alright after I swapped the lo3 to a l98 355 for some reason the starter is not getting a full 12 volts, check engine light stays on at all times, no codes, and only cranks at about 1/4 speed. After cranking for about half a second all power to starter shuts down. Checked all wiring on the 91 z28 harnes and everything looks good. I used a 91 z computer and oh yeah I disconnected my alarm and after checking all wiring everything is like it should be but I only get 4.6 volts to starter. Anyone know what I might be missing, below is a list of the crap I have done.....(three different mechanics/electrical genius's have looked at the car and no one knows what is wrong...a $100 money order will be sent to the first person who can help me how fix my problems) FYI I started the car 2 weeks ago and it ran fine for 45 minutes but now it won't start and nothing has changed........

1991 camaro rs
originally 305 tbi
now tpi 350 bored .30 over
comp cam
91 z28 harness and computer
disconnected audiovox alarm
145 speedo
and everything else in signature

 

ECM Chip. Check and be sure the ECM Chip is good. Try one from another L98 car first before sinking your money into one.
If everything else is right, as you said, are you still using the TBI computer chip?
I have the feeling it may be the right ECM but the wrong chip in it.
Could be a bad ECM as well.
Something cooked.

 

nope chip and computer is good, I tested both with another 91 z and everything worked like it was supposed to. the prom is for a l98 checked that out first. I thought about a cooked up wire but I pulled off harness and all wires are still intact.

 

VATS.
ECM and VATS
I'm sticking with the ECM and the VATS. You're going to need that 100 bucks for other things.

 

still somewhat cranks so vats is not an issue. temp. bypassed vats but no change in slow crank. I think it has something to do with inside the car and alarm delete but I didn't install the alarm so I don't know what I am missing.

 

My money is on the starter solenoid. Mine did the exact same thing, only it only did it while hot. But the voltage stuff is exactly the same. I would crank for a second and all voltage to the starter would competely disappear for no reason I could find. Wait like 5 minutes and it was magically back. Try again and the same would happen (until it had been long enough that it cooled down enough) Only difference is I did have a full 12 volts going to it to start with, however I'm still very suspicious of the way you're describing the voltage going to zero... It just shorted out something internally or something...

I ended up just installing a Mr Gasket remote soleniod kit ($50ish) since my problem was heat related (it only did all this when it was warm). Problem solved, you don't even actually take the old solenoid off the starter so install is pretty easy. I would take at look at the replacing the soleniod if I were you, either a stock replacement or the remote kit if you've got headers since you'll want it sooner or lately most likely...

(I have no VATS on a 87, so not sure just how it acts. Sounds like you've taken care of it though...)

 

Not getting full voltage to the soleniod sounds like a classic case of a bad battery cable. Check the large cable to the starter. It should have a constant 12 volts. Also check the battery voltage. If those check out fine, take off the starter and take it to a parts store and have the test it. They can measure the current draw for the starter and check it against the acceptable range for your application.

 

allright kids class has begun...


thanks for the replies but I bench tested the starter and it cranks up like it is supposed to when 12 volts is applied and a screw driver is applied to both terminals. Starter is a few weeks old, battery cable and battery is 4 days old. battery is at 12v according to meter. I think this car hates my a$$, but I will defeat it someday......

 

Wouldn't a screw driver being applied over the terminals in effect be bypassing the internal **** of the solenoid? Because the remote mount kit basically does that with a plate over the terminals of the stock soleniod in place (and mine was most definitely bad). The other solenoid does the work... Like I said, kinda odd that voltage dropping to zero thing in both cases. Does the voltage pop back up immediately after you quit trying to crank it, or is there a delay before voltage returns? Just wondering, would be one more similarity.

Was it a cheapy solenoid from Pepboys or something by chance? I never trust anything I buy at the auto store chains anymore, lol...

 

try touching a voltmeater from the end of the battery cable that attaches to the starter to an engine ground, also cgeck that the grounding strap on the back of the engine is there and is a good ground, 'cause that is where the engine gets most of it's power from and that will cause starting problems

 

If you used a screwdriver to connect the terminals, then you haven't ruled out a bad solenoid.

 

I used a screw driver to test the starter by grounding the two starter post together to see if it would come on and it did just as if the key was turned on. same principal as hot wiring a car to get it started without a key!!!! the end of the battery cable gets 12. However the yellow wire under the steering column that hooks up to one of the fusible links also only gets 4.6 volts also.

 

Yeah but that bypasses the Soleniod, which is what I suspect of being the problem...

Oh well, If you don't find another problem just keep the soleniod idea in the back of your mind...

 

if the solinoid is suspect how would using the screw driver method bypass the solinoid? no one thinks the check engine light staying on when started and when not started (when everything worked) and slow cranking has anything to do with the difference between 91 rs in car wiring vs 91 z28 engine wiring? I have heard from some people it is plug and play and from other people you have to do this this and that. I am definatley at a loss and don't know where else to go. So I have posted this same topic on a few boards to get a broad range of advise. All of the replies are appreciated.

