slow_90firebird

Alright, I have made multiple threads in the TBI section about this problem, and nobody seems to be able to help me. Either nobody replies, or they arent really able to help me diagnose this problem. I know there are people on this site with in-depth knowledge of how these engines work, so I was hoping somebody can help me out. I am on a budget of $20 to $50 and need this to be reliable (its my daily driver).

Alright, here is my best description of the problem. It seems to be related to both engine temperature, and weather (rain=stranded on road). What happens is, on a nice day when the car is cold, it will run perfect and drive great. Now, my thermostat is stuck open, so the car will barely warm up if I am moving (highway). But red lights and such are bad news, because it allows the car to get into closed loop. As the car starts to get warmer, it will start to backfire and lock up the rear wheels whenever I try to accellerate to pass or speed up. It still cruises fine. However, if the guage gets to like 1/4 warm, it will backfire all the time. Almost undrivable.

Now, if it is raining, it is 100 times worse. It will get worse and worse as I keep driving, no matter what the temperature. However, as the temperature goes up, it gets horrible. Tonight I barely made it back to school, parked, and let it idle. As the temperature approached 180-200, it was missing at idle. And any tiny amount of gas would stall the motor. Finally, just before 220 it wouldnt start anymore. I have taken off the aircleaner and this is what happens out my TBI when I rev it up. Or sometimes a big purple flame comes out one of the bores! http://www.youtube.com/watch?v=5rkp2lzGf2A

The other day it was so bad the motor stopped in traffic as I was turning into the doctors office. I almost got pancaked, except I restarted the motor by feathering the gas and then slipped the clutch to barely get me out of traffic. I pushed the clutch in and it stalled at idle again and I coasted to the parking spot. I came out of the doctors and the car was still warm. It didnt want to start, and if it did, it wouldnt idle at all. So instead of call AAA I took off the aircleaner and pulled that big vacuum hose off the TB that goes to the MAP sensor. Then, when I tried to start it, it poured fuel and sounded like it was running on 3 or 4 cylinders (and smoked). After about 10 seconds, the injecotrs leaned out, and the SES light came on. It ran good enough to get me home (but still backfired alot). Replaced the coolant temp sensor to migman's suggestion, but no difference.

Also, the problem has been getting worse for the last 3 months. The injectors have a perfect cone, and the base timing is 0*. I dont think its the fuel pump because it runs perfect on a cold morning, so it must get plenty of fuel? Oh, also the edges of my throttle blades have turned black with charcoal over the past few weeks. I cleaned them, but it came back after the next rainy day. I think it is from all those purple and blue flames that keep coming out the TB.

Any help would be appreciated. I am a broke college student in need of transportation. That is why I cant just start replacing random stuff. Maybe there is someone in the nashua, NH area willing to help a buddy troubleshoot this problem so I can know what I need to fix.

88transam400tpi

i would check out your ignition parts cap rotor and have the ign module tested

slow_90firebird

Well, I have looked and I cant figure out how water would get in the cap. There are no cracks or anything. However, what does the ign module do? Is it like a computer or something?

Also, why would it be fine some days and bad others?

Toehead

Ignition module sends the RPM reference pulses to the ECM so it knows the engine rpm and when to trigger the coil.


When the car is missing, does the tach flutter rapily between zero and some reading? That is a dead ringer for a bad IGN module.

The problem with rain leads me to believe it is an ignition problem...

kurfbird

iTrader: (24)

I would replace the cap and rotor. I had one that was cracked but you could not see it.

Get a chiltons or hanes or factory serive manual. I have afacotry service manual and have made up my money.

Check plugs and wires use ohm meter on plug wires and check plugs for gap.

Replace Pick up coil 15.00

Replace igniton module 35.00 These can be tested at a store but still be bad. They dont get warm enought at a store but will be bad.

Replace coil.

Your car is 17 years old and could probably need all these items.

slow_90firebird

Well, I have never worked on a car with a distributor before, this is my first. How hard is it to remove, and do all that stuff? Especially the coil, since you mentioned that heat could affect the operation of it.

The tach doesent jump all over, but when the car is backfiring you can see the needle drop a little as the wheels lock up (its a stick so it bucks).

As for the plugs, I replaced them with rapidfire's 3 days after I bought the car.

The cap and rotor, could be origional factory. I got the car with 47k on it and cant really find any sign of work done to it besides the new (kelly charger ) tires, and oil change sticker in the window.

The wires say "packard" on them, and each one is labeled with its cylinder number, kinda cool. So I figure those are newer. They do have a little rust inside the boots, but not too bad to cause a miss.

