Seeking some help and advice. Might be useful to give a bit of repair history first:
After major cylinder head damage, my Mk1 1.6 had a recon engine fitted 7 months ago which was imported from Japan with (allegedly) around 35k miles on the clock. Car has 156k miles. Also new clutch and belts fitted at the same time. Had some coolant leakage and new water pump fitted. Also PAS system leaking and various pipes replaced.
A couple of weeks ago the timing belt failed and had completely snapped. No evidence of coolant leaking onto belt. No obvious reason for the failure. Had belt and pulleys, tensioners etc all replaced. Bit of a gamble as RAC and garage told me that the engine would have been damaged, but on advice that this was a “safe” engine (thanks Robbie) I had the belt kit fitted and engine great and all was running fine for a week.
Then the misfiring started. Seemed to be running on only one cylinder. So bad it was practically undriveable so had the sparkplugs replaced, and a full service to rule out any maintenance causes.
Now it is better but not completely cured. Misfiring on acceleration, especially in higher gears, but runs fine once constant speed maintained (unless it is just less noticeable then). Real juddering and lack of oomph when changing up or down and then accelerating.
I would be grateful for any ideas and suggestions to cure the problem. I am ordering some new ignition leads - would this help? Is there anything else it could be, such as needing a new coil pack? Would I be able to fit these myself (definite non-mechanic)?
I have luckily found an independent garage who are happy to fit parts I supply (from MX5parts) and only charge me labour (not the same garage as fitted the engine - I lost all confidence in them). They are not however Mazda experts, so I need to give them as much advice as I can obtain from you guys, and if I can do anything myself that is a bonus.
Coil packs arn`t cheap but are easy to replace (although fiddly due to lack of room at the back of the engine)
Would be worth checking for fault codes too. I had a code 9 when mine wasnt running right (Water thermistor) which is under the coil pack so thats how i know its easy to replace the coils.
If you have work done on your car by a none Mazda garage leave the copy of the Rod Graingers Manual on the passenger’s seat so it is there if he needs it. So as not to upset the mechanic say you left it there because it has all the spec’s in to do with the car.
Thanks Pollyana, Great idea. I am bidding on one now. My garage would probably be grateful for the info, and I certainly could learn lots from it. I have one on CD that I bought from ebay some time ago, but it is difficult to read, very technical and I have to print out pages to take out to the car! A book is much better I think.
Thanks for all the help. I think I have solved the problem! The leads between the coil pack and plugs were in the wrong position! Must have been the garage putting them back wrong when they fitted the new timing belt and/or the new spark plugs. Link here to the useful diagrams which I found:
The garage are going to be very sheepish when I tell them! The manual will certainly be handed over for the next visit to the garage once it arrives from ebay!
She ran like a dream today and I remembered why I have kept her going. All is forgiven, 5. Smiley me all day.