Car did run after mods, now doesnt

DarkProphet

DarkProphet

Founding Member
Aug 19, 2002
391
0
0
Quakertown, PA
#1
After doing the upper/lower injectors, maf, TB and headers the car started right up, and ran rough, but ran. I started it many times while doing the timing and it started effortlessly. Then, I was driving to my friends garage to change the oil and use his air tools to tighten up the exhaust when it started bucking real bad and running REALLY rough. I went to the side of the road and it just turned off and wouldnt start. Eventually i got it started by holding it at WOT and it would run VERY VERY rough and barely driveable. Back at his shop we put it up on a lift and noticed oil dripping from the back of the block. After putting the car back down i noticed it was the pcv valve, as it had popped out for some reason. The car STILL wont run however. We were playing with the timing, he had an extra MSD cap and rotor so we put that on, and still no luck. Once we get it started by holing it at WOT it seems to run half decently, though still rough. Anyone have any suggestions as to what might be wrong? i checked all the vacuum lines i can see and im getting 20 in of vaccume at around 1200rpms. The car just wont stay running though. Any help would be greatly appreciated!
 
#3
Use your timing light and confirm that you are getting spark at all 8 wires, and recheck your timing and set it to 10* BTDC if it's not there already.

You might have your dizzy 180* off. The car will run in this mode, just extremely poorly. Yank the dizzy and turn it 180 and retime it to 10* and see if it gets worse or better.

Next I would start with the basics. Check your oil and make sure you aren't getting coolant into your oil. Then check your fuel pressure, and your vacuum. A serious vacuum leak could do that too.

After that, check your plugs and see if any are running anything besides stoichometric.

You should also try to get the car to run for a while, maybe the computer will read off the O2's and correct for any rich/lean conditions. If so, you have a MAF problem.
Scott
 
#4
The plugs are brand new, so they shouldnt be a problem. The maf uses the stock electronics which were working fine 3 days ago. The vacume is a strong 20 inches of Hg on my boost gauge. Its just really wierd that it ran pretty good for not having a tune, then suddenly die. I changed the oil and saw no coolent in there. This is just really frustrating that it ran, and now doesnt.
 
#5
What brand maf are you using? You might check it to make sure it's still plugged in good, and there are no leaks around it. You might have knocked it loose if you were still working under the hood after it was running. I'd still say pull the codes though.
 
#6
Its a C&L. I dont know that I knocked it loose causing a leak or anything. The car ran for a good 20 mins, then just decided it didnt want to anymore. The PCV valve was out when i got it to the shop, but putting it back in didnt help. Im going to have to recheck the timing tomorrow. Once we force the engine to start, it revs pretty good, a little rough, but it does rev, and will even hang at 1200-1500 rpms, then just dies after a little.
 
#7
My PCV popped out once and I had no idea but I was at an intersection and the first car in line. I had to floor it several times to get it started then keep it running. After I got the PCV back in my plugs were fouled as hell from running so rich. I changed them and the car started running again. Lucky it was in my neighborhood for the test drive when it happened.
Couldn't hurt to just check them to see what they look like.
 
#8
It could be the maf. Mine just went out one day and i could only get the car started if i held the gas pedal at wot. then it would just die after that. Borrowed one from a friend and it started right up.
 
#10
Car now runs, after cleaning the spark plugs, but it runs horrible. It stutters, backfires, shakes, but it does idle for atleast 20 seconds. There is some coolant around the distributor though. Maybe the lower intake is leaking? I also think that i could just be running really really rich due to the 36lb injectors. I didnt see any coolant in the oil when i changed it yesterday though. Anyone have any more suggestions.
 
#11
Well really the only thing underneath the lower plenum is oil. Coolant by the dizzy would more likely be a leaky thermostat housing. Your lower might be leaking though, sounds like it's time to check for vacuum leaks. Get a can of carb cleaner (the spray kind) and while it's idling (may need a buddy to keep it idling while you do this) spray around where the lower intake meets the heads, where the upper intake meets the lower, your pcv grommet etc. etc.. If the idle raises you got a vacuum leak. It's possible that you're running to rich. What have you done as far as tuning with that s/c?
 
#13
DarkProphet said:
There is no tuning whatsoever. Its supposed to go tomarrow morning to get tuned, but im afraid to drive it there (40 min drive). Is it possible that running THAT rich will make it run that bad?
Click to expand...

I hope so, cus mine is running piss poor (drives okay, just running real rich and lacks the power it should have) and I've done everything short of a tune. Got my twEECer coming in tomorrow so hopefully that will clear some things up.
 
#15
DarkProphet said:
I took my pcv valve off again, and its FULL of oil, is this normal at all?
Click to expand...

It's pretty much a given that once you start modifying the engine, it's gonna suck a lot more oil through the pcv screen. That's why so many people run oil seperators, it keeps the oil out of the intake and thus out of the combustion chambers.
 
#16
silly question, but are your spark plug wire on right? i know it sounds stupid but i did it once before i switched my 5 and 6 spark plug wires, it ran, but crappy and it backfired and whatnot.... its understandable, putting stuff back together quickly because of a new mod or 2..... wouldnt hurt to check
 
#17
the sad thing is that my 5 and 6 plugs were backwards haha. BUT the plugs turned black in a matter of 20 minutes. I think i have a serious vacuum leak, most likely from the lower intake. I put new plugs in just now and it runs great, but i dont know for how long. What would cause oil around my distributor base and thermostat area? i was playing with timing, so is it possible for it to leak out of the distributor base? Also i have a light grey smoke comming from the exhaust, which isnt a good thing either...
 
#18
DarkProphet said:
the sad thing is that my 5 and 6 plugs were backwards haha. BUT the plugs turned black in a matter of 20 minutes. I think i have a serious vacuum leak, most likely from the lower intake. I put new plugs in just now and it runs great, but i dont know for how long. What would cause oil around my distributor base and thermostat area? i was playing with timing, so is it possible for it to leak out of the distributor base? Also i have a light grey smoke comming from the exhaust, which isnt a good thing either...
Click to expand...

Light grey? Is it almost white? White smoke (which is actually usually steam) coming from the exhaust is usually coolant in the combustion chambers. Caused either by a blown head gasket(s), or bad intake to head gasket(s).
 
#19
I just dumped the oil again, I see no coolant or water, (the seperate from the oil right?) The smoke is really like a light grey, and smells like oil or gas, more like gas, ill have to check it out once i refill with oil.

EDIT:
The smoke is a blueish, but went away after a min or so. The old oil has small bubbles in it, and when i take some and pour it back into itself, alot of bubbles form for a bit. does this mean i have water in my oil? i dont see any traces of coolant though, which is strange.
 
#20
95CobraMike said:
silly question, but are your spark plug wire on right? i know it sounds stupid but i did it once before i switched my 5 and 6 spark plug wires, it ran, but crappy and it backfired and whatnot.... its understandable, putting stuff back together quickly because of a new mod or 2..... wouldnt hurt to check
Click to expand...

:stupid: did it with # 2 and 3. same symptoms
 
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