having issues and getting fed up......

RedBirdSC

Registered User
i finnished going through the top end of my sc awhile ago, but since I'm in college i dont have much time to work on it now(that and I'm 2.5 hours from it). So I haven't been able to figure out its issues and its stumped my auto tech instructors, my dad, and I. So, take a stab at this... lol

Car info- no ce light, no upshift light when it cranks, takes about 30 seconds to fire. plugs(autolites) and wires(taylors) are new, cam and crank sensors are newer(30-40kmiles) o2's are just dangling(open headers-no exhaust at the moment). It also won't go into boost, bypass valvle slowly starts to open and the car stutters, but if i hold it closed for a sec, it'll stay idling after the rpms are bumped to about 2500 rpms.Another issues, its been inside the garage and outside for 2 yrs on a 1/4 of gas with no stabalizer.

I had the firing order switched on 1&3 and it held 12"s of vaccum, but ran like *** and sounds like it had a huge cam in it.So I fixed that, still sounds like it has a huge cam in it and it only holds 2" of vaccum. All ic tubes are sealed good, almost all vaccum lines are new, all have hose clamps on them. It doesn't rev smoothly, like it has 2-3 plug wires disconnected, but their all connected good.

I really want this car to run right as its my baby, but i don't have any other cash to spend on it really. It would make me feel a whole lot better if someone could give me some pointers. My instructors only advice was to have it towed here and check it out, but I cant afford that, plus I dont trust some of the theiving bastards in my class. So any and all help is GREATLY appreciated. Justin
 
you might want to make sure that the intake isnt clogged. a friend of mine had a tbird stored for a while and when to run it up one day and it ran like crap. so after a while of messing trying to figure out what was wrong with it he finally finds a birds nest in his air silencer. kinda far fetched, but it wont hurt to check. id also check the mafs and the fuel system. pump, injectors, fpr, etc. good luck.
 
Well my lower intake soaked in a parts washer for 3 days before i put it back in. The motor was torn down to a short block for about 6 months of it being down. So I'm pretty sure the intakes clear.

On thought the, the fuel pump was getting weak before the car blew the h/g's. i'll throw a mechanical gauge on it this weekend and see what kind of fuel pressure it has.
 
You have bad gas. Borrow a fuel system cleaning can for school, and fill it with gas, and turn off the pump, start the car it will run on the new gas fine I bet.


Tim
 
I'm thinking huge vacuum leak. Hit it wth some propane (or acetelyne) at the air inlet with the RPMs as steady as possible. If the RPM's take off then you know you're lean. Use the propane directed through a tube at each joint looking for that RPM increase again. Correct as necessary.
 
I didnt notice all these replys :eek: lol

Actualy going home this weekend, I'm going to drain all the gas out of it, change the filter, and clean the system then put some fresh gas in it. Then I'm going to cut up whats left of my old exhaust so I can mount the o2's again and give her a shot.

Pretty sure it doesnt have vaccum leaks, maybe a slight one here and there, but I already tested it with carb cleaner. Thats why I went through and resealed the ic tubes and put on all the new vaccum lines.

thanks for all the suggestions, Ill post an update monday night probably when i get back to school.

Justin
 
Be sure to check fuel pressure and bleeddown.
KOEO should be around 35 or so. KOER should be around 30.
Pressure bleed down (after they key is off) should be less than 5 PSI in 60 seconds, but if you are anywhere close to that, you have a bleed down problem.
 
No code reader so I dont have any codes but....

I switched out the gas for fresh 93, new filter, new battery

Still runs the same on 4cyl. Now it wont start..So I started thinking, took off my dis and had it tested, tested good. Car has good fuel pressure and everything. So maybe my coil packs took a dump? Is it normal for one side to fail, then all of them to die? Whats the easiest way to test these?( or what should they ohm at?) Thanks for all the help guys
 
Just something else to check.
You say you have 40,000 miles on the cam sensor.
I just had a new one fail at 45,000 miles.

Also, does your engine have a good ground to the frame?

Sure sounds like a vaccuum leak. :)
 
A vaccum leak wont keep a car from starting all the sudden. It WILL NOT start now.

Cam sensor throws a check engine light right? No up shift light, no ce light.

Never touched any of the grounds to the frame except for the motor mounts. It has new battery cables on it too.
 
coil gets good spark, pulled the spout connector and it sounded like it was burning the gas in my manifolds so i quit. Car will cough and sputter, but won't fire now thatall the wires were unplugged and pluged back in.

I had the dis tested at autozone and they said it was fine. Coils working. Has good fuel pressure. No air sucking sound that a vaccum leak big enough to keep a car from running.

Could it possibly be the crank sensor? The car seems like the timings way off or its not firing on all cylinders. So basicly whats the easiest way to check the crank sensor or is it one of the remove and switch and hope that was it kind of parts?

thanks, Justin
 
RedBirdSC said:
The car seems like the timings way off

Crank damper broken perhaps? This can cause all sorts of drivability problems. Been discussed here plenty so a search will turn up more info, like how to check it out.

As for the crank sensor, it's a Hall Effect switch which sends a digital (on-off) signal to the computer in the form of a square wave. You'd need an oscilloscope that'll read the 5vdc range to read it.
 
I grabbed the damper and tried to shake it when i had the motor torn down for hg's and it didnt budge. I did it a week or two ago too and it was still fine.

I think I'm going to try to replace the crank and cam sensors unless someone else has a better idea?.....

Thanks, Justin
 
Sweet90SC said:
reseal your IC tubes...Make sure you use a good sealant or the seal tape..


Or use T-Bird88's reuseable gaskets and be done with it. If you had the top off the SC you can reseal it with the copper silicone (thats what I used a year ago) but you should use a anearobic silicone (dries without direct contact to air).
 
The ic tubes are selaed with rubber orings along with silicone, their not the problem.

Even if they were leaking they WOULD NOT keep the car from firing, they've been off and resealed before by me and by a shop.

It is only trying to fire on 1-3 cylinders, otherwise it just cranks. It'll cough and sputter after about 20 seconds of cranking then it'll just crank.

It did run before, it won't run now. So it is NOT a vaccum leak.

Sorry to be a dick about it, but I know it doesn't have a vaccum leak. The ic tubes have been resealed twice, all the vaccum lines have hose clamps and have been tested with carb cleaner when it was running. But again, it won't start now, it is an ignition problem or timing problem. It has good fuel pressure, has spark at the coil, but it doesn't sound like its sparking or shooting fuel at the right time.
 
I had similar problems with a diffrent make of vehicle recently, but it ended up being the ECM was GOING FAULTY. (computer) So the car just acted real screwy when cold, also no CEL or any evidence of what the problem was. It was VERY frustrating testing every small sensor and to check for vacuum leaks, replacing what appeared faulty to no avail. Finally had to take it in for the pros to guess at it. Just a possibility.

Also, it sounds like your car/engine is incomplete as it is. Plus the gas issue, perhaps that BAD gas clogged your injectors and while you put new gas in only stirred up the crud in the tank plugging them more??? I'd drop the tank get it professionally cleaned, remove the injectors, test them and move along from there... old gas can do very bad things to a fuel injected engine.

Jim
 
So you are sure you have no vacuum leaks? :)

Are you sure the camshaft synchronizer is aligned properly? You may have it off a tooth.




Have checked the coil pack or DIS module?
 
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