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Let's, please, get a TBI car running again, if you don't mind....

vandelay industries

vandelay industries

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The first problem is that the car was sitting for at least 3.5 years and when i went to try to crank it this morning, the starter did kick for a second, but now we've lost ALL electrical power as if there's no battery. Battery is good though.

Previous to that about 2 years ago at least it would crank, but no fuel pump, which, now that i think about it, this may be related to above, but one step at a time.

NOTE: 1) i can provide pictures AND scan in anything from the service manual----i just don't quite know how to "read" the service manual/diagrams.
2) My electrical knowledge/ability is not that good, but i'm willing to learn.

90 cavalier 4 cyl.
 
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Usually the battery cables need a good scraping with a knife or file to get the lead oxide off them that grew while sitting a long time..
A wire brush may make them look shiny,but the layer of oxidation has to be removed before a sufficient amps will be able to reach the starter..

First thing we did at the junkyard when something just went click and wouldn't crank,was do that to the cables,8 out of 10 times that would get them cranking..if not,we'd hook up a remote start push button to the solenoid ..usually they would crank then...

It would be wise to inspect as much of the wiring for damage as suggested--frigging mice & chipmonks could have eaten the insulation or cut some in half..

I've seen a few starters at the junkyard that were filled full of seed & nut shells ,packed so tight the starter couldn't move the bendix out,or spin over ..one car had the entire bell housing packed with insulation from under the carpets so tightly it bound up the torque converter,engine wouldn't turn until we took off the dust cover and used a pry bar on the flywheel to get it to move--once most of the crud fell out it started cranking normally!..
 
vandelay industries said:
The first problem is that the car was sitting for at least 3.5 years and when i went to try to crank it this morning, the starter did kick for a second, but now we've lost ALL electrical power as if there's no battery. Battery is good though.

Previous to that about 2 years ago at least it would crank, but no fuel pump, which, now that i think about it, this may be related to above, but one step at a time.

NOTE: 1) i can provide pictures AND scan in anything from the service manual----i just don't quite know how to "read" the service manual/diagrams.
2) My electrical knowledge/ability is not that good, but i'm willing to learn.

90 cavalier 4 cyl.
Click to expand...

you sure the battery is good? Sitting for years will kill them. It may have some juice left, just not enough to do much.
 
You need a multimeter. There are alternatives (test light) but a multimeter is useful all around the house.

First thing I'd do if I thought the battery was good, is to put the multimeter on the battery terminals, and watch the voltage as I tried to crank it. A bad battery can show 12V+, but have zero storage capacity...they will drop voltage as soon as a load is put on them.
 
The battery is good at 12.58 V. and it came out of the truck, which, as you probably know , also doesn't run due to the trans. But i've gone a month without a car(NEVER again) and almost at the end of the rope so to speak. i know how things work----as soon as i start working on this car, the shop will call saying that the trans is ready.......

i do have a multimeter, but don't know how to use it; (they are like holley carbs----they don't come with instructions....) For all practical purposes and for the sake of this thread, let's just say i don't no nothing about electricity and you'll have to teach it to me like i'm 5 years old or something.

Remember, i can't crank----no electrical power to the car whatsoever after cranking for a split-second yesterday.
 
meter not for you? buy a test light, $8.. put it on the grd and start following your power.. first place to check is down at the main lug on the starter..
 
OK, I'm lying here bored and in some small physical distress, so I need to take my mind off things. This should just fill the bill.

If everything is dead, that is actually a good thing. Makes finding the problem easy.
Here are the steps you need to take. Do these, and you will find the problem or isolate it at least.
Do them in order, even if they don't make sense.
First, turn on the headlights, and see if they work. If they do, stop and let me know before going farther, the tests need to be modified. If they do not work, Leave Them On. That is important.
If the headlights do not work, do the following:
Set your meter on the lowest number above 12 volts DC. Probably 20 volts. If you are not sure how to do that, or how to make sure its set on DC, post a picture of the front of the meter, and I'll tell you how to do it.
Then, put the positive (red) lead on the positive battery POST. I assume you have the "old style" battery with the top lead post. If so, make sure you put the probe on the top of the post its self, not the clamp.
Put the negative (black) lead on the negative battery post. You should read something above 12 volts. If not, stop and we need to do something to the battery. This test tests both the battery, and the meter settings. I know you said the battery was good, but that was a little while ago. When doing a series of tests like these, never assume anything. Test it all.
When doing all these tests, make sure the probes are making good contact. If on a battery post, make sure its digging in to the lead some.

