, haha....

 

[86/92stang]

umm yea there was no efi in 84 it was throttle body injection, cfi, which is what i have.

pulling codes.... thought this was only for later model mustangs... guess i was wrong.

my dad had mentioned fuel pressure check and he brought hope a fp checker so ill be using that.

replaced each wire one at a time, no chance of mix-up. got my haynes manual as well.

as for the dist... from what i understand its a duraspark.

never heard of a white with red letters stang. in 84 there was a white with blue letters "gt350" to honor the shelby gt 350's of the previous years.

eh... all auto stangs in 84/85 came with cfi, 5spds got the carb, 86 all were efi.

as far as recent changes... its been having this problem for a while, just finally got around to doing something about it.

tomorrow ill be checking fuel pressure at all rpms and also looking at my spark to see the quality of it. thanks for the help people, my thanks to you.

another quick question.... is there anything that works a lot harder at 75 mph than at 35 mph (assuming same engine rpm)?? obviously the tires, suspension, etc... im talking about induction, ignition, valvetrain. who knows... maybe ive just got a cracked block or something, haha....

Sorry i thought i hit a "c". I absolutely hate the cfi. I had an issue with an 85 that was a pain. So it is the same as a 85 cfi? I always thought it was red lettering. I know 86 & up, but will help if i can. Also when checking f/p if you can do it under a load. Could it possibly just be too much carbon on the piston tops? Maybe try some GM "top engine cleaner"

 

[Euphoric306]

oh, by the way.... the whole car's only got 125k miles on it, which is nice for a 20 yr old car.... every part ive pulled off the car either says ford motor company or motorcraft on it.... reassuring, yet disheartening, cuz i know all the parts that need replacing r gonna fail at once lol.... not good on the ol' wallet eh....

 

[HISSIN50]

thanks for clarifying the set up on your car. i knew that there were induction differences with Autos vs 5 sp's in that vintage, but i cant keep it straight.

you asked about differences at 75 vs 35 MPH. there is a ton more drag and loss of mechanical advantage from gearing (1st and 2nd have more torque advantage vs 4th or 5th).

it sounds like you are on the right track. i dont know much about Duraspark or CFI so im of no help.

BTW, i would be happy you have so much OEM componentry on the car. you know what you got, as opposed to having something someone hodge podged together. i prefer to see what you got.

it could be something very simple.

good luck to ya, Blah.

 

[Euphoric306]

thanks a lot guys, update goes as follows.... we've fooled around with the timing, fuel pressure is fine, it now does fine at high speeds and rpms but has eratic idle sometimes and when cruising at 25 or 35 it is very rough. while looking at it today, i moved a bunch of wires around the coil and my engine shut off, then i heard the fuel pump click back on.... shows that ive got a loose connection or broken wire, ill be looking for that in the next day or so...


also found out i do not have duraspark ignition, most 83/84's came with dura, but my particular car has TFI-IV, which means that i might need a new ignition module or brain (worst case scenario)

also, my pcv valve is failing, so i plugged off the line at the intake manifold. ive also got a bunch more plugged vaccuum lines i dunno what for.

thanks for your help again, im sure ill have this beast running smooth again in no time (money, however will be spent)

 

[Euphoric306]

oh yes, and i reconnected a wire to the ignition module and that seemed to fix my timing advance problem i was having at high speeds

 

[HISSIN50]

nice work doing a 'goose test' to find some problems. i would make sure you are venting crankcase pressure by some means (breather, new PCV, etc). I'm not sure what you did, but you dont want to plug the crankcase up (i dont think you did that - but im not sure).

good luck.

 

[Euphoric306]

not following the terminology of "goose test," but thanks. the pcv valve in front on the drivers side head is malfunctioning, but still venting so we're good.

im so close to fixing this problem i can smell it... maybe thats just the pcv thats venting into my engine chamber, haha.

by the way, i use this car 5/7 days of the week for delivering pizza (i know, ouch) but im saving up to buy my buddies 94 cavalier... 30 mpg sounds soooo good. anyway, tonight the the problem i described while cruising or accelerating seemed to come and go, so im almost positive its got to do with that loose connection. now i have to wait for some daylight... ugh

 

[HISSIN50]

not following the terminology of "goose test," but thanks. the pcv valve in front on the drivers side head is malfunctioning, but still venting so we're good.

im so close to fixing this problem i can smell it... maybe thats just the pcv thats venting into my engine chamber, haha.

by the way, i use this car 5/7 days of the week for delivering pizza (i know, ouch) but im saving up to buy my buddies 94 cavalier... 30 mpg sounds soooo good. anyway, tonight the the problem i described while cruising or accelerating seemed to come and go, so im almost positive its got to do with that loose connection. now i have to wait for some daylight... ugh

goose or wiggle test is just that. you wiggle wires lookin for poor connections.

how is the PCV malfunctioning? PCV cant vent into the chamber or your crankcase would be filled with massive positive pressure....sorry that i dont understand what you mean.

good luck with it all.

 

[Euphoric306]

hehe im tired and said chamber instead of compartment. not sure how the pcv valve works, but it was making a rattling sound and my dad said it supposed to be shut sometimes or something (maybe im wrong) but its airflow is reduced anyway.... blah.

 

[bt15]

I've experienced similar problems with 1) clogged catalytic convertor(s), 2) failing coils, and 3) failing TFI module. Check for clogged cats by having someone sit behind the car and physically feeling for exhaust coming out of the pipe(s) while revving the car and holding it at speed for a couple of seconds. Check for a failing coil by (duh) replacing it, same for the TFI module. You can do a check on the coil with an ohmmeter, but it's sometimes misleading. Sometimes it shows in spec and doesn't work at temp / speed. The TFI module can also be checked across the contact points, but sometimes you have the same temp / speed problems. Good luck!

 

[Euphoric306]

appreciate it,

remember that wire i reconnected to the module? well down the way a little bit (away from module, obviously) it had a break in it that was all but spent. fixed it up nice, reset the idle, my timing is now at 8° (factory emissions label specs) and it runs smooth.

only problem now is low power in the low rpms (ive had more power before from the car so dont say its cuz my cars slow.... it is slow, but ive had it faster lol).

also, when im in gear at a stoplight or something (aod), engine rpm will oscillate between a very rough ~250 rpm and a nice even 550 rpm. the oscillation is much more consistent than the random surges i was having before (= me happier)

next step i plan on is replacing the coil (i checked the spark with a screwdriver to the fram and it was a pale yellowish orange, id like it to be a nice bright blue again. if that doesnt fix the problem, ill take a trip to the junkyard and find a tfi module (or ill just scrimp for the 77 bucks for a new one) and see if that doesnt help

hopefully this whole ordeal will be over soon. thanks once again for your time/interest

 

[Euphoric306]

urghhhhhh, it indeed has returned... thats right, the surging and rough idle has returned after driving about 50 city miles in one night. i have only to say that it only seems to start when the engine reaches operating tempterature.

cant do anything now, its 1230 in the morning. when i get payed ill probably be putting a whole new ignition system on it... ive already got spark plugs, plug wires, and a distributor cap, now all i need to do is pick up a new coil and ignition modulem. then ill know its not my ign. system going bad.

im starting to greatly dislike this car...








.....not really