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Discussion Starter · #1 ·
Hi guys, I hope this is the place to post this question. I have been working on a friends 89 camaro with a 350 tpi. The problem is, it starts but won't stay running. To get it started, you have to give it gas like it's a carb. The same goes for keeping it running. You have to stay on the gas. I was told it has always been like this but once it was warm it was just fine. However, now once it's warm it still wont stay running. I did notice while keeping my foot on the gas yesterday, the security light was staying on even with the engine running. Here is what I know of so far: 1. I have read this year should have the VATS system and I assume it is right since it has a security light that works and 2. the steering column was replaced and the key that is used now does not have the resistor. Does this sound like a VATS issue since it at least starts but doesn't stay running? The only reason I ask is since the security light stay on even after the engine starts. Any help would greatly appreciated. I am going to get back to working on it tomorrow and hope to have a good starting point.
 

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If the column was changed, he should have installed resistors in the VATS line and the computer would read that as the key being in the ignition.
Does he have the old key to check the resistance?
 

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i don't think its a problem with the VATS.
if it was, the motor would start and run for about 2 seconds and die, no amount of pumping the throttle would make a difference.
some one may have bypassed the key part of the system, or swapped out the chip in the ECM and bypassed the starter lockout if it used it.
check to see if it has any codes stored in the ECM.

the first thing i would do is check the fuel pressure, it needs to be around 42 PSI key on engine off, around 35 PSI with the motor running.
its not unusual for the system to not hold pressure and for it to bleed off pretty quick. you may need to find the fuel pump prime wire and power it up. IIRC, it should be near the fuel pump relay.
i've seen some of the TPI motors start and run with as little as 20~25 PSI, but they were hard to start and ran very poorly.
 

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Discussion Starter · #4 ·
There was a key laying around in his garage but I am not sure if it was the original. I have already checked the fuel pressure and key on engine off it was at about 43.5 and about 36 with the engine running. It holds pressure too. I have also ohm checked all injectors and the lowest was reading about 9 ohms of resistance. I will have to check to see if a resistor was installed. I doubt it because the person he had install the column didn't even install the ignition switch the right way. I know it doesn't really sound like a vats issue but any idea why the security light stays lit while the engine is on. Also, the only code I pulled was a code 34 but that was because the MAF signal wire was grounding. The other things that I checked were the tps, iac, and timing. The timing is dead on but the tps was shot and replacing it didn't help. The iac also had a lot of buildup on it but cleaning it and resetting it didn't help either.
 

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Discussion Starter · #5 ·
Ok I found some information on the security light staying on with the car running. The following is what i found.

When SECURITY light remains lit with ENGINE RUNNING
it signifies a VATS error:
-trouble in the VATS module
-low battery voltage
-bad alternator
-bad battery connection
-VATS system disabled
-Contacts dirty or corroded on key or module
-HIGH resistance in wire (wire is ALMOST broken)
-Defective resistor in key

I have no reason to believe it is a bad alternator or low battery voltage because the battery voltage gauge is showing a steady voltage of about 14 volts. As stated earlier, the key that is used now has no resistor so I figure the steering column that was put in was from a car without VATS. I am going to run a compression check on it later today and see if the engine at least looks to be in decent health. I will post back to let everyone know what I find. I hope to get to the bottom of this quick. There is already over 14 hours in this car and have not made much headway.
 

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VATS is a separate system from the ECM and has its own light.
if everything is working right, it sends a signal to the ECM which will fire the injectors. if there is a VATS problem, the ECM will disable the injectors and set code 46.
with the security light on and without code 46 stored in the ECM, it leads me to think the chip was swapped out with one from an older model car.
from 86 to 89 they used the same ECM. 89 was the first year for VATS. 89 did not have a cold start injector, but all the others did. a chip from an 87 or 88 would work, but it may be hard to start in cold temps.
im not certain if the chip from a 86 would work or not, but as far as i know it will.
if you can, open the cover on the ECM and get the code off the chip.
it will most likely be all letters and looks something like ARAP, APYS or ANZA.

bad injectors can cause all kinds of problems.
multec injectors are known to short out.
if you have it, list the ohm readings from all of the injectors.
 

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Discussion Starter · #7 ·
I do not have each of the ohm readings. However, I know there were two or three with 10 ohms, and 1 with 9 ohms. I will have to check and post back tomorrow. While I was over there tonight, I ran a compression check. The results are as follows:

#1 - 140psi
#2 - 135psi
#3 - 120psi
#4 - 135psi
#5 - 110psi
#6 - 131psi
#7 - 120psi
#8 - 130psi

The car also through two new codes tonight. I think I mentioned before it set a code 34 but it was because of a grounded MAF signal wire that has been taken care of. Tonight I believe the codes are related. One was a code 33 MAF gm/sec hi and code 45 rich condition. I am beginning to wonder if the MAF is bad because the wires were stripped and the owner hosed the engine down with the motor running. Naturally it killed the engine. Is there any way testing the MAF? Also, I will post the injector ohm's tomorrow and post the chip code as well. I appreciate the help.
 

