hello guys ,, I got some question on a 93 dak thats kinda driveing me nuts ,,Heres what i have ,,93 dak extenda cab 4x4,,3.9 mag auto 153,000 miles ,,I bought this truck for a song from a guy who couldn't get it running,,he told me one day he went to drive outa his driveway and it just died and wouldn't start,,he replaced the crank sensor ,the pickup in the distributor,,the ignition switch,,and he even tried another computer ,,well i had a idea it was the bad splice wires and he said he never looked at them so i bought it and hoped it was the problem ..
well i got it home and sure enough one main wire had corroded in half and after fixing them ,,it started right up,,,that was around the first of november ,,it was still warm temps ,,ran great till the weather turned colder ,,now ..when ya start it it starts right up but runs really crappy till the engine temp comes up to op temp ,,then it runs fine ????i replaced the wires ,,plugs,,dis cap,, fuel filter,,and gas cap and pcv valve ,,and still runs bad till it warms up ,,i checked the vacume lines a couple times and did eventually find a line off below the TPS on the intake and still runs bad cold,,i checked for computer codes and only code it pulls is a 55 code,,once it warms up it runs great.. but cold it misses and kinda surges in gear,,it idels fine but under a load just isn't right,,this is the third dak i've owned and the only reason i got this one was i have another dak exactly the same as this one that i figured would be a good doner for any parts i needed ,,the motor in the other dak runs perfect,,i can start it in sub 0 weather and go ,,not the case with the new dak..lol..any ideas ?also the new truck had the timeing chain replaced by the preivious owner before the issue with the wire splice ,,
thanks in advance
crazy

 

Check ignition components, plugs, wires, cap, rotor. Also do a vacuum test on the motor and a compression check wouldn't be a bad idea either.

 

already changed the wires ,plugs ,dis cap and rotor,,and same issue,,untill it warms up it runs like crap ,,once it's warmed up it runs fine ..no codes in the computer,,i would figure if a bad sensor was the issue it would have thrown a trouble code ,,no issues with starting it..it idels fine even cold.. just when ya give it gas cold it runs bad,,i checked the tps with a volt meter and it seemed to be smooth voltage thru the throttle range with no breaks or irratic voltage,,i didn't check the map sensor figureing that should have thrown a trouble code ,,but nothing..thats what puzzeles me.. no codes ,,oh i forgot the preivious owner did change the coil also trying to get it to start,,
crazy

 

First thought miles? if vac feed for map sensor is crudded it is smaller when cold as engine warms diameter increases. Had this happening on 89 capped sensor tap and added longer new tubing tapped at blank manifold spot truck now fine.

 

thanks ,, i think i know the spot your talking about ,,there is a capped line at a 3 way conection on the passenger side of the map sensor ,,there is also a small inline what looks like a filter,,after the 3 way junction,,i guess it's called an orifice,,will look at those items closely,,thanks again
will update if i can figure it out,,
crazy

 

Yep you got it thats where I tied in. Further, I actually bought a new sensor it didnt fix it. Re fed vac line there installed old sensor - all was good, C.Crest even took the sensor back, rofl

 

well checked out the vac line beside the map sensor..,, the line was very brittle.. and when i went to take it off it had a crack in it on the underside of the hose ,,replaced it and will do a test drive tommorow and see if it cured the cold blooded issue,,it did start right up and seemed to idel better than before ,,the tubeing looked clean ,,will be looking at ALL the vac lines now ..thanks for the tip
fingers crossed ..lol..
crazy

 

If I can be of any help to you with all the guys you have helped I am happy to do so.