98 Aurora surgin under acceleration

[fordpsdman]

Greetings all...firstly I'm a former Ford Power Stroke guy, so I may be slightly out of my league with gas engines

I just bought a 98 Aurora...love it so far. About a month after I got it, I got a 'low coolant" alarm. Finally found out the mechanical seal failed on the water pump impeller, so I bought a replacement and drove it to my dad's place to use his garage to replace it. As I have driving home ( about 4 hours away) I noticed that the vehicle would 'hunt' when I would accelerate to pass someone. As soon as I let off the gas and let the cruise take over, it was fine. When pulling out at stop lights, the engine would accelerate OK, but watching the tach, it was again 'hunting', swinging up and down under a hard acceleration. No trouble lights. So, I got it home, and changed my water pump. While in the process of washing the spilled coolant etc, etc off the engine following the replacement, I got my 'check engine' light. AutoZone scanned and came back with the MAF. Jiggling the wires and drying out the MAF connection took the check engine light off, but I still have the hunting / surging acceleration, regardless of engine temp, and regardless of whether I'm pulling from a dead stop, or up and rolling at 70+. Before I drop 100+ on a MAF sensor, I want to know if anyone else has ever experienced this, and if I'm on the right track.

P.S. I have purchased the tech manuals online for the 98 Aurora. It's my understanding that the same engine/drivetrain setup for these cars ran from 95 up to 2002 or 2003 (whenever they came out with the new body style) Anyway, I have full access to all the trouble codes, fault descriptions, entire technical specs, parts replacements, locations, etc, etc. Just like GM. So if anyone needs any info, I'd be more than glad to help. Please email any inquiries to '[email protected]'

THANKS !!!

[tjm]

First off - how are your plugs and wires - I know they should go 100k miles but don't believe it.

Next - fuel filter

Cheap things first - vacuum leaks - check the PCV valve elbows and the intake bolts to be sure they are snugged down.

Replace PCV valve and check air filter just to make sure the basics are taken care of.

Assuming that the code was set due to the coolant spillage; performance problems with no code are usually fuel or vacuum related. But, that's only if plugs and wires are good.

Do these things before springing for a MAF sensor.

[fordpsdman]

TJM:

Thanks for the input.

It's more than likely going to be one of the issues you pointed out, but being a mechanical engineer who does high-end mechanical inspections for industry, I've always learned to expect the worst-case scenario and prep for it, lol.

To eleborate on the fuel filter, I noticed today the the incoming fuel line (pre-injectors) was 'pulsing' during an idle. Leads me to think either fuel filter, or even possibly a malfunctioning relay which may be pulsing the fuel pump. At any rate, I'm going to try to find somewhere where I can jack the damn thing to get under it to change the fuel filter...I can't see paying Pep Boys 60 bucks to replace a 7 dollar part I can do in 10 minutes.

Thanks for the feedback man !

[oldsdad]

Something else you may want to look into is the FPR (fuel pressure regulater) if your fuel filter is original and dirty then you can bet some contaminates have gone throught to the FPR which will cause surge.These engines are great when everything is right but small things will cause problems.