 

should be 12 at solnoid - bad fuse link or bad ignition switch (hope it's the fuse link 'cause the switch is a PAIN to change)

 

Did you paint the engine before installing it? If so, you may need to scrape off all the paint to ensure good grounds...on the back of the heads for the ecm grounds, then between alt bracket and block for the battery ground.

Unless the timing is way advanced...I'm betting on bad grounding.....assuming your starter and solenoid are good.

 

BTW, if I am the winner, send the money to Dirk.

 

Okay.
On 1990 and later models.
You have:
A fuseable link from the ignition switch that goes to a starter enable relay... (linked to VATS).
If pass, it will allow the voltage to make a complete circuit.
If fail, it won't.

Chapter 10 / Page 10-17
Electrical wiring diagrams Haynes Automotive Repair Manual.

 

Check the Park/Neutral safety switch on the shifter. Could be a loose contact there. If I got the right answer, I'd like some copper header gaskets and an LT1 intake manifold Gasket set.

 

.

 

Will it start if you jump it from another car with the gound cable going to the engine ( not the battery post)? If you can jumper the solenoid with a screwdriver and the starter will crank the engine, then the contacts in the solenoid cap are probably bad. My starter
needed the screwdriver several times this winter and I replaced the starter and then problem was gone. I have also seen defective positive cables that looked like new. Use one of your
jumper cables to replace the suspect cable (leave the old one on).
If it will start with the jumper cable, then the positive (or ground ) cable or its connection is defective.

 

I am not saying I am right or wrong. I just looked into it, to make sure that I'm following it in the right direction.

 

What you effectively did was bypass the solenoid. Try doing it again with the ignition on and seeing if it starts. If so, your starter solenoid is bad. I believe the solenoid is more expensive than the starter itself, so unless you have some means of only replacing it, you may as well replace the entire starter.

 

.

 

Hmmm.

 

Here is the diagram:

 

My theory is:
The BLK wire attaches to the positive link on the battery to the starter. Assuming it is not the solenoid, the loop continues.
At the ignition the switch goes into a starter enable relay hooked into the VATS. (pass key decoder module) which goes to the gear selector/clutch start switch.
That completes the circuit.
The full voltage is only allowed when VATS allows the gate to connect.
If not, only VATS has voltage.
VATS has to read the key!
It needs power. It gets power when you turn the ignition key!
It will not allow 12V to pass if it fails!

 

try and start the car without the prom installed, if it turns over and starts (car will run without a prom, mine did) could be like Snowdog says, Vats module.

 

I wrestled with a low starter voltage problem one time on my old 84Z. Just could not get it to turn over normally (without bypassing like that). Worked on it 'til the sun went down. Then in the darkness, I noticed the glowing ground strap. Added another ground strap, moved the negative battery cable to a bolt on the motor (it was on the frame), "bam" the car started right up.

 

I had the same problem after I relocated my battery to the trunk, the main ground wire was a small braided line near the firewall, got hot and melted a vacuum line.

 

Many I had this problem before also. That stupid braided wire that goes from firewall to the intake manifold gave me problems for a couple of days. Replaced it with a 4ga. wire, no problems since.

I missed the answer by a few hours.

 

Even if the wire from the (-) battery post to the engine block looks like its a good connection, I would still disconnect it and clean it with a wire brush to get rid of any corrosion. I had the same problem with my old car and the wire looked fine... until you pull it off and actually look at it . Good luck.

 

I'm with some of the other guys. I say ground strap. I had a similar problem once when I put my new engine in.

 

All these people are saying ground strap but I don't get it... the actual strap can't flow the current of the starter, isn't it the 4 gauge (thick) wire coming straight from the battery ground post to the block that flows the starter's current? The dinky little wire going from the battery to the chassis, and then from the chassis to the block isn't a good path at all for the current of the starter to flow through. It's the thick wire from the battery to the block, no?

 

allright here is my plan: I am first going to pull the wiring harness out and recheck all wires in the looms. If ok I will clean up all ground straps reinstall and try to crank. I remember when I got the car started my braded ground strap on the fire wall seemed warm so I will replace that as well. should this be grounded on the back of the head with the others or on the manifold like someone else said?

Hopefully by Sunday I can declare a winner but at this point I can't start working on it till tomorrow morning (day off from work). I think JZA is on too something but should have some updates for you guys tomorrow.

 

it's your battery!.... the batterys of today just die... not like the old days where they would warn ya for a few weeks before giving up. this happened to my wife... and when it dies you can't even jump start the car.. ya just have to put a new one in.... try it!

 

False. Battery technology has been the same for many years.

 

I had a similar problem. Car would crank real slow and then pick up and start. Then it started to crank real slow and die. Battery said 12V, but when load tested(I had to convince the guy to do it, he said it was fine) it came up bad. I know you have a new battery, but it might be worth takeing back and having them load test it. Good luck

 

Yeah, the braided ground strap I'm talking about goes from the dist. clamp bolt to the firewall. I've also seen them bolted to the head. Over time these wires get real brittle and just arent worth a crap, they get really warm and start melting anything they touch. I just replaced mine with a better looking and thicker wire, two birds one stone kind of thing. Mine ended up breaking in half on me, rendered it unable to start. It wouldnt turn over or click, nothing.

