Hi I just bought a 89 trans am GTA 5.7 v8 and i need some help fixing it up. It has a couple of problems that I cant figure out along with some wires that aren't connected to anything. The problem is that after the car is started it will often bog out and then it wont start for like 15mins to an 1 hour but after that it starts back up fine.I also noticed that sometimes gas leaks out near the tank (I don't think the tank has a hole in it). My friend says replacing the fuel pump will solve both problems so I'm looking for opinions. Also the temp gauge doesn't seem to be doing anything even after the car has been running for awhile.

The wiring issue I have is that two different wires coming up from under the engine are not connected to anything (one is almost broken off and the other has no plastic connector). First picture shows these wires. Picture two is a chewed up looking wire under the the upper throttle-body piece. I'm not sure if its affecting anything.

Also the check engine light is on and I plan to scan the error codes but Ide like to figure out whats up with the wire in pic 2 so I can reassemble the throttle-body first. If someone knows how i can solve any of these problems I would greatly appreciate it.

 

I think I can help with the first picture. There are 2 singe-wire connectors coming out of the same loom. One black (connector butchered) and one white (connector looks OK).

Those would be your knock sensor (single black wire with the butchered connector) and your secondary fan temp switch (single white wire), if memory serves.

You can see where they are supposed to plug in from underneat the car. Knock sensor will be along the pass. side oil pan rail just above and in front of the starter. The secondary fan temp switch will be screwed into the pass. side cylinder head between the rear two spark plugs. The connectors on those two wires should be the same, except for the difference in color. The color of the wire and connector will match the color of the plastic nipple on the sensor they are supposed to plug into (you can plug them into the wrong sensor but the color coding will guide you which one should be where).

I JUST RECENTLY had to figure those exact same two wires out on an 87 GTA, which is why this is fresh in my memory. You can look up my thread in the cooling system section of the board from about a month ago, if you want.

The second picture looks like the EGR temp sensor to me (which gives feedback to the ECM about whether the EGR valve is actually opening and flowing hot exhaust gasses when commanded by the ECM).

 

If the fuel pump runs, then no need to replace - they either work or they don't. Fuel pump would have nothing to do with a gas leak.

If your car is leaking at the rear, chances are you have a break in the filler tube. That seems to be a common problem with these cars - the filler tube is welded to the tank, and they tend to break at the weld - see if the car still leaks fuel when the gas is low or only when over 1/2 full.

How long after it's started does it "bog down"? Is it only after it gets up to operating temp? Might be a bad Ignition Control Module if it only happens after car gets warm - this is inside the distributor, under the rotor. They get hot and since it's electronic it tends to stop working with the heat. They are about $35 any auto parts store, and I think there's a method for testing them but not sure.

 

I only drove it once after i bought it and it bogged out about after only a half mile, then it wouldn't start. After I got it towed home it started right up again and i let it sit and idle for like 10 mins in which nothing happened. after I shut it off it wouldn't start again just like before. I'm thinking maybe the fuel pump is overheating?

 

When this happened, could you hear the fuel pump prime when you attempted to restart the car?

Again - could you hear the fuel pump prime?

What happens if you go outside and crank it now? If it cranks and runs, see if you can recreate the scenerio = let it run 10 minutes or so, watch the guages for overheating and such, shut it off, and try to restart and see if the fuel pump primes again.

 

I can't do that right now cause i have the throttle-body and valve covers off. Also the temp gauge currently doesn't work

 

I'm still trying to figure out if that wire in picture 2 is important and if I should replace it.

 

Have you checked the fuel filter?

 

No I dont know where it is im new at all this and still learning. could a filter really be causing my stalling and starting problem?

 

Anything is possible - replace the filter - alot of these cars are still running the original filter somehow. It's like $10, takes 20 minutes. Get yourself a can of PB Blaster too - spray the ends of the old filter with it and wait 10 minutes - makes a world of difference getting bolts loose - don't waste time with WD-40, it's useless.

If possible do this on an incline where the rear end is higher. Get the rear jacked up or on ramps. You have TPI - so 1st open the gas cap to release pressure. Next, get a rag, hold it over the schraeder valve (like a tire stem) on the fuel rail, and take a screwdriver tip and depress the button inside - this will release the pressure in the lines. The rag is for the gas that will escape - so do this on a cool motor, no smoking. Then crawl under the rear, on the driver side about 1 foot inboard from the car side just in front of the rear tire is the fuel filter - about the size of a beer can. Spray ends with PB Blaster, go have a smoke and a drink, then remove. Have a big towel or several rags with you, it will still leak gas - watch the eyes. Replace, make sure to use BOTH wrench sizes so that you don't strip the ends out. Also don't force it, if it seems stuck, spray again with the PB Blaster, come back in an hour. If still seems stuck, spray again, and try again tomorrow - the longer the PB has to work, the easier. Car back down, gas cap back on, good to go.