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you say he got the motor wet with it running, have you pulled the distributor cap and checked for water in it?
does it have good fire from the ignition system?

the MAF could very well be bad.
unplug it and see what happens when you try to start it.

the compression is low for a L98. it would be down a little on power and may run a little rough, but it should still start and run.

i believe the ECM in this car is made just like the ECM in the 90~92 TPI camaros and only has 1 injector driver in it.
with all the injectors at 16 ohms, the ECM sees 2 ohms, at 13 volts that comes to 6.5 amps.
with 2 injectors at 10 ohms, one at 9 and the rest at 16, the ECM is seeing 1.6 ohms and 8.1 amps of current. if there are 3 at 10 ohms instead of 2, its pulling 8.6 amps.
even if it does have 2 injector drivers, they are still being overloaded.
he is going to need a set of injectors, soon.
when they are replaced, stay away from the stock injectors, there are better injectors that are available on-line for less than what a set would run from the parts house.
 

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Discussion Starter · #9 ·
I tried unplugging the MAF today and restarting it and it made no difference. I will definately post the injector ohm resistance for every injector tomorrow. Is there any particular brand of injectors that you would recommend? I have read that the bosch yellow tops are a good replacement injector. I also found a troubleshooting flowchart for a code 33. I am going to go over it tomorrow. As for water in the distributor, I did not see any. The only thing I saw is normal wear and tear. The other thing I forgot to mention is that the IAT (I think) is disconnected. I think it is the IAT because it is located in the the air duct right before the MAF. I have read that the IAT is in the throttle body if I recall correctly. So is it in the throttle body or the air duct after the two ducts combine into one? Either way, I am going to have to find the connector for that sensor in the air duct. I think it may have been cut by the previous owner. If I knew where it was routed from I might be able to find it.
 

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Discussion Starter · #10 ·
I just remembered something after reading another article. I forgot to have my helper hold the throttle open and when I first started I only had the coil unplugged, not the injectors so it was sparying fuel while testing the first two or three cylinders. So, I think the cylinders may have been washed down. :spank: So a combination of the fuel injecting and forgetting to hold the throttle open threw the measurements off. So in all do reality, I'm willing to bet the compression readings aren't as low as they appear. Again :spank:
 

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Check and clean your IAC in the throttle body. If its gunked up or not opening not enough air will be able to keep it running. Jumper pins AB on the aldl connector under the dash with a paper clip, they are the two beside each other on the upper right. Turn the key to on. You should be able to hear and feel with your finger the IAC vibrating as it extends. If you don't clean it or replace it. To clean it remove the throttle body and clean the passage way. You can clean the IAC its self by unscrewing it from the TB wrap a rag around the sensor and plug in the connector. Jumper the pins like before and turn the key to on. The IAC will fully extend itself after 30-45 sec and the pintle and spring will come out in the rag. Turn off key, unplug connector and clean. To put the pintle and spring back in screw in as far as it will go without shaving the plastic guide thingy. You will need to gently push the pintle back into the IAC making sure the guides line up with the pintle, don't bottom it out just enought to get by the guides.
 

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Don't pop the IAC apart! These can be cleaned without this! All you need to do is remove the IAC, and spary it off with a good throttle body cleaning spray. Do the same for the bore, as well. The IAC pintle is calibrated, and if you remove it you pretty much destroy the IAC. While you are at it, spray off the throttle blades, and clean the backside off as well. If it won"t idle at all, the minimum airflow gap on the throttle blades may be gunked shut when the throttle is closed.
 

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This sounds like a MAF issue. The fact that you need to stay on the throttle to keep it running would make it look like the MAF is not sensing enough air movement. Unfortunatly guessing can get expensive. Do you know anyone with or have access to a scan tool (not a code reader). If you can get a hold of one it would be interesting to see what the MAF flow is and what the TPS readings are.
It sounds like you have a fuel/air metering issue.
 

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Discussion Starter · #14 ·
I use my laptop as a scan tool. The tps voltage was right at .538 at idle and goes up to 4.3 volts at wot with no glitches. The old sensor was a different story. It wouldn't even get up to 2.6 volts at WOT. As for the MAF, I looked at it but this is the first car that I have gotten the chance to work on with a MAF and not a MAP sensor. How many gm/sec is normal at idle? I found a troubleshooting flowchart for the code 33 it set yesterday so I am going to check the sensor and all related wires here in just a bit.