Finally, how come this will never trigger a SES light? I mean, the car can barely be chugging along, and the light wont come on untill the motor stops.Isnt the ECM supposed to monitor this ****?

Thanks!

Toehead

It's OBDI, it doesnt monitor as many things as the newer system.

The ignition components are very easy to change. The distributor cap comes of with two screws. The coil is rivited on.. Drill the rivets and replace them with screws. The Module is under the cap and is held on by 2 5.5 mm screws.

kurfbird

iTrader: (24)

The computers on these car S*&K as far as iam concerned. They basically can run like Cr&p and still wont throw a code.

So the plugs are done.

I would bet the that the plug wires are orginal. Test them to be sure that they are not going bad.

Replace the igniton module. Easy to do take off distibutor cap looks like a peice of plastic that has two screws that bolt to the distributor. Has a small plug that is you pick up coil. Be careful I have replaced the ingiton module and messed up the pick up coil in the process.

Coil is hard to describe. It is the one plug like wire that comes from your distributor. Easy to replace. As long as you ahve some hand tools.

slow_90firebird

Ok so I dont need to pull the whole distributor to take the module and stuff out? Thats what the haynes book said to do, but I dont want to mess up the timing gear. Also, I tried to advance the timing for power a while ago, and couldnt get the dizzy bolt loose. I even got that special wrench from auto zone, and it started to kinda strip the head on the bolt.

Toehead

Nope, the module is easy to change. Just take off the cap.

kurfbird

iTrader: (24)

You will have to pull the distributor to replace he pick up coil. SO let hope its not that

slow_90firebird

It has to be an ignition problem I am almost convinced now. To make things worse, I have that formula hood with the block-off plate, but it leaks water right all over the cap and wires. That probably doesnt help things.

Is it normal for this stuff to go bad even if it doesent have alot of miles? Also, is engine temperature a determining factor like I think?

Finally, once when it was acting up I disconnected the ESC weatherpack connector, so it was running base timing. This just made it run worse.

Toehead

Ignition modules tend to act up the most when they get hot.

slow_90firebird

Well, I have been searching around here in between posting, and found that everyone says to get a delco module, not accel or something.

Looks like I should find somewhere around that carries AC Delco parts.

Also, will autozone or someone "test" the module first? If I can determine solid that it is bad, I will be less reluctant to spend money I dont have.

sofakingdom

iTrader: (1)

Sounds like a fuel delivery issue. Spiting back into the intake = EXTREME lean condition.

What is the fuel pressure WHILE IT'S SCREWING UP? (Duct tape your gauge to the windshield, drive around, make it do its thing, get a reading WHILE IT'S SCREWING UP)

Doesn't sound like the ignition module to me. Flames in intake = you have spark just fine, not a no-spark problem.

Yes you can have it "tested". Problem is, the conditions under which it's "tested", don't replicate the conditions under which the car malfunctions.

slow_90firebird

There isnt a schrader valve on the TBI cars is there? I was told that you need somethng that goes in place of the fuel filter. I did replace the fuel filter, but it took me a few hours and I lost like 2 gallons of gas in a big drain pan. I really dont want to mess with that again if I dont have too.

There is no way that having the timing screwed up could cause a backfire?

Another thing is, that if its idling and its a "bad time" for the car, if you were to apply like 1/4 throttle all at once, it would stumble, backfire, shake, and then smooth right back out when it got to the higher RPM and stay there.

Finally, what in the fuel system could be affected by temperature or moisture? And also, when the problem is happening, the exhaust smells extremely rich - and under the hood smells like raw gasoline because the backfires.

kurfbird

iTrader: (24)

Right there is no sharder on a TBI car. I dont think its timing because it would always be messed up not just when it got warm

royslsbry

get someone to help you

royslsbry

your best bet is to take it to a shop and have it checked out there are numerous things that could cause your problems get someone with some experience to chek it out it cost a lot of money making guess and changing parts it better to pay some to fix it the first

Toehead

Where's the fun in that?

My belief is that you can do it yourself if you approach it logically. The reason I thought it was ignition is because the high voltage is very prone to moisture.

It could also be fuel related, but I am still leaning towards ignition.

archemedes

the modules are cheap I just replace them as the tester is only about 20% accurate, and I like to have spares anyway. A hot engine miss is usually a bad module (when at the dealership we just put a module in with no testing because of how common it was)

slow_90firebird

How much does a AC Delco module go for? I cant find any OEM ones on autozone's site.

Also, maybe not important, but the first EVER time this happened to me, was when I sprayed the engine bay for a while with the garden hose. I didnt think anything needed to be covered up. Also, I rinsed it without the motor running, after I had washed the car.

