Very severe jerking accelerating mid-range

[SVXIoM]

I have a bucking bronco problem on my '96 UK model with 120,000 miles. From starting I have a slightly lumpy tickover and slight hesitations when accelerating but when the engine has been running for 1-1½ hrs acceleration in D between 1500 and 2500 rpm starting from the cruise produces violent jolting/mis-firing only stopped by dropping into 3 whence no problem. 3000rpm upwards in D produces no problem and is smoothest part of the range. No hi-revs mis-firing in any gear. Just replaced TPS and cleaned MAS but problem not gone away albeit smoother gear changes. No access to scanner here so may have to go to UK to find suitable scanner (what type suitable?). Any suggestions in priority order would be most welcome.

[Blacky]

Sounds like an ignition coil problem. I had a similar issue. The misfire is worse under load and when the engine is hot.
Try disconnecting one fuel injector at a time until no difference is felt. This should tell you which coil is bad.

Any regular OBD 2 scanner will give you a misfire code if the check engine light is on.

[SVXIoM]

Originally Posted by Blacky

Sounds like an ignition coil problem. I had a similar issue. The misfire is worse under load and when the engine is hot.
Try disconnecting one fuel injector at a time until no difference is felt. This should tell you which coil is bad.

Any regular OBD 2 scanner will give you a misfire code if the check engine light is on.

But would a failing coil cause this severity of jerking? The whole car jerks as though all 6 pots are stopping and starting simultaneously. My UK model is OBD 1, not OBD 2 and the only historic code showing on manual analysis was TPS so replaced TPS. Another thought is fuel starvation when the engine is hot and the throttle is depressed from cruise to accelerete.

[scoobymal]

My spare car (1992 jdm) developed 1 bad coil- made it virtually undriveable.

[NikFu S.]

Same here. 1 bad coil and my car was barely able to move under it's own power.

[SVXIoM]

Many thanks Blacky, Mal and NikFu S. Bearing in mind the problem only occurs when accelerating from mid-range cruise in 'D' is there a relatively easy/straightforward way of determining which coil is faulty? There is sometimes a slight 'hunting' at idle but not always.

[Blacky]

Read my first post.