If you have 12 volts or above, take the negative lead off the negative post, and put it on the positive battery clamp, leaving the positive lead on the positive post.
I know that sounds stupid, measuring the same post, but trust me, it makes sense.
You should read 0 volts. If you read pretty much any voltage in any of the next tests, you have found a problem, let me know.
If you get 0 volts, take the negative probe off the clamp, and stick it down through the insulation of the positive wire past the positive clamp.
Again, you should read 0 volts.
Now, remove the lead from the positive battery post. Put the negative probe on the negative battery post.
Gonna take a short cut here, should not do it, but its makes it easier.
With the negative probe on the negative post, put the positive probe on a clean piece of metal that is part of the car engine or frame. Alternator housing is good if available.
Try several places, digging the probe in to make sure it makes good contact.
If you get 0 volts everywhere, let me know, we will have to do more tests.
If you get voltage on any of these tests except for the first battery test, probably full battery voltage, we have found the problem, let me know where you got the voltage, and I will tell you what to fix.
 
i'm a dumbass (this should be obvious by now....): Yesterday morning when i first whipped the battery in there, it was dark. So, i ASSumed the cables were good. After i thought about it some more, and read various advices, i looked at the cables again. This time WITH LIGHT. They were really bad----the car hasn't run since 2013. i cleaned the cables with baking soda, wire brush etc.

Now i have power and cranking. But now we're at the next step-----which is where i was 3.5 years ago-----NO FUEL PUMP. i should say, you may or may not know, but when you turn the key towards start on a TBI car, you should hear the fuel pump for 2-3 secs. i don't have that and the engine won't start but will crank.

What to do next?

P.S. Thank you Fordum and everyone else. Please stay with me.
 
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Quick and dirty test.
Got a propane torch and someone to help?
Take the air cleaner cover off, turn the torch on, DO NOT light it, no matter how tempting it might be, point it down the throat of the throttle body and have someone try to crank the car.
Looking down the the throttle body while doing this is not considered a good idea if you like your eyebrows.
The engine should try to start or maybe even start and run at idle. If so, the ignition system is working, and its narrowed down to the fuel.
Note: On some vehicles, the ignition module also controls the activation of the injectors, and you can sometimes get spark but no fuel due to a partial failure of the ignition module.
At this point, especially if it will try to start on propane, I would go straight to the fuse box and start examining the fuses. It might not be a fuse labeled fuel pump, it might be something that seems completely unrelated, so check all the fuses with a strong light so you can see the element in there.
Pull any that looks even a little suspicious and either look closer at them, or use your meter set on "ohms" to see it its good. Ask if you need instructions for the setting.
DO NOT use the meter on ohms to test a fuse in the box. Remove it first. And turn the ohms function off as soon as you are through with it. Hooking the meter up to a connection with any voltage will blow the meter.
Easy to do if you set the meter down with it on ohms and pick it up later.
No torch? Go to the filler hole, take the cap off, and put your ear next to the hole while some one turns the key from off to run. Sometimes you cannot hear a really quiet pump from outside.
If all the fuses show good, you may be looking at a new pump. Sitting in old gas that long may have done it in.
Another quick and dirty idea, get something like a rubber hammer, slide under the car, and whang on the bottom of the fuel tank while someone cranks it. I have gotten many folks home from the woods with a bad fuel pump that way.
A bad bearing or a piece of dirt can cause the pump to not be able to start, but jarring it while its under power often lets it start. Once started, it will usually keep running until you shut it off.
But then will usually not start again.
 
If the cable ends were bad then more than likely the wire inside the cable is corroded also leading to increased resistance and future electrical problems. Might want to just buy new quality cables.

