• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

Bad stutter under throttle

Jbalch

CEG'er
Moderator
Joined
Oct 7, 2010
Messages
376
Location
Vancouver, WA
Hey everyone, it’s been a LOOONG time since I’ve been on here! I have a basically stock 98.5 SVT and it is not running well at all. If I’m light on the throttle like really light on it, it will accelerate ok but otherwise it’s BAD. I have had a couple of misfire codes. I replaced plugs, wires, ignition coil and fuel filter. I’ve actually done the plugs and wires twice just for kicks... it’s been like this for a couple of months. Any thoughts?

If I hammer the throttle and let it struggle I’ll get a CEL that says cylinder 6 misfire, plug looks good and wire seems good. Is it possible I got a bad ignition coil? It’s an accel brand one I believe. The car has 200k on her but was running great until this. Now it’s my sons car so I haven’t been super eager to get it running SUPER great... it keeps him going a little slower! ;-)
 
...... Inlet Manifold Runner Control working properly ? Stuck open ? ....G.
 
Also check the herd of electrical connectors on the rear valve cover, passenger side. Electrical connection problems here can cause misfire issues, as the coil trigger wires go through one of these connectors. These connectors also handle cam and crank sensor signals back to the PCM, and crank sensor signal problems can manifest as ignition issues.

Agree with Don, some of the aftermarket coil pack choices for these engines are... sub-optimal.
 
You cannot see shorting down the side of an otherwise normal looking plug or the internal resistance of a plug wire AT ALL. Meaning a visual check can be worthless there.

And I wouldn't give $5 for an Accel coil at all. HIGHLY overrated. These are not the days of Accel in the '60s and '70s................
 
Thanks for the tips! I have REPLACED the plugs (all of them) and wires twice so I’m thinking those should be good... checked the IMRC and it’s all good, opens and closes depending on rpm.

The stutter also causes a backfire if I keep the pedal down.

Connectors and wires all look good. Would seafoam through the UIM Help potentially clean the injectors? Or do I need to tear it down and take them out?
 
Seafoam thru the fuel tank is probably a good way to go, for injector cleaning. It may take a while to work its magic.

There is no substitute for removing the UIM to clean it.... you really are only cleaning the cylinders putting seafoam thru the TB.

.if the misfire is still localized to no.6 cylinder then .... could be a cam follower that is blocked / dirty inside, causing it to operate erratically.

Does the oil get changed regularly, are the cam covers clean inside ? is there lots of oil inside the rubber bellows on the TB where the front breather pipe connects ? ...G.
 
I do oil changes every 7k with Mobil 1 synthetic. The rubber bellows are pretty clean. I’ll try some seafoam in the tank for a few tanks and see how it goes. If that doesn’t help I’ll do more of a tear down and clean the injectors.
 
.... interested in the injector cleaning procedure.

This has come up a few times but I've never seen it done ... ie removing / replacing the filters.

Seen a flow bench for metering, matching and balancing sets.... stuff like this is always good to know ...G.
 
Back
Top