Engine stutter after new spark plugs

[Lud1konj]

I need help ...Ford garage told me that i need new leads/cables for my spark plugs. Symptoms inluded stuttering under 2000 rpms while accelerating, sometimes during hard acceleration (under 2000 rpm) the engine "pops" and after that loses power...last symptom occurred a couple of weeks ago, rough idle and a sense that the engine might cut out at any moment (but rpms holding strong at 900)....Since I don't have the amount of money the Ford garage asked for, I decided to go to a friend that works with auto parts. He installed a set of Motorcraft "genuine Ford part" spark plugs (the old ones were in a pretty bad shape) and he installed leads. Then I went for a test drive and my Puma seemed to struggle even more. Not only under 2000 rpm but over the whole rev band I went back and we concluded that the leads were not the correct ones (they seem thinner than the ones i had on), so he put back on the old ones and ordered another set (they will be here in two weeks). After another test drive (with the new spark plugs and my old leads) it was still stuttering during acceleration (give it 1/4 acceleration or full acceleration, at any rpm, makes no difference, it stutters and lags, sometimes pops during low rpm) and rough idling but this time the rpms vary between 700 and 900. The engine hasn't cut out at any point, but it still gives you a sense that it might quit at any time

I remember him saying that the NGK spark plugs are platinum and these Motorcraft aren't. I'm not a mechanic so I ask you, does that make a huge difference for our Pumas or was this just the tip of the iceberg and there's something else causing these problems? I'm pretty freaked cause I currently don't have a job and can't pay for any major repairs so good news like "wrong spark plugs" would be excellent, but I'd settle for any info...even if that means I need major repairs

I told my friend to order the NGK platinum ones, but if you think this is unnecessary he can cancel the order.

...Please give me some info, I'll be eternally grateful.

 

[trueblue]

I would also clean the MAF, (mass airflow Sensor). Costs nothing except a can of brake cleaner.
Check for any vacuum leaks as well around the intake manifold. There is a blanking plug that can become brittle. There is a picture somewhere on here in another thread.
Make sure the airfilter top is fully secure. The bolts tend to rip the threads out so you cant tighten them fully
It could also be the Hego sensor breaking down but that will be expensive to replace from new.

Good luck

 

[Lud1konj]

Per your instructions I've checked the air filter box...I bought the car in November of 2012 and the air filter was changed back then so I didn't even bother checking it (my mistake, too naive). It seems that the box is not secured since the bolts that hold the top of the box to the bottom can't be screwed in (I guess somebody tried to forcefully screw them back and the bolt threads are gone...just as you diagnosed). I'll have my friend clean the MAF and repair the box...My last car had a crack in the upper part of the filter box but it didn't stutter and buck like this. Are Pumas really that sensitive to intake problems ? How come the stuttering wasn't that pronounced before the new plugs? If this is why it bucks and stutters, I'm gonna be the happiest man alive :grin:

Thank you trueblue for your help, I owe you a beer, cheers :wink:

 

[Lud1konj]

So I've checked the blanking plug and it's fine (still rubbery) and everything behind the MAF sensor seems to be airtight

I've made a video...this is how the car sounds while in idle (coldish start)

[youtube]http://www.youtube.com/watch?v=1ZKolzlhc6Q[/youtube]

Before the new spark plugs same rough running, but it wasn't as loud and pronounced as this.



I'm gonna clean the MAF sensor and repair the air filter box on Monday and hope for the best...I'll keep you posted.

 

[fairlight]

That sounds like its down one cylinder, get a decent well insulated pair of pliers, with car idling pull off number 1 (timing belt end) plug cap if it runs worse this is not the faulty cylinder. Repeat until no change in the way it runs, you have now identified which cylinder is playing up. After that you have to work out what's causing it. Coils, leads, plug. Injector, leads on correct post on coilpack?

 

[scofield.1]

Hi,

I had similar problems and solved them by changing the distributor cap!! or should I say Pumanoob solved the problem by changing the distributor cap!! Before that I changed plugs , leads, airflow sensors, cleaned MAF and Airfilter and a couple of things to, none of which solved the problem! Would suggest borrowing one from a friend and checking before buying, if it is the problem you will know from a very short trip in the car.

 

[martinthrapston]

there is no distributor cap,only coil pack

 

[Lud1konj]

Hi,

I had similar problems and solved them by changing the distributor cap!! or should I say Pumanoob solved the problem by changing the distributor cap!! Before that I changed plugs , leads, airflow sensors, cleaned MAF and Airfilter and a couple of things to, none of which solved the problem! Would suggest borrowing one from a friend and checking before buying, if it is the problem you will know from a very short trip in the car.

Other than you, four more of my Ford mates said it's probably the distributor cap or ignition pack (or whatever is the correct name of that part).

Closest thing one of them has is a Ford Escort ignition coil (he said it was a Zetec engine so it might fit...donno...). I'm gonna go to that mate and try to fit his ignition coil.

I'm gonna do this first, before anything else. Thanks :wink:

EDIT: It's from a Escort mk6 1.6

 

[scofield.1]

Yep its a coil pack not a distributor cap!! as its electronic ignition not mechanical, just like everyone to know I have not really got a clue lol good luck!!

 

[oilburner]

It won't fit the Escort is a Zetec engine and the Puma has a Zetec SE completely different engine

 

[martinthrapston]

check coil packs are same connections where the cables fit into the socket and also the ht leads connect to,there are 2 different types,but both work the same way,just use different ht leads

just checked and the socket is the same on puma and escort,depending on year its different ht leads that are used

 

[Lud1konj]

Fixed the airbox, cleaned the MAF sensor and checked if the ignition coil was faulty with a brand new one. My old one was putting out a good amount of voltage on all of the 4 lead connectors (not as much as the new one, but still reasonably close for a 16 year old component). The car still preformed badly, idle still rough so it most likely is not the ignition coil.

Now it's down to the new cables (they arrive on Monday).

 

[trueblue]

Have you checked the timing ? Could be that your belt has jumped a tooth throwing it out. Just a thought ???

 

[Lud1konj]

Problem solved...Seems that one of the new spark plugs was defective (guarantee not accepted...w/e). After another new one it stopped idling like a pig and with the new spark plug leads the car no longer stutters at low RPM...So...what have we learned today? Don't overlook the obvious >> factories make flawed products :x