Here’s what I’d do. First is to check the fuel pump. Most will say to use the jumper wire for the relay under the hood, but to rule out any wiring/relay issues I run 12V to the unplugged pigtail at the gas tank. You could even use a 9V battery if you want, I’ve done it and it runs the pump just fine as long as it’s a fresh/strong battery. The grey wire is 12v to the fuel pump (purple wire is for the sending unit so ignore that). For ground scrape away the protective coating on the gas tank to get down to bare metal. The lip in the middle of the tank is best so you don’t need to worry about rust holes forming. So 12V to grey wire and ground to bare metal. Do not rely on the ground wire that’s there since it may be bad, that’s why I want you to use your own. Should hear the pump run. Once we know the results we can go from there.
 
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1988 K5 blazer - original 350tbi

Man, I normally don't post but I couldn't pass this one up. I had a no start condition. At first I thought it was a fuel pump so I removed the line to the TBI and fuel came out like a water hose. Then I thought maybe it was the regulator in the throttle body even thought the throttle body was brand new, so I tested for spark at the injectors....no spark. Here is a list of the things I changed trying to get my truck to start, and I may be forgetting a few:

Throttle position sensor, temp sensor, distributor cap and rotor, coil pack, all new wiring and grounds, ignition control module, oil pressure sensor, ECM, fuel pump relay, eprom chips, throttle body, full re-wire. Still no spark at the injectors.

All of that work and looking online I have realized how crappy and fragile the TBI system is and when something goes wrong, it really goes wrong. I have read some instances, like mine, where nothing has fixed the vehicle and people just swap to a carb.

I know the TBI vs Carb argument is alive and well and I was always a big TBI proponent just because of the self tuning aspect and it seemed simpler. Now after realizing how many different components can affect a no spark condition and how difficult it is to properly troubleshoot it, I think its garbage. The wiring itself is completely insane and most shops in my area won't even touch the thing unless I am willing to shell out a lot of money just for trouble shooting.

I am finally done with this thing. I just purchased a turn key Ls3 with a 4L70E. I realized I really like this truck and I was fine with the 350TBI but am no longer willing to invest time and wasted money on the motor. So happy I made the decision and cannot wait until it is installed.

Good luck, I hope you have better luck than I did.
 
Fordum said:
Quick and dirty test.
Got a propane torch and someone to help?
Take the air cleaner cover off, turn the torch on, DO NOT light it, no matter how tempting it might be, point it down the throat of the throttle body and have someone try to crank the car.
Looking down the the throttle body while doing this is not considered a good idea if you like your eyebrows.
The engine should try to start or maybe even start and run at idle. If so, the ignition system is working, and its narrowed down to the fuel.
Note: On some vehicles, the ignition module also controls the activation of the injectors, and you can sometimes get spark but no fuel due to a partial failure of the ignition module.
At this point, especially if it will try to start on propane, I would go straight to the fuse box and start examining the fuses. It might not be a fuse labeled fuel pump, it might be something that seems completely unrelated, so check all the fuses with a strong light so you can see the element in there.
Pull any that looks even a little suspicious and either look closer at them, or use your meter set on "ohms" to see it its good. Ask if you need instructions for the setting.
DO NOT use the meter on ohms to test a fuse in the box. Remove it first. And turn the ohms function off as soon as you are through with it. Hooking the meter up to a connection with any voltage will blow the meter.
Easy to do if you set the meter down with it on ohms and pick it up later.
No torch? Go to the filler hole, take the cap off, and put your ear next to the hole while some one turns the key from off to run. Sometimes you cannot hear a really quiet pump from outside.
If all the fuses show good, you may be looking at a new pump. Sitting in old gas that long may have done it in.
Another quick and dirty idea, get something like a rubber hammer, slide under the car, and whang on the bottom of the fuel tank while someone cranks it. I have gotten many folks home from the woods with a bad fuel pump that way.
A bad bearing or a piece of dirt can cause the pump to not be able to start, but jarring it while its under power often lets it start. Once started, it will usually keep running until you shut it off.
But then will usually not start again.
Click to expand...

Have to admit, i'm a little afraid of propane. Can't i just use starter fluid?
 
rampage said:
If the cable ends were bad then more than likely the wire inside the cable is corroded also leading to increased resistance and future electrical problems. Might want to just buy new quality cables. Yes.

