Hesitation, 1995 sc 5 speed, during throttle transistion

92bird

Registered User
Hey guys,

A friend of mine just bought a 1995 5 speed SC with 101k miles. There is about 40k on the engine, as it was replaced by Ford a couple years ago.

It is completely stock except for a K&N cone filter.

The problem is, when slowly pressing the accelerator pedal to the floor, it hits about 3/4 throttle and feels like it just lost 30hp.. It is not missfiring, and is more noticalbe at low engine rpms.

We have done the following already which did not fix the problem:

New throttle position sensor
Cleaned MAF wire element (possibility of oil on it from K&N filter)

Any suggestions?

It runs well, but isn't as powerful as it should be. We played around with another local SC'er in his stock '93 5 speed, and he walked away from us.

Either that or I'm just used to my 400hp SC.. :cool:

Thanks,

Jeramie
 
A number of things

How is the vacuum at idle? It should be around 20Hg.
There may be a boost leak too.
Does he get any black smoke out the tailpipes when he accelerates?
Or is there any spark knock?
I would also try to pull any codes that the EEC may have.
Sometimes it's just a process of elimination finding things.
 
Check the balancer and make sure it is not broken. If it slips or is broke the timing will be retarded. This happened to me on my 89. I had no codes and just poor performance at the top end. You can't check timing with a timing light because the cranks position sensor just goes by the dampner not the actual crank. You will have to look at how true the balancer is running or remove the crank bolt and try and do a visual check on the balncer hub. Mine was wobbling and I removed it and it came out in two pieces.


Jerry
 
At idle the vacuum is about 18 HG, which is normal for the high elevation we are at.

No black smoke, no spark knock, and no codes either..

Balancer is solid.

If I re-set the computer it runs fine for a few minutes then does it again.. So its something computer/sensor related..

Maybe o2 sensors?
 
Jeramie
just do the fuel filter, it likely needs it anyway, then I'd be looking at vaccum & boost leaks. I'll bet you find it. Micheles which occasionaly hesitates & it has Idle surge. I think hers it related to the IRCM somehow since the fan isn't working correctly, & remember they put a fan switch on that car for one reason or another....IRCM related problem???

Whos the 93 SC, He, He

I really think that car is going to be fine, its just got a typical SC qwerk.
I'd do a HG test just to be safe too.
 
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