PDA

View Full Version : No Acceleration @ HWY Speeds, Stutter...?



ccec
01-12-2013, 12:50 PM
Hi All,

This behavior started last week: no acceleration when trying to pull on to fwy on-ramp, no kick-down when floored. Slight stutter @ 65 mph.

Idle is very good. Slow starts up to speed are fine.

I'm thinking my weekend project will start with new fuel filter... I don't when, if ever, it's been changed (1993 LWB, 4.2 w/ 162K on rig).

Anything else?

Thanks,

--ccec

singingcamel
01-13-2013, 01:17 PM
I'd check for vacuum leaks, when was the last time you tuned it ?

ccec
01-13-2013, 08:10 PM
Tuning is solid... Rock-steady idle, good acceleration 2 weeks ago. I only put 1500 miles/year on her... Pampered. Died today going around the block. Will re-start for 2 seconds then quit. I'm gonna go through the fuel system (filter & fuel pump), trusting my ignition for now...

Cheers,

--ccec

singingcamel
01-14-2013, 09:58 AM
I've seen bad coils act like this , check your coil, try another one and check connections at the coil.

o2batsea
01-14-2013, 02:55 PM
In order of probability:
Ignition amplifier module
failed wiring
Vacuum leak
Alternator or coil (equally weighted)
Fuel pump

Any error codes on the on-board readout?

ccec
01-15-2013, 12:23 AM
In order of probability:
Ignition amplifier module
failed wiring
Vacuum leak
Alternator or coil (equally weighted)
Fuel pump

Any error codes on the on-board readout?

Thanks o2batsea....!

No error codes...

My gut is telling me items 1 -- 4 are solid: I.A.Module never had probs, wiring solid, new-ish vacuum lines, alt. & coil good...(?) I ordered a new fuel pump from Rovers North today.... Logic: at 162K, and as the 3rd owner, I don't know if it's ever been replaced, I might as well do itm (as well as the fuel filter)... But will systematically replace and test each item one-by-one, so that others may learn...

--ccec

ccec
01-19-2013, 09:15 PM
Problem solved:

Changed fuel filter. Engine still died.

Replaced fuel pump. Runs perfect.

So the take-home message is that a huge flat-spot on acceleration eventually morphed into a string of stalls and non-starts. Thankfully, it wasn't something electrical.

Cheers,

--ccec