As for the suggestions about cleaning the iac and throttle body, I have already removed taken the iac apart and cleaned it. I have also cleaned the throttle blades, both the front and the back.

Thankfully no parts have been thrown at it. I learned from my tbi conversion on my 76 c10 that it does nothing but drain my wallet. :D The only parts that have been replaced needed it and even then, haven't cost a penny because he has another 89 camaro ready to be scrapped that has working parts on it.
 

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Soul_Hunter said:
i don't think its a problem with the VATS.
if it was, the motor would start and run for about 2 seconds and die, no amount of pumping the throttle would make a difference.
some one may have bypassed the key part of the system, or swapped out the chip in the ECM and bypassed the starter lockout if it used it.
check to see if it has any codes stored in the ECM.

the first thing i would do is check the fuel pressure, it needs to be around 42 PSI key on engine off, around 35 PSI with the motor running.
its not unusual for the system to not hold pressure and for it to bleed off pretty quick. you may need to find the fuel pump prime wire and power it up. IIRC, it should be near the fuel pump relay.
i've seen some of the TPI motors start and run with as little as 20~25 PSI, but they were hard to start and ran very poorly.
C10, did you check the fuel pressure??

Also here is some info for future reference if you do not have injector pulse to find out where it is originating from;

Get a 12V test light & clip the alligator to the Positive side of the battery, so that whenever you touch the tip of the probe to ground, it lights up. Unplug the 4 wire connector at the distributor. With the ignition switch on (in the run position), touch the tip of your test light to the HEI-REF wire. Check wiring diagram for position and color (It is one of the wires in the 4 wire connector), and then listen carefully! If you hear nothing, and you have no open or short to ground in that wire all the way to the ECM, then the ECM is faulty and should be replaced. If you hear the fuel pump relay click on for about two seconds and then click off, but no other noises, you have a fault in the VATS. It would be either the VATS module itself, or the ignition key (the resistor pellet may be too worn out) or the key resistor sensing terminals in the lockset of the ignition switch (to worn to accurately read the resistor pellet in the key). If you hear the fuel pump relay and you hear the injectors click, then you have a faulty ignition module. This is an accurate test and does work. As Soulhunter stated this test will be inacurate if someone ran a jumper wire across the starter enable relay. If this is done the car will crank even with a problem. Like I said this is to diagnose a possible VATs problem. I posted this to let others know how to quickly narrow the problem down. Hope it helps.

Kurt
 

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Discussion Starter · #17 ·
Sorry I forgot to mention the parts car is an 89 but it is a 6 cylinder.

I have the injector ohms that I promised I would post.

#1 - 15.6 ohms
#2 - 10.1 ohms
#3 - 15.9 ohms
#4 - 11.9 ohms
#5 - 15.0 ohms
#6 - 14.1 ohms
#7 - 10.6 ohms
#8 - 13.4 ohms

Also soul hunter, I got the vin from the car today and it says the motor is a 305, not a 350. I decided to get the vin instead of taking the word of the owner since he only bought it because he was told it had a 350.

Kurt, i have checked the fuel pressure and it is right in spec.

I also followed the troublshooting flowchart for the code 33 and it is pointing to the MAF being bad. Kind of figured it would though. As for the IAC, I pulled it and the plastic guide is stripped. I have a spare IAC laying around. I will put it in and see if it makes a difference. Thanks again for all the help guys. I feel like we are getting much closer to the problem.
 

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its possible the stock motor has been swapped out, you would need the numbers off the block to know.
you can look them up here,
http://mortec.com/

the chip code ANY shows to be from a 86 305. if there is not a fourth letter, then the ECM does not have VATS
because a cold start valve was used in 86 but not in 89, the car could very well be had to start when cold.

with the ohm reads you gave, at 13 volts the ECM is seeing 8.1 amps, thats 1.6 amps more than if all the injectors were at 16 ohms.

you say he has a parts car, does it have the injectors?
if it does, you can check them and see if it has 5 that are closer to 16 ohms.
if the parts car has been sitting for very long, the injectors could be stuck, its very common with the multec injectors.
if they are stuck, they can be unstuck, but they have to be fired either by an injector tester or the ECM and lightly tapped on with a wrench.

from what i've heard the bosch type 3 are some good replacement injectors. they are what i plan to use when i replace mine.
there is a guy here on this site that sells injectors, but i don't remember his user name name. when i get a new set for my car, i'll either talk to him or i'll get them from Fuel Injector Connection.
 
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