It's a good idea to replace this about every 2 years.

Oh - the wire - yes I would, especially if it looks like it's not making good contact - or at least if it's still making good contact then get it shrink wrapped.

 

I read a couple of articles online and one of them about fuel pumps matches my stalling and not starting problem almost perfectly. problems are
1. Fuel leak near tank
2. Car stalls after warming up and wont restart for some time.
I think that I'm going to get a new fuel pump

The last couple of problems I have are
1. Temperature gauge doesn't work.
2. Messed up wires in the two pictures. I think the black one is the knock sensor(do i need to fix it/how should I go about it) and the white one is the secondary fan temp switch. (please correct me if i'm wrong on either of these. I was told the chewed up black one in pic 2 was the EGR temp sensor and Im wondering if I should fix it as i looked at it earlier and a couple of the tiny copper wires are cut from each other. I really want to get this car fixed up and back on the road I just require a little more help than most of you guys since I'm new at everything and still learning.

 

I still have no idea what a leak at the tank has to do with a bad fuel pump pump is literally inside the tank, the only way the tank can leak is if it has a hole - which has NOTHING to do with a fuel pump It's like saying my tequila bottle leaks because the worm is dead!

You said the pump runs if you put 12v to it, but I guess that rubber hose at the top or the bottom of the pump could have melted into goo as it does for alot of folks. Won't take anything but time to do it, the pumps are pretty cheap (~$60 stock). Make sure to get a new 'sock' for the end as it won't come with one. And get a good quality, like AC/Delco or one from Napa - this job is a PITA, you don't want to skimp on a cheap pump, especially if you are dropping the tank instead of cutting the access hole. In your case, dropping the tank might be better, help you trace that leak.

I'd still do the fuel filter as well, and fix those wires for sure. You can get a new connector at stealership for the one, or yank one at the JY.

 

Your probably right but for my sake I hope not cause I dont want to replace the tank cause of leaking. I'm going to replace the fuel pump and check for leaks we will see how things turn out. And yes I plan to fix those wires but I still want to know more about them cause Im trying to determine why my temp gauge isnt working and Im wondering if any of those wires have anything to do with it.

 

Once you have the tank out - if it does have a leak in it, that can be fixed. They make a putty that can fix a gas leak, trick it to get the area clean and scuffed good so the putty has something to adhere to. Or you can have someone weld the leaking spot - it just has to be empty of course, and have the fumes evacuated.

Those wires shown above wouldn't have anything to do with your temp guage. Sorry no one's answered that issue yet - we were working on the big stuff for you first and forgot about the temp guage issue. Anyway, 1st thing I'd try is the replace the sender - it's on the driver side head, between #1 and #3 spark plug and has a single wire to it with a standard spade connector. I'd remove it BEFORE I went to the auto parts store and take it with me - there are several different temp senders depending on model and such, and most of the time the idiots at the parts counter give you the wrong one the first time

If that doesn't fix it, then maybe the guage is bad - not an everyday problem but it does happen.

Good luck with the tank job! You'll need to get the rear of the car on jackstands as high in the air as you can - nose needs to be touching the driveway almost. Put the jackstands under the car just in front of the rear lower control arms on the body framerails. You'll get to a point where it seems like the filler neck will not allow you to remove the tank - when you get there, get the neck slightly wedged, and then very gently using even pressure you'll have to slightly bend the filler neck just a wee bit in order to wiggle the tank the rest of the way out.

 

well that sounds like a whole bunch of fun......i have the same leaking problem but it only happens when i top it off so its either the pump o-ring or the filler neck grommet. i also think im losing pressure going from fuel pump to hard lines......(that melting hose problem) so i would agree with everyone you may as well drop the tank and give everything a real good looking over.......hope she comes out running strong..

also how much would it be to get the tank welded if it is the tank itself leaking.....cause a new tank is 167 bucks......sooooo???

 

I'd think any normal Joe welder would be happy to fix a small tank leak for $20. I'd ask around at like a small 1-man muffler shop or radiator shop. Those kinda guys LOVE cash, Uncle Sam can't tax it!

 

you aint lyin....i had a machine shop in alvin,tx called R.P.M. (Rolands Precision Machining) press my bearings (accord so they are pressed in to steering knuckle) press the ball joints in the lower and upper control arms, install new bushings on the upper control arm and do the studs that pep boys decided to cross-thread(every single one on right tire broke off lol)
for lik 35 even. i mean i realize thats not 'hard' work in any way...but when you dont have the equip. to do that kind of stuff it really helps.....sorry lol