Hesitation When Accelerating During Warm-up

[Southcoastdweller]

I have owned my 1998 2.3 since 2000 and she has been a reliable workhorse, but recently an unusual problem has developed when warming up.

 

The engine starts fine, idles evenly at usual higher revs, around 1200, then if left idling will warm up and slow to standard idle after warm up, still running evenly.

 

However, if driven straight away, from cold, initially acceleration seems fine, but after a short while hesitation sets in. This feels like fuel starvation, as if the choke on an old car had been pushed in too soon.

 

The hesitation only seems to be under load. If the clutch is dipped the engine revs freely and evenly. After a mile or so the problem suddenly stops and the engine runs sweetly as normal, with the usual brisk, even acceleration. Once warm the problem is not evident at all.

 

I recently had an electrical misfire, which was cured by a new coil, plugs and leads. (as an aside, for information, brilliant price for the coil at Kimber Car Parts, £31.66 inc VAT and delivery - http://www.kimbercar...uk/Default.aspx)

 

Regarding the current problem - The MAF seems clean and clear, checked the engine temperature sensor; resistance reads as per Haynes manual values, no obvious leaks in induction evident.

 

I have scanned the previous posts, but can see nothing similar, any ideas or suggestions would be most appreciated.

 

Thank you in anticipation