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I've been trying to figure out why it's not turning over for about a week now and need some troubleshooting advice.
For context I bought an 89 GTA with the 5.7 tpi in it. Previous owner said it hasn't been on the road in around 20 years.
Just replaced the fuel tank, pump, fuel filter, and fuel sending unit. When you turn the key the engine cranks but it never starts. I took the fuel hose off at the motor and fuel came out so it's getting to that point. Also the engine will fire on starter fluid but once the starter fluid is gone it just keeps cranking so it seems like a fuel issue to me.
I'm pretty inexperienced when it comes to fuel injected motors so any help would be much appreciated!
Update: Life's been really busy lately, sorry for the delay. I ended up getting new injectors and a fuel regulator from southbay fuel injectors and it fired up. It idles, not great, but it idles. Unfortunately though it looks like it's leaking coolant around the runners/intake manifold area so I'm probably gonna end up taking it apart again and putting new gaskets in. Coolant leak
Check fuel pressure, check injector pulse with a noid light. Ohm the injectors and write down what you get for each one. Even if they're electrically ok, they could be clogged or otherwise non-functional after 20 years.
Check fuel pressure, check injector pulse with a noid light. Ohm the injectors and write down what you get for each one. Even if they're electrically ok, they could be clogged or otherwise non-functional after 20 years.
Alright I'll check that out and see where I'm at. Appreciate the help!
Get a noid light for the injector harness.... Willing to bet that is fine though and those terrible multec injectors went bad. get some delphi injectors from southbay and do the regulator while you're in there.
Check fuel pressure, check injector pulse with a noid light. Ohm the injectors and write down what you get for each one. Even if they're electrically ok, they could be clogged or otherwise non-functional after 20 years.
Just checked the fuel pressure and it goes to 44 psi after turning the key to run then the pressure drops slowly. Maybe the pressure regulator is bad?
Slow drop is ok. Dropping to 0 like a rock is usually indicative of some sort of issue but the point is your fuel pump isn't bad. Move on to other tests.
For context I bought an 89 GTA with the 5.7 tpi in it. Previous owner said it hasn't been on the road in around 20 years.
X2 on the injectors. They're stuck and/or clogged. You can pull the fuel rails w/injectors, keep it hooked to the fuel lines and have someone crank then engine to prove the issue...have a fire extinguisher handy if you do that test.
Howdy…since this thread is pretty new, I’ve ran into a similar issue I’d appreciate some advice on. I have a 1989 Trans Am GTA 5.7
Threw a check engine light, was code 33. While it didn’t affect driving much I ran the car for a few months with the check engine light on. She ran well.
Coming home one day she just shut off going down the road. Engine would turn over but not start. I was getting fault code 33 and 36.
I finally then put a new MAF in but she still doesn’t start. After messing around with MAF relays and repairing a few wires I found needing repair. I was able to get it to start once and idle for 5 minutes… but then she died. who is it?
So I switched to troubleshooting fuel; with a pressure gauge I see about 42 psi when I turn the key on (and like the gentleman above it bleeds back down to zero ) she still cranks but no start. All injectors tested at 17 ohms.
I don’t want to start throwing parts at it as a troubleshooting method, appreciate any guidance or focused troubleshooting ideas.
Howdy…since this thread is pretty new, I’ve ran into a similar issue I’d appreciate some advice on. I have a 1989 Trans Am GTA 5.7
Threw a check engine light, was code 33. While it didn’t affect driving much I ran the car for a few months with the check engine light on. She ran well.
Coming home one day she just shut off going down the road. Engine would turn over but not start. I was getting fault code 33 and 36.
I finally then put a new MAF in but she still doesn’t start. After messing around with MAF relays and repairing a few wires I found needing repair. I was able to get it to start once and idle for 5 minutes… but then she died. who is it?
So I switched to troubleshooting fuel; with a pressure gauge I see about 42 psi when I turn the key on (and like the gentleman above it bleeds back down to zero ) she still cranks but no start. All injectors tested at 17 ohms.
I don’t want to start throwing parts at it as a troubleshooting method, appreciate any guidance or focused troubleshooting ideas.
Check for spark, verify injector pulse with a noid light. Is it still throwing codes?
Sounds like you need to get your hands on a scan tool that will show you data stream so you can see what's going on, what doesn't look right, and address that. But based on the earlier codes 33 and 36, AND the messing w/MAF wires and relays, it seems like the MAF is probably where you should focus your attention.
Update, tested injectors with noid tester—all good, they all lit up.
Fixed a wire at one of the MAF relays and she started.
But cannot take rpm’s past 1500 or engine starts sputtering to almost backfiring (more in the intake manifold than out the exhaust).
when she’s idling the RPM surge from like 600 to 1000 back-and-forth.
Good news is no more check engine light.
Sounds like you need to get your hands on a scan tool that will show you data stream so you can see what's going on, what doesn't look right, and address that. But based on the earlier codes 33 and 36, AND the messing w/MAF wires and relays....and more recent additional MAF wire-fixing which allowed it to run.....it seems like the MAF is probably where you should focus your attention.
Hopefully the intake gaskets will cure a vacuum leak and fix the idle issue.
FYI, If you spray that plenum, base and runners w/an aluminum etching product, such as "Eagle 1 Etching Mag wheel cleaner" (easy to get at most auto parts stores), then hit it with high pressure water to rinse, it'll look brand new afterward. Brand new.
Hopefully the intake gaskets will cure a vacuum leak and fix the idle issue.
FYI, If you spray that plenum, base and runners w/an aluminum etching product, such as "Eagle 1 Etching Mag wheel cleaner" (easy to get at most auto parts stores), then hit it with high pressure water to rinse, it'll look brand new afterward. Brand new.
Yea hopefully that will help the idle and coolant leak. Appreciate the tip about cleaning it because she looks pretty rough after 20 years lol.
I took the passenger side runner off and put new gaskets in. After putting everything back together and starting it was still leaking coolant. Turns out the hose that goes into the throttle body was leaking and dripping down to the bottom of the runners making it look like the coolant was coming from there. After tightening the hose clamp it stopped leaking.
It still has a rough idle jumping around from 500 rpm to 1200 rpm and it eventually will shut off after a few minutes or as soon as you give it throttle as shown in video.
We really cannot expect a MAF equipped engine to run properly with the throttle body intake bellows removed (as shown in the video).
The ECM will have no idea how to administer fuel to that.
That was the problem (imagine that lol). You can give it throttle now and it won't die instantly. Still idles like crap and shuts itself off eventually but it fixed the throttle problem.
Checked for air leaks around the runners and throttle body and it seemed fine. Fixed some of the vacuum lines they were in pretty rough shape. Still does the same thing, Starts up and idles around 800 - 1200 rpm then after about 30 seconds it idles down to 400 - 500 rpm. If you shut it off and start it back up it will do the exact same thing. Idles around 800 - 1200 then drops down after about the same amount of time.
I will have to check the vacuum lines more throughly when I get some time.
10-10-2023, 10:15 PM
