Acceleration surge

[bourne]

94 xl-bought it 3 yrs ago and doubt any maintenance was done to it.186 000km as of right now.(put 25 000km on it in 3 yrs)
Engine light was always on until last month-no passing gear and more bog than I have during spring clean up.-Got fed up going into work so I shifted into 1st and matted it for a 1/4 mile....it finally broke away from 3000rpm(which it couldn't do in park) and slowly crept up to 4000rpm,I then shifted into 2nd and hammered again for a 1/4mile..it crept up to 4000 all the while making me feel like I was riding a bull at the rodeo... shifted into drive and had a passing gear. It has performed on and off since then with engine light only staying on after hard acceleration and only for 15 sec max.I know EGR is shot because it has just about rotted off but the truck is running so rough @ times that I doubt that it can be the root of the problem.If this was all that the truck did I wouldn't care but a few days ago,it started stalling and revving on its own in the driveway.I've never called it "Christine" but Stephen King is starting to piss me off. It needs to be given gas a few times on start up so it won't stall(always has during winter).When I drive it,and keep it working,there are times when I feel it hesitating while constently feeding it gas but the biggest noticeable thing is when I'm feathering the gas, it sometimes surges and then automatically stalls(at speeds under 70km and a few times above).The scary thing is that a few times now, while waiting for a green light, the engine has revved and the truck has wanted to jump forward.Wifey is not touching Christine until she's fixed.As far as jumping ahead,when it's doing it, it'll act the same way when slowing down and the tranny has just downshifted.-Changed the plugs and wires last nite-noticed more performance on first test drive(engine light would only flicker after suddenly letting off of gas after hard acceleration) but back to the same thing since.Changed fuel filter 5000km ago and had fuel system flushed????1 hour plus- no big difference.Last thing that Homer the mechanic did before I should up, was to Plasma cut my 2 catalics open,and air hammer out some of the honey combs to see if they were clogged...which they weren't.(You should see the smile on my face right now...)One last thing, when it's gutless, hammering down feels like the tranny is slipping until I ease off just a bit.It will then accelerate well but without the passing gear.

Please help my truck or I will shoot it Just kidding...I'll trade it in for snowshoes-winter's coming

 

[NHale623]

Yes, a malfunctioning EGR system will cause your engine to surge.

Pull the codes.

 

[bourne]

Thanks for the reply NHale623
I'll change the EGR because it has come up on the code in the past.Would it more than likely solve the stalling problem when driving and the bogging?
When you pull codes, will it pick up everything or stop @ the EGR and not find any other problems until EGR has been repaired?
Thanks in advance

 

[97greenmonster]

It should give you all codes that need to be read, other wise the dealer would have a hay day with you!

 

[bourne]

Thanks-I think 75$ for 5 minutes of Bill Gates stuff is a hayday on its own.I should of bought grandpa's '67 pick up.-8 plugs and 1 belt to change, hell, I could have sat inside the engine compartment and drank beer while changing plugs.

 

[NHale623]

Don't what the problem is. I do know a bad EGR system, encompasses more than just the EGR valve, will cause surging at idle and while driving.

Don't waste your money by buying parts and hoping something works. The time you spend learning what makes your truck work and learning how to diagnose systems is time well spent.

 

[97greenmonster]

Thanks alot for that responseMHale623.. i agree completly with that. once i bought my 97, i bought a chiltons, studied it, read so many forums here, and searched other places to see exactly how my truck ticks, and it helps out alot, whan something goes wrong, (with nothing has, knock on wood) i will know how to aproach it, being a DIY repair or if i hav to have a shop do it!

 

[RACEHEAD]

Racehead

I have a 91 explorer in mint condition... a few weeks ago I noticed a surge when accelerating. I changed the plugs, wires, cleaned the MAF, IAC, Throttle Body and fuel filter. Although it seems better... I still notice a surge when at high speeds more than moderate speeds. In addition, when starting it up cold in the morning it never starts on the first try, and always on the 2nd attempt. The truck seems to have very good acceleration and compression, and idles normally, this surge is consistant with constant acceleration and highway speeds. Yesterday I went out to test it and decided to run it by the cruise control... the surge was more erratic than when operating with the cruise off. Is this a vacuum or fuel issue, or a possible faulty TPS, VSS, FPR, or fuel pump? I will conduct a test with the code sensor over the next days and perform the seafoam cleansing. If anyone has the short cut to this mystery. I would appreciate your input. Thanks in advance for all of your time and info.

 

[ma96782]

Check fuel pressure.

Aloha,Mark

 

[RACEHEAD]

Thanks Mark, what's the best way to do the fuel pressure test.

 

[RACEHEAD]

Mark, I believe that this link answered my question.
http://www.explorerforum.com/Singleton/web/pages/fuelpr.html