motor jumpy and stuttering after explorer intake install

j-wigg

New Member
Oct 5, 2008
32
0
0
using 98 upper and lower. all torqued to specs. used explorer 19# injectors. all new gaskets, stat. cleaned rotor connectors on dizzy. added fuel injector cleaner. smog pump was removed and egr disconnected. vacuum lines that are connected to the upper intake are pcv, vacuum tree, fpr, and vacuum check valve. all other's are capped. on the stock i had a line going to the map but current that line is capped from the upper with a tube coming out for a quick install to the map. the map is not capped (opened to atmosphere). the solenoids for the egr are all still connected but no vacuum lines are connected. there are a few small ones that went to the smog pump that are free (worked fine on the stock intake). stock tb and egr block. tps was not disconnected (was set fine on the stock intake). dizzy was not taken out. only the top part. so i didnt have to restab it.
edit:::: put old spark plugs and the bolt back in the rear of the heads to plug the holes that were for the smog pump.

at first the car wouldnt idle. adjusted the idling screw, fixed the spark plug locations on the dizzy (my 2's and 7's looked too much alike) and got it to stay on at about 700 rpm but was sounding pretty rough (actually the same when the 2 and 7 plug where switched). rechecked all spark plug locations. when throttle was opened to about 4000 rpm it was very jumpy. when it was going down from 4000 it sounded like the car wanted to just go dead and stall. lots of smoking coming from the exhaust. (the pro dumps left 2 nice black marks on the driveway, lol)
edit:::: on the edge of the lower intake along the heads, dead center on the heads, there is a hole that was in the heads that is partially showing. there was no passage ways for that hole that i could find but about 1/3 of it is showing
sounds like a vacuum problem. hoping not past the upper.
timing shouldnt have to be adjusted, correct?

btw... my first swap. i figured it wasnt going to start up perfectly but i sure had that vision of it working perfectly the first time. lol. what was i thinking.

here is an edited pic of how i have my vacuum going.
does it matter where they are connected to on the upper intake
88Stang50Vacuumedited.jpg
 
  • Sponsors (?)


Sounds like a vacuum leak or a spark plug wire in the wrong place. A vacuum gauge will help determine if you have a vacuum leak.
You should see 16"-19" vacuum at 700 RPM.

Vacuum lines to supply vacuum are not location specific. Vacuum is the same at all manifold locations.

The HO firing order is 1-3-7-2-6-5-4-8.
Non HO firing order is 1-5-4-2-6-3-7-8
attachment.php
 
getting about 12-14 at idle (about 700) rechecking all lines.

is this the vacuum check valve and does that stay on when the smog and egr is removed?
IMG_0011a.jpg


current upper intake connections.
IMG_0013a.jpg
 
ran codes. getting koeo codes 85, 67, 53. 67 i am not conerned about for the clutch safety switch. 85 Canister purge solenoid circuit failure and 53 TP circuit above maximum voltage.
when it warmed up and idled at about 1000 it was reading between 16 and 20 but was still extremely smokey
can anything electical give vacuum problems? that i have hooked up and unhooked?
 
blocked off vacuum line going to "S" on the vacuum tree to eliminate that and the rest of the hoses connected to the tree. same issue. tps reset to .998

any ideas?
 
just for $hits and giggles. reconnected the pipe that is for the smog pump to the back of the heads to make sure the plugs werent causing a problem. kept the end plugged. same problem. smells like the car is running rich. blueish tint smoke coming from the exhaust. i spoke with someone from a parts store. suggested to hook back up the map vac line when i was asking about a adj fpr. that is one thing that i havent tried. any suggestions. ran out of gas so i'm done for the night. and i ran through about 2 gallons really fast.
 
i didnt do engine running codes. connected bap or map (i've heard with 88 speed density it is bap but with 89 maf its called map) either way 18 psi steady at 750 rpms and running good. got a little high oil pressure with a little tap but thats cuz theres a lil too much oil. gonna get rid of some of that and hopefully move on to the next project.