TCCoA Forums banner

1 - 20 of 57 Posts

·
Registered
Joined
·
84 Posts
Discussion Starter #1
Hello fellas... ok, I have been on here and have looked up everything I can on this car. I swapped out motors from a doner 35 ann edition with 114k on it. the original motor spun a bearing or something, got the car free.... Okay, so... motor swapped, fresh oil, new fuel filter, new autolite 764's, new cables, and it still wants to run like a$$.... unplug the MAF, and it smoothens out for a bit, then runs rough, then dies. plug it in, it dies.... changed the MAF, still same. checked, and rechecked for the 5th time, no vac leaks. I used to own a 90 SC and I know what they are capable of... I just need to get this thing running right, then I can do all of the body and interior...

my main concern is that If it isn't running right, I have no need to focus on other stuff.... this is a 90 T-bird, SC, sealed up the IC tubes with copper permatex, and was going to but the teflon gasket set next week... maybe it will help, but any and all opinions are welcome. thanks in advance, Matt
 

·
Registered
Joined
·
84 Posts
Discussion Starter #2
also, I forgot to mention.... when she starts, I have engine shake, pretty good too... but @ about 2800 rpm, it smoothens out, my vac is running about 17-18in and boost gets to about 7-8 max... when WOT, I have a black watery substance coming from the tail pipes... cats???? it's not fuel, but smells kinda rich... tail smoke color is more of a whitish grey.... ??? thanks again...
 

·
Registered
Joined
·
1,731 Posts
is it possible this donor motor had bad head gaskets? check your oil see if you have any coolant in there, that would be the first step to look at with these engines. If you check that and it looks ok it could still be an issue(especially with the water and smoke you were explaining). See if you notice missing coolant. Start there and get back to us.
 

·
Registered
Joined
·
84 Posts
Discussion Starter #4
ok, will do... Man, I would hate to have to pull the entire top end apart, would probably just yank the motor, and rebuild it if I had to take it out again..... I'll let you know. thanks
 

·
Resident Line Creator
Joined
·
1,874 Posts
And if your not sure by checking the fluids you can do a compression test as well.
 

·
Registered
Joined
·
84 Posts
Discussion Starter #6
got it! no water or coolant in oil, but it does smell a little gasy..... running rich? I am thinking change out the ecm... what are your thoughts? maybe with not very sealed ic tubes, it's telling the computer, "more fuel, more fuel" to make up for the extra air coming in? just a thought... maybe i'm totally in left field... plug in maf and it dies right off the bat... i'm soo lost. thanks for your input...
 

·
Registered
Joined
·
1,731 Posts
when you swapped out the maf was it for a new one or a used one? when my cars maf was shot as soon as I would plug it in it would die. Also pull your plugs, see if they are clean or damaged at all. did you see or hear this motor run before installing it?
 

·
Registered
Joined
·
84 Posts
Discussion Starter #9
new plugs, used maf and I didn't see or hear it run, it was hit on pas side while driving.. wiped out rear rh quarter, and part of the pass side door.... i'll double check the plugs, and who knows, maybe I cracked one putting it in. never have before, but hey anything is worth a shot. thanks. I will pick up a new maf as well.. what about swapping computers... ne chance the programing might be different due to elevation? doner car was from az. and I'm in ut.
 

·
Registered
Joined
·
1,731 Posts
I highly doubt elevation is the issue, however your ecm could have some type of issue, what ever parts you get check if they are returnable so if they don't cure the problem you aren't just throwing your money away.
 

·
Registered
Joined
·
84 Posts
Discussion Starter #11
what ever parts you get check if they are returnable so if they don't cure the problem you aren't just throwing your money away.
:zbeer: good call... didn't even think about that... would have bought whatever and prob ended up with tons of parts i didn't need lol... more work on her tomorrow..

have any of you used car innertubes cut out to make up IC tubes at connections instead of buying teflon gaskets or that permetex crap? might try it myself...
 