Here’s what I’d do. First is to check the fuel pump. Most will say to use the jumper wire for the relay under the hood, but to rule out any wiring/relay issues I run 12V to the unplugged pigtail at the gas tank. You could even use a 9V battery if you want, I’ve done it and it runs the pump just fine as long as it’s a fresh/strong battery. The grey wire is 12v to the fuel pump (purple wire is for the sending unit so ignore that). For ground scrape away the protective coating on the gas tank to get down to bare metal. The lip in the middle of the tank is best so you don’t need to worry about rust holes forming. So 12V to grey wire and ground to bare metal. Do not rely on the ground wire that’s there since it may be bad, that’s why I want you to use your own. Should hear the pump run. Once we know the results we can go from there.
Click to expand...

Is it ok to run a 10-14 ga wire all the way back there from the batt + terminal?

Also, and i don't know if trucks have this, but i was doing some reading in the service manual and on cars there is a fuel pump test connector (which i ASSume bypasses the relay?) behind the driver's side strut tower.
13GpSfQ.jpg

There are tests involving that connector and a test light outlined in the service manual which i'd like to try as well.
 
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Noek said:
1988 K5 blazer - original 350tbi

Man, I normally don't post but I couldn't pass this one up. I had a no start condition. At first I thought it was a fuel pump so I removed the line to the TBI and fuel came out like a water hose. Then I thought maybe it was the regulator in the throttle body even thought the throttle body was brand new, so I tested for spark at the injectors....no spark. Here is a list of the things I changed trying to get my truck to start, and I may be forgetting a few:

Throttle position sensor, temp sensor, distributor cap and rotor, coil pack, all new wiring and grounds, ignition control module, oil pressure sensor, ECM, fuel pump relay, eprom chips, throttle body, full re-wire. Still no spark at the injectors.

All of that work and looking online I have realized how crappy and fragile the TBI system is and when something goes wrong, it really goes wrong. I have read some instances, like mine, where nothing has fixed the vehicle and people just swap to a carb.

I know the TBI vs Carb argument is alive and well and I was always a big TBI proponent just because of the self tuning aspect and it seemed simpler. Now after realizing how many different components can affect a no spark condition and how difficult it is to properly troubleshoot it, I think its garbage. The wiring itself is completely insane and most shops in my area won't even touch the thing unless I am willing to shell out a lot of money just for trouble shooting.

I am finally done with this thing. I just purchased a turn key Ls3 with a 4L70E. I realized I really like this truck and I was fine with the 350TBI but am no longer willing to invest time and wasted money on the motor. So happy I made the decision and cannot wait until it is installed.

Good luck, I hope you have better luck than I did.
Click to expand...

All along i thought TBI was actually simpler than carb (at least on paper.....) And deep down, i thought/knew i would eventually switch to FI exclusively and i should try to push myself to learn FI. But i've never really had a problem with carb and distributor setups.

i think TBI does run great----when everything is 100% perfect. It does seem finicky is something is "off." At least with carbs/distributors i may not be able to get it to run smoothly, but it will run. So, i'm not totally convinced about fuel injection just yet. Maybe if you designed your own system using megasquirt or something?
 
I'd use the relay test wire (on a car it's probably a pin on the ALDL connector, trucks were only ones I know of that used a wire in the engine bay) just because it's easy. IF that test fails, then I'd go to the tank connector. Really wouldn't matter which way you go, at the tank proves the pump will or won't work immediately, at the relay/ALDL connector either tells you everything in the circuit after the relay works (if the pump runs), or that one of several problems could exist after the relay (if the pump won't run).

Edit: You don't need to run a wire with a meter. Disconnect the fuel pump connectors at both end, ground the end at the fuel tank side, and use your meter to check continuity to ground at the engine side of the connector. This will not show bad wiring, but it will prove that wire isn't broken.

BTW, no problem using that test lead if you like, interesting that a car had it. Must be TBI vs multiport!
 
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vandelay industries said:
Is it ok to run a 10-14 ga wire all the way back there from the batt + terminal?
Click to expand...

Yes. Doesn’t take much current to run the pump.

If you want to do the fuel pump jumper then (IIRC) it’s located on the center(?) of the firewall and it’s the loose red wire, just connect 12V to it.
 
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