another stalling when slowing down thread..

[lucky03602]

searched, i checked my cts, and vac lines and nothing.

first off i swapped a 93 de into a 90 chassis. motor is completly stock with 218k on it.

i removed ALL emmissions (went thru all threads to do so) capped off all vac lines etc.. didnt do a comp check yet. replaced cap, rotor, and plugs.

the problem: when i first start the car it runs at about 13-15k rpm until it warms up then its 700-800rpm. it does hesitate a little. if i drive after a 5 min warm up then it stops from any gear with no issue, but after it warms up good then i go to stop it stalls down to like 100rpm and has stalled completly out.

this happens regardless if i do a slow stop or not EXCEPT for when i downshift into 1st and let it "drive" to a stop.

i havent replace wires or o2 sensor yet. also this engine sat in the donor car for like 3 years before i got it and started it.

i havent done the maf cleaning because its my daily atm and i dont want to possibly kill the maf off, and i havent adjusted the idle screw because its idles just fine and why adjust it?

its dead of winter here in southern nh so i dont want to constantly get under the car over and over so im checking multiple things at once.

[OutToWinPAHC]

It could be so many things, but 218K miles on the motor. Sensors and other things are also as old and used. I would check compression to see how healthy it is, then if there are no codes I would tune it up. Plugs cap, rotor, wires, time it. Clean the intake / TB / IAC. Clean all sensor connections, and recheck everything. Maybe try "Maf clean" and a seafoam job.

[martins_240sx]

you said you removed all emissions...did you happen to remove the iac?

[mrgreeneyes]

Im with Martins. IACV?

[lucky03602]

i agree with comp check, will do soon.

i did clean tb, iacv (no i didnt remove it, if you follow my name i actually had issues with my idle after i replaced it with a brand new one) and most sensors as i came across them.

i do have to replace wires like i stated, but i have a feeling its just an old motor haha.

well today it didnt feel like starting in the a.m. (-15 below with wind) so i pop started it drove to work, 11 hrs later got in it again wont start, drove home shut it off, went to start it 10 mins later and battery was dead, so now i got a alternator to check first and more then likly replace!

if not one thing its another haha

[martins_240sx]

hmmm I dont think you can sum it up to old motor. correct me if im wrong but this all seems like it started after you stuck your hand in the bay. if this is true you should back track your work. could be a vacuum leak. I suggest getting some seafom and using it as prescribed. when you crank it back on have someone hitting the gas while you look in the engine bay to see if the smoke is coming out of the intake manifold, vacuum plugs or where ever. If you do find smoke coming out then you prolly found your problem. smoke should only exit the exhaust, valve cover breather, and possibly out near the intake filter. anywhere else needs to be repaired...hope this helps and i meant no offense if any was taken.

[lucky03602]

no offense taken, i feel the same way.

i did look for smoke and i found none, and ill pick up seafoam tomorrow and do that over the weekend depending on weather and see if that helps.

[martins_240sx]

no no no I think you misunderstood me...when you put the seafom in. when you go to start it again look for the seafom smoke...you know how it smokes alot...excellent way to find vacuum leaks. make sure you do it at both idle and revved when your looking for leaks. In this senario we arent trying to clean the engine with it, we are using its smoking habits to troubleshoot.

[lucky03602]

yeah i did misunderstand you...nice help you are!! haha j/k

ill keep that in mind, i had to replace my battery today in a snowstorm, so ill probibly wait til a weekend with nice weather to do that and then i can let you know if i find any smoke. there shouldnt be a vac leak seeing how i have like 2 lines now but you never know.

all i have for vac is crankcase to fpr, and i have one capped underneathe the tb (kept it live for when i boost her)

[martins_240sx]

keep in mind a vacuum leak doesnt neccesarily mean from a vacuum line

[gnvarnadore]

another thing you might wanna check is the wires running to the alti and your grounds. after i swapped my motor i noticed my car was doing the same thing and it was due to the combo of a bad battery and the wire running to the alti wasnt getting a good connection as well as my neg cable on my battery not getting a good connection. all i had to do to fix the problem was throw in another battery i had laying around and tighten the wire that runs off the alti and then buy a new wire for the battery and it fixed the problem. best bet is to always check little things like that because they can be easily over looked when swapping in a motor.

[ag240]

it runs at about 13-15k rpm

but seriously, as mentioned above, check grounds. I went to the junkyard and found 0 gauge wire to use as my grounds. kinda like the hks grounding kit, but cheaper. just a thought.

[lucky03602]

i did check the gounds, and i cleaned up the ones on the alternator, and neg battery cable. i added one for kicks from the radiator support to the valve cover and didnt seem to help.