2001 Expy XLT engine sputter/fail

[chadd1]

Hi Expy Owners. I have an issue that is stumping the service technicians and I needs some help.

I own a 2001 Expy XLT. Only modification is a Gibson cat back exhaust. No check engine lights or code history could help diagnose the issue.

Situation: Typically occurs in above 80 degree outside temps with AC on. I drive on the highway about 25-30 minutes (60-75 MPH), exit and sit in stop and go traffic for 10 minutes, then as I drive (35-50 MPH) the engine suddenly loses power and continues to sputter like it's out of gas. The RPMs stay around 800 or less and if I try to give it gas it boggs it down. Sometimes it stalls other times it just boggs and doesn't go. No check engine lights come on. I sometimes hear a clank that sounds like it is coming from under my feet.

If I turn the engine off and let it sit for 5-10 minutes, I can usually go again. I thought this might be an issue with my catalytic converter, but the tech said it the car would go just not above 30-40 MPH if the cats were clogged. The tech/service didn't want to start suggesting stuff that may not work. Anyone else experience this?

Chad

 

[Ward]

Have you ever replaced your coil packs? I had a similar issue with mine, no check engine light, and stuttering/hesitating at medium load. I fixed it by replacing all 8 coil packs and spark plugs.

 

[chadd1]

coils and plugs..

No, haven't replaced them yet. Something I'm considering. I would replace the sparks plugs at the same time. I see a set of 8 coil packs for $100. Is it worth it to pay $180 for performance brand?

So your issue cleared all up after you did this?

 

[Ward]

I wouldn't bother with the performance ones, I doubt they're worth it. I bought a set off ebay for about $100, and yes it cleared up my issue completely. I have read that these engines are picky about spark plugs, most people seem to recommend either motorcraft or autolite. I went with autolite platinums on mine. You will definitely need some ratchet extensions and a u-joint to get to all the plugs, it's a bit tricky.

 

[chadd1]

Thanks for the recommendation. I will change them out.