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I've had my 1991 Camaro 305 TBI driving around for roughly a month. At the time I had all major issues fixed,and the engine was running great. Today I took it out to see how the handling improved after getting tires balanced. I was stopped at a 4 way stop,and the car died. I had no idea until I went and tried to turn the wheel and it wouldn't budge. At first it wouldn't even crank over,but I think that's cause I still had it drive (bad idea I know,but people were honking at me like crazy) or cause I had to turn the key off first. I got it to start,and got back on the highway. I suspected it was cause I was using my freshly charged and probably leaking air conditioning,so I shut it all off. I ended up stalling doing 65MPH in front of 18 wheeler,and I was sweating bullets trying to pull over. At that point I knew I couldn't trust the car,and took safest way home. I was about 3-4 miles away from home still,and I ended up stalling 3 more times (5 total on the road) before I got home. It started right back up every time aside from the first time. About a half hour later at home I started it up to swap spots with my brother,and it stalled in 5 seconds of being in park and just idling.
Before all this I rebuilt the throttle body,put in new injectors,new IAC valve,and new MAP sensor. Personally I'm leaning towards a bad fuel pump,but I'll wait to confirm that till I do a bit of trouble shooting for one. What else do you think it could be? How should I go about trouble shooting other stuff?
Also, I do not believe the IACV comes preset.
There is a procedure necessary.
It really should be reset during what is called the "Setting Minimum Idle Speed" procedure.
That procedure requires some sort of Digital Tachometer like you would find on a digital timing gun. An aftermarket digital tachometer gage installed would also work.
By the way, if its off, setting "Min. Idle Speed" is a very important thing to do. Its basically the foundation the ECM relies on.
Last edited by Ron U.S.M.C.; 03-12-2016 at 02:51 AM.
When my TBI pickup had stalling problems, it was the pickup coil on the distributor mainshaft. It finally died "forever", 250 miles from home. Chevy dealer installed a new main shaft in the distributor. A replacement distributor would be essentially the same.
Also, I do not believe the IACV comes preset.
There is a procedure necessary.
It really should be reset during what is called the "Setting Minimum Idle Speed" procedure.
That procedure requires some sort of Digital Tachometer like you would find on a digital timing gun. An aftermarket digital tachometer gage installed would also work.
By the way, if its off, setting "Min. Idle Speed" is a very important thing to do. Its basically the foundation the ECM relies on.
I've driven nearly 300 miles on the new IACV and never had an till now. Could that really be a problem?
When my TBI pickup had stalling problems, it was the pickup coil on the distributor mainshaft. It finally died "forever", 250 miles from home. Chevy dealer installed a new main shaft in the distributor. A replacement distributor would be essentially the same.
I don't know yet. I'll see if I could maybe rent a gauge at autozone or something.
Also, I do not believe the IACV comes preset.
There is a procedure necessary.
It really should be reset during what is called the "Setting Minimum Idle Speed" procedure.
That procedure requires some sort of Digital Tachometer like you would find on a digital timing gun. An aftermarket digital tachometer gage installed would also work.
By the way, if its off, setting "Min. Idle Speed" is a very important thing to do. Its basically the foundation the ECM relies on.
Just an update. I started it up today and I couldn't get it to stall. I could get it very close though by pressing the gas then releasing it quickly. Something new that it's never done before happened. I had it in park and idling. The RPMS went up and down from 650 to 800. It did this rather quickly too. I didn't have the A/C on,lights,radio,and the cooling fan wasn't on yet. The injectors seemed to be firing fine and giving a good pattern. I sprayed starting fluid in while it was idling and if I got just the right amount in it would rev up 250 RPM. I'm not totally sure what all this means. My guess is that,the computer isn't calculating air/fuel properly due to a freshly bad sensor or vacuum leak,the fuel pump is getting weak,or the filter is plugged.
Go to Harbor Freight and get a fuel pressure tester for $20 bucks. Or rent one from Autozone. This is a must have for troubleshooting fuel delivery problems. It helped find a bad FPR and get my bird running like a champ!
Go to Harbor Freight and get a fuel pressure tester for $20 bucks. Or rent one from Autozone. This is a must have for troubleshooting fuel delivery problems. It helped find a bad FPR and get my bird running like a champ!
It looks like I'll be going to harbor freight. Autozone doesn't rent them by me. When I get one where do I hook it to the fuel line?
Go to Harbor Freight and get a fuel pressure tester for $20 bucks. Or rent one from Autozone. This is a must have for troubleshooting fuel delivery problems. It helped find a bad FPR and get my bird running like a champ!
The harbor freight tester doesn't work on "GM throttle body systems" according to their site.
It worked on the V-6 schrader valve when I used it, so not sure.... But I read the 305 TBI doesn't have a valve. You have to tap into the fuel line with an adapter.
It worked on the V-6 schrader valve when I used it, so not sure.... But I read the 305 TBI doesn't have a valve. You have to tap into the fuel line with an adapter.
For God's sake! Everything on this car is such a pain in the ***. Well I'm a bit strapped for cash,so could I throw a soft fuel line over the opening of the hard line and hook the soft one up to the gauge? Or is the pressure just too much to handle that?
No "rail" with TBI. Fuel pressure in the 13psi range, give or take a couple.
So if I hooked up the gauge directly to the line I would see roughly 13 PSI on the fuel pump prime? Or am I just definitely going to have to get that adapter to test running pressure?
So if I hooked up the gauge directly to the line I would see roughly 13 PSI on the fuel pump prime? Or am I just definitely going to have to get that adapter to test running pressure?
How are you going to test "running" pressure if you have to disconnect the fuel tubing and install hose over it to test pressure?
Might as well get the proper adapter and do it the right way.
How are you going to test "running" pressure if you have to disconnect the fuel tubing and install hose over it to test pressure?
Might as well get the proper adapter and do it the right way.
That's why asked if I'd see 13 PSI on the pump prime or not. If I would NOT see 13 PSI on the prime;then I know I'd have to buy the adapter. My issue is the adapter costs $40 that I don't have,and I have to find a way to squeeze it inbetween the throttle body and that hard fuel line. When I rebuilt the TB I noticed how inflexible the line is,and how little room there is to bend it,so it'd be next to impossible to get the adapter in there.
Yep, that's the first I've seen of that design too. Not entirely handy having to hook up the gauge under the car, and you're not going to prop it between the hood and windshield to watch the pressure while you drive, but it would be easier to install, that's for sure.
Yep, that's the first I've seen of that design too. Not entirely handy having to hook up the gauge under the car, and you're not going to prop it between the hood and windshield to watch the pressure while you drive, but it would be easier to install, that's for sure.
Yea it should save me from braking my fuel line too.
Not entirely handy having to hook up the gauge under the car, and you're not going to prop it between the hood and windshield to watch the pressure while you drive, but it would be easier to install, that's for sure.
It's a flat-out pain in the azz. OTOH, it's the only way to access fuel pressure in some vehicles. Helps if you have a REALLY long hose on your fuel pressure testing gauge.
I would open the flex line between the chassis and engine to tap into. Even though the above is a nifty tool, I would be hesitate to remove the fuel filter and run the pump.
03-11-2016, 11:27 PM
