Thread: Stumbles, Hesitates upon heavy acceleration

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it idles good, but when i put it in gear, it shakes a little, then it becomes smooth, it shakes a little more, and so on. I can see the rpm go up and down by 100-200. Say you are doing 20km/h, and you punch it, it backfires and barely goes. Once it's in the higher RPM's it stops doing it. As the RPM drops below 2k, if you punch it again, it will hesitate and stumble some more, until its at the right RPM.

How do I test the egr and the vacuum pressure regulator on this thing? I put a vacuum pump on the egr, and it doesn't leak or anything, so I guess it just sticks. Just pure speculation. My idea is that if the pressure regulator doesn't know how much pressure to give it, it will keep the egr open. What do you guys think?

Originally Posted by vdorobantu

How do I test the egr and the vacuum pressure regulator on this thing? I put a vacuum pump on the egr, and it doesn't leak or anything, so I guess it just sticks. Just pure speculation. My idea is that if the pressure regulator doesn't know how much pressure to give it, it will keep the egr open. What do you guys think?

i think one of those Honda's has chocked your chicken.

ok if you're getting an EGR code theres 1 of 2 things that will make it throw that code, either the EGR is dirty or the EGR amplifier is malfunctioning.... the EGR amp is a common problem on fuel injected fords and very easy to replace.... shouldn't cost more than $40... if you had a scope meter or a vantage, you could check the amplifier and see if you are getting a proper signal pattern from it.... clean the EGR first with brake clean though.... then clear the code and see if it still happens, if so.... its gonna be that amplifier... the actual EGR hardly ever actually fails

By amplifier, you mean the egr vacuum pressure regulator? I have 1 vacuum line that goes from the throttle body, to the regulator, and the other one goes from the regulator to the egr(both hoses are not cracked, and the hole in the TB is clean). Here is a link, maybe you will have a better idea of the system - http://www.fordscorpio.co.uk/egrmonitor.htm . Isn't the egr spring supposed to keep the valve closed, and upon backpressure from the exhaust, it should open it, and that valve regulator applies pressure to keep it open? I would like to clean the valve, but there is no way i can spray it while its on the car(unless i do it from the vacuum hole on top), because if i have to take it off, the intake has to come off too. It's in between the firewall and the engine, righ by the heater core tubes. It can't be done without taking the intake off(unless i pay the dealer a fortune and I don't have to worry about it).

I also forgot to mention one thing, my cat has a rattle in it, and I'm positive its not a heatshield, because with it on a hoist, i banged on it, and i hear rattle rattle. I yanked on the shields, but, they were pretty stiff. If it would be partially plugged, wouldn't that be the key to my answer? Wouldn't a plugged cat make too much backpressure, and cause the EGR to be open at all times and throw me a P0402 code(EGR sys excessive flow)?

An aftermarket universal cat is like 50 bucks, so i'll just replace that before thinking about anything else. I'll do it monday and let you know how it went.