quick help needed on 94 sub

[catmandoo]

i'm looking at a 94 c2500 with 145,000 miles,pretty nice shape ,couple of options i wish it had but thats another story,anyway took it for a test drive today and cruisin down the interstate at 70 the ses light comes on ,i see it and back off the throttle and it goes out,also it has a very touchy pedal,it seems to somewhat surge if you just get on it a little ,does this sound like a pump taking a dump or something else,by the looks of it it doesn't look like the pump has been changed in recent history,and the fsd says in big letters stanadyne,i have never really checked one of these over that good,but it seems pretty decent other then those two things,engine is dry as a bone.they want 5000 for it so i figure if the pump is toast i'm still in pretty good shape.

[rjschoolcraft]

My 95 behaved similarly (except for the SES light) when I first got it. The throttle was touchy and when decending grades on cruise it would surge. Warranty pump replacement fixed the problem.

[markrinker]

I'd take another test drive tomorrow, and take a paper clip along to pull codes. Pretty simple on a '94, its covered here on the website.

[catmandoo]

what kinda codes am i looking for?for say a pump takin a dive,or fsd or?

[Uncle Wally]

If you pull the codes, just let us know what all came up. There are several of us with manuals for the 94/95 OBD I emmisions. We can tell what system there are problems in, if you have codes. Something to remember though, sometimes there are no codes saved to the ECM when problems crop up. Just a little forewarning.

Waldo

[whatnot]

I would check the vacuum system over good. It sounds like the vacuum pump might be bad or broken hose. With it idling, you shouldn't be able to move the wastegate linkage.
It is fairly cheap to fix.

[catmandoo]

ok i'll check the vac system over,i think i'm gonna buy it anyway,i figure he wanted 5800 and i got him down to 5000 so if the pump is going i'm still pretty close to the original price,and around here these diesel subs,are like hens teeth ,but just in case what trouble codes are shall we say (trouble)

[whatnot]

17, 18, 35 and 36 are bad ones to find. If you get 3 of them then it probably will need a new injector pump.
If the SES light isn't on then it probably won't have any of them though.
78 is the wastgate and usually a cheap fix.

[catmandoo]

ok thanks i'll let ya know tomorrow.

[rustypig]

Sounds exactly like the symptoms you see from a failed vacuume selenoid....if so...30 bucks. Check for broken/rubbed through vac lines to and from the vac pump and turbo as well though.

[ToddMeister]

If it has the light duty emissions package, could also be the EGR valve/controls setting the SES light.

[catmandoo]

thanks a bunch,heading over this morning,should know more this afternoon.