1998 Other Hyundai Models 98 Excel surging under load

CHOOKY

MEMBER
1998 HYUNDAI
4 CYL
FWD
MANUAL
145,000 MILES

My 98 excel is surging/tugging when accelerating and cruising. I replaced the timing belt only a few months ago and as recently as last week replaced the Crank Angle Sensor. These two new parts only seemed to aggrivate the problem. I have reset/recalibrated the computer but to no avail. I gave it a major service approx 6mths ago so shouldn't be anything as simple as plugs, leads, belts etc.
I have had 1 dealer and 2 other mechanics look at it with no answers. It isn't spitting out a fault code but it is a major problem when cruising as car loses momentum.
Any advise would be greatly appreciated.

2 Replies

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

I would be looking at contaminated fuel, blocked fuel filter pump pressure, and have the coil checked under load on an oscilloscope.

Start there.

Mark (mhpautos)

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Thursday, July 31st, 2008 AT 1:19 AM

SNB53

MEMBER
3 POSTS

I Would be replacing the leads. It is a common problem especially in the DOHC models bought out in 98.
They tend to get a hairline fracture in the Bakelite section of the lead that connects to the plug. This will normally not show up or cause problems under simple conditions, however when under load (heavy acceleration) it then tends to show it nasty side by intermittent missing and jerking acceleration. They also have a tendency to break when changing the plugs as the heat generated between the cams is so great it tends to weld the leads to the plugs so if changing plugs be prepared to replace the leads.