·
Registered
Joined
·
84 Posts
Discussion Starter #12
ok fellas... I didn't get time to do anything on the car today, had to tear into a taurus... so tomorrow, I am going to swap out ecm, and if that don't change anything, I am going to try sealing up the IC tubes again, and if that don't work, I am going to do a compression test. what should be a good compression and about where should it be on the 3.8 sc'd engine's 1st stroke? and my other question, don't it usually bleed of a little or does it sit solid till I release the pressure in my gauge....... I haven't done many, but that's cause most time I haven't needed to do it....... thanks....
 

·
Registered
Joined
·
718 Posts
if it runs like **** at idle I'd doubht it would be the tubes not sealing,,

A: do a compression check

B: ohm out those plug wires and make sure none are bad (ive had plenty of new wires that are bad outa the box)

C: what about a bad coil pack?

D: check the plugs for cracks in the procelian,, sometimes stockers drop em and then they are junk.

If it smooths out around 2800 then its sounds like its missing a cylinder possibly 2,, if no vacuum leaks then I would definately pull the plugs and look at em,,, maybe one is darker or wet or oil soaked and that would be the one to have the problems.

"" when doing the compression test you want someone to hold the throttle wide open (coil pack unplugged! and all 6 plugs removed) then crank it over letting the engine rotate about 3-4 times till you get the highest reading on the gauge.. record it and move onto the next cylinder.. obviously the max pressure is important but more important is that all the cylinders are within 5% of each other. if you come across a lower cylinder,, remove the gauge and retest it.. I'v had those gauges not seal sometimes causing a false reading.
 

·
Registered
Joined
·
84 Posts
Discussion Starter #14
compression test results.

First stroke Max psi
#1 100 135
#2 105 136
#3 100 132
#4 100 135
#5 105 138
#6 103 132

checked plugs.... all good, but they were all an even black color, not a brownish. but they are new too.... what ohms should the cables be at?

today I will change out the coil pack, and buy some new hose for all of my vacuum lines.. I really don't think there is a leak, but might as well, that way I know I can rule them out.

I will post up my results after cp and new vac lines. thanks for all the input...
 

·
Registered
Joined
·
718 Posts
compression test looks good.

alot of plug wires differ but 150 ohms per foot i believe is about the norm.

make sure the coolant sensor is good or perhaps install a new one,, it has alot of basis on what the rich/lean levels are at.. after warm up it starts to read the mass-air and 02 sensors
 

·
Registered
Joined
·
84 Posts
Discussion Starter #16
Alrighty, here we go.... changed out coil pack... same... changed maf... same... plug it in and cover up most of the maf intake, and it idles really well. move my hand and it dies, sucking in too much air... would a bad IAC valve make it do this? I resealed the IC tubes... eh, same.... I just don't understand why when the maf is unplugged, it runs smooth for 2 min or so, then dies... I plug it in, smooth, then rough shaking and kaput... dies... I wanted to run a cold air intake, so I bought everything... and that's how I figured out if I hold my hand to the maf intake, plug it in, it runs real smooth... ???? I'm sooooo lost... I am :bangwall: here trying to figure it out... new pcv valve today too..... ne other sug???? sorry this is so long... I'm kinda venting.... but I really thank you all for your input! oh... I have a bad valve cover gasket leak on the LH side... right up front... would this have anything to do with my problems I'm experiencing?
 

·
Registered
Joined
·
84 Posts
Discussion Starter #17
bump please..... needing input badly.... don't want to give up.... what about changing out ecm, and/or complete throttle body???
 

·
Registered
Joined
·
84 Posts
Discussion Starter #19
ok, so I changed out the temp sensors.. both... and I am going to change out the valve cover gasket. then I should have my teflon gaskets for the ic tubes.. I changed out the dis module. If this don't work, I will change out the ecm, havent done that yet... that is last resort lol.. even tho I have one. then it's on to brand new vacuum lines, and I mean ALL!!! :) I will post in a few days, and let everyone know the progress... thanks for all the help.....
 

·
Super Moderator
Joined
·
7,617 Posts
If you put your hand completely covering the intake tube, and it still runs, then you definitely have a vacuum leak somewhere. Take a pair of plyers and crimp off one vacuum line at a time. When you get to the one that makes it run better when it is crimped, follow that line and see where it goes and where the leak is.
 
1 - 20 of 57 Posts
Top