Before that day, it always ran perfect rain or shine, hot or cold. Then, it started acting up on heavy rain days, or whenever I washed the car. Now it does it all the time (at least 75% of the times I take the car out) to some extent. And it is temperature sensitive.

Also, the rich exhaust smell makes me hope that there is raw gas being dumped due to bad, or off time spark.

Finally, would a bad module show up if I aimed the timing light at the balancer? Like is it normal for the mark to jerk around with changes in RPM or should it move around smoothely?


Oh, thanks for helping me out everyone. I am glad that you guys could help give me some ideas for stuff to check for. Im sure you know that pissed feeling you get when you have to limp home in a car barely running on the shoulder of the road.

cooter26

iTrader: (1)

Yea that (problem didnt start untill i sprayed it with a hose) part would have saved a lot of replies. It is definitely your ignition system. jsut buy the cheapest module at autozone with your $ situation it will be fine. With your skill level (not being mean) do not take your distrubutor out with out a book and compitent help. You will never get it back running. You might even be able to take the distributor cap off and wipe it out, clean the contacts with sandpaper. Make sure you did put the plug wires back on correctly. We have (at least i have) done these mistakes before, great learning experiance, but not on your only car. There has to be someone on this website in your area.
Good Luck and take it slow 1 thing at a time that way if you mess it up you know what it was.

slow_90firebird

well, like I said, all my plug wires are numbered so that makes putting the cap on a little easier. I should be able to get the cap off no prob. But I need to find a sharp screwdriver that will dig in (i have a screw on cap). The 2 little screws that hold the cap on are really rusted and wanted to strip last time I tried to take the cap off.

Also, can autozone or anywhere test the ign module while it is in the car? Or do I need to remove it? Looks like I might be taking the cap off in the AZ parking lot!

And how would spraying it with a hose really mess anything up? I mean, unless the cap is cracked, I dont see how water would get in there. Doesent the cap have a seal on the bottom where it seals against the distributor base? And would water cause a module to prematurely fail?

cooter26

iTrader: (1)

Believe me water can and will get in there. Even a small crack can let enough moisture in to mess things up, i believe they can test it on the car. But a store brand set of wires, and a new cap and rotor shouldnt be that much and with gas at over $3 a gallon you will make it back in a month or so. Plug your timing connector back in and pull the plugs and clean them.

slow_90firebird

Well the car was running like absolute **** today (it rained all day). I couldnt get to autozone. I decided to try what you said about pulling the ESC connector on that tan wire. Doing that made it like 10 times worse. It was backfiring so much that it couldnt get past 2500 RPM in neutral.

I took two real low quality cell phone videos, if you listen you can hear the backfires on the tachometer video, and hear the whole car shudder on the stick shaking video.

http://www.youtube.com/watch?v=IK2TicDfaLQ

http://www.youtube.com/watch?v=5Y-HmvFPdwg

Toehead

You're in nashua NH?

The tach video does not look like a module to me. When my module went the tach went crazy.

Have you opened the hood at night yet? Look for lightning.

I would also pull the cap and see how bad the contacts on the cap and rotor are.

EDIT-
If you are still having problems this weekend I'll be in the area. (townsend)

slow_90firebird

Well maybe the module is still good then! Because those are expensive. However, would a little water getting inside the cap cause this serious of problems? Since you watched the video you could probably hear the backfire, and see how violently the car was shaking.

Interestingly enough, I went back out just 1/2 hour ago for a smoke, and I decided to start the car. It revved up perfectly smooth. So I went to walmart on amherst st. The only time it acted up was when I tried to pass a rig on the way back. But the temp guage was a little warm, so it does this even on dry days.

Lastly, has anyone used a Hypertech cap and rotor? Pepboy's site has that for my car. Also, autozone's site has a "gold brand" cap and rotor that is bright orange and has brass contacts. Looks almost like a MSD. They are both reasonably priced. The cap on there now has silver contacts with white oxidation that comes back even after I sanded it off.

Oh, and what place sells the "packard" wires like I have? I like the way they are individually numbered, and they look like they might have been a quality wire 10 years ago.

zipfast

iTrader: (2)

Use the one with the Brass contacts.
The packard wires are factory GM and the replacements probally will not be marked.

slow_90firebird

Wait, so your saying that the wires on my car are like 18 years old? I figured they were newer just because factory wires wouldnt last that long. That means if the previous owners never replaced the wires, the cap and rotor might be origional too!

zipfast

iTrader: (2)

I did not check your specs to see how many miles was on it (you didn't state it either).
I have seen cars come in for a tune up with +100,000 miles and everything was orginal. Then others with 40-50k that needed everything too.