Hope that helps.

 

I had the same problem on my Gta when I went to put the new engine in it and I had some bad connections on the back on the heads. There is on ground that goes to the back of one of your heads that will cause the problem you are describing. If you check the grounds that were origionally on your heads (if you can find the little boogers) make shure you have a good connection IE: no paint on the heads in the threaded holes were the ground bolts go.

Other things it could possibally check (if you already haven't)

Don't check replace the battery cables.

Take the battery into your local autoparts store and have them check the battery for cca. You can still have full voltage and not enough cold cranking amps.

While you are there take the starter off and have them check the starter. But that won't completely eliminate the starter I have seen problems with starters that they will perform on a bench test and not on the car when under a load.

Other then that I know of no other things that will cause a starter to turn the engine slower then it should.

All that is concidering you arn't running high compression and using a stock style starter. That could definately cause a problem.

 

If you test the starter, have them test it with the old solinoid first, then have them test it with a new solinoid, make sure all the readings are the same, if the second one is better then more than likely the solinoid is bad.

I still think the braided ground strap is bad. If it is still there and looks good on visual inspection, that dosent mean it is good.

 

Just a theory.

 

K, me being the Person that always jumps the gun when I have a problem, and then finding out later that it was something so stupid as a Fuse or a bad ground, I say this.

Always start out with the simplest things,
Battery, what will it hurt and how hard is it to take the battery out?
Once you get it tested and you know positivly that its good, your battery is out of the question. Theres one Down.

Starter, I dont care you are obviously stating you have a problem with your starter, ripp the junk out, return it and get a whole new one. If the starter is Brand new, it shouldnt have any problems turning over a High Compression engine, but you never know, now would be the good time to just get a MiniStarter, so you have eliminated the problem of it not being able to turn it over, because of compression. 2 down

Grounds, Go back take off all the Grounds and clean the surface with a wire brush, if you did it once do it again, so you know you are positive that they are all good, clean the threads of the bolts with a wirebrush too. You should have 1 on each Head and then your main ground. 3 down

Fusable links, I have had these go out, but I would receive no power to the Starter, but I would have power to the accessorys. Easy test to know when there bad, they can stretch like Rubber.

There is no point in ripping out your harness in checking around it.Yet!

I have learned 2 things, one that my dad told me, that I never listened too, "If your gonna do it Half assed, dont do it at all" and "Theres no cheap way of getting a expensive needed part"

Buy yourself the ministarter, you are goin to find that if you have high compression, it is going to get hot and it wont crank over. I would run into this all the time, when I would drive it to the Track, which is about 20 miles away, I would get there, turn my car off, and then try to start it and nothing The only thing that could jump it was a Big *** Tow Truck, no other car would work, it needed that much power

 

If VATS was the problem, turning the key would give you nothing. It wouldnt crank slowly then die. It wouldnt do anything. You would have power when you put the key in, then turning the key would kill it all. Thats what happens when VATS goes. At least thats what Ive seen on the 10 or so that Ive fixed.

 

/

 

I wonder what the outcome will be...

 

when I did my swap and started it for the first time it started right up, idled for about 10 seconds and died cause of tuning problems. But anyway, when I tried to start it a second time, it would just crank about a 1/4 rev and stop. Turned about that the timing was set away too advanced for about 10.5 compression, and I guess that the spark is trying to push the piston down, thus working against the starter. I'm pretty sure that's why you can get some ingnition boxes with a start retard mode. I'm not saying that is what I had to get, I just had to turn my dist. cap way back.

 

The outcome is no good. Friday I pulled wire harness, checked all grounds( by checking I mean cleaning up even more paint regrounding to different locations, everything else you can do or thank of), traded in new starter for a even newer one, charged up battery and still same problem. When harness was out I took all looms off to check for pinched,broke or burned wires but nothing wrong. I have determined it is inside the car. I am back to thinking it has something to do with alarm disconnect. Tomorrow I have to fix up the girls car but after I am done with her it is back to mine. I am almost ready to blow it up!!!! For a swap that is so easy according to some this is really a lot of to fight with. From everything I have read, seen, done, and belived this is a pull the old one, drop new, plug and play, but the car g**'s must be real pissed off at me, since I am moving into a month of playing with this $hit

 

I sure hope you figure it out! Good luck!
Edit:
I am curious, did you fix that 4.6v anamoly?

 

Can you explain to us how you have the alarm hooked up, and how you think disconnecting it may be causing this problem? If you're talking about a starter kill relay it will be either full power to starter or none. As long as you pull the fuse to the main power wire of the alarm it should render the entire alarm system useless, thus not a source of your problem. If your setup is different, please explain it.