What the hell is going on!!!!!!

[British Bob]

Hi,

Given that my car is a manual shift , would i have that purple safety wire?

bb

 

[British Bob]

Right , its well past my bed time here in england, gotta get up earley . will be taking my car to a garage at some point tomorrow to get the negative earth looked at . will be checking this thread in the morning so if you guys and girls got any advice it realy would be greatfully recieved.


Thanks in advance

British Bob.

 

[89vert]

I'm thinking battery. Even though it is new it may require a good full charge with a battery charger. I had to put a battery in my 89 in the fall of 03 just before storing it for the winter. I had problems with the battery holding a charge for the winter. I put the battery on a trickle charger for 24hrs and have not had a problem since.

 

[Black Bart]

Do you have headers on the car. You stated that it started cold but would not start hot that sounds like heat soak in the starter. Pushing it and it starts easy that tells me the ignition is good. Summit sells a heat blanket for starters I have one on my car to prevent the problem that you are experiencing.
A lot of vettes suffer from this problem after installing headers and some even do it with the stock manifolds

 

[tyrel]

Hmm, on C4s and most cars in general, it's best to take a systematic approach. I've always found that it's the simplest things that can cause poor starting or poor running. Check your serpentine belt, there is a little notch in the tensioner, the line should point somewhere inside that notch, if the belt is too slack it will cause all kinds of problems. Also check your vacuum lines, a simple vacuum leak will make even a new car run really poor. Check them carefully, even the ones that go underneath the plenum.

It is possible to buy a bad battery, I have done it twice now and there's nothing like that sinking feeling when you slowly realize the battery itself is bad. This is easily checked with a cheap digital voltmeter, which you should have anyway, shouldn't cost more than 10 Pounds. I have found that the battery and the alternator are the main culprits with poor starting problems, and it is possible to buy a bad alternator as well, this can also be checked with the digital voltmeter. The last simple thing I can think of to check would be the fuel system, you can buy a cheap fuel pressure tester and hook it to the shrader valve on the fuel rail, start up the car, and read the pressure. If you're not getting at least 35PSI, I would suspect the fuel pump, the fuel filter, or a clog in the fuel lines.

You really should have the service manual after this point, because the next round of inspection would include things like the IAC (idle air control) or the TPS (throttle position sensor). You should make sure the timing is set properly. Check the distributor cap and rotor, and all your spark plug wires. Is your car setting any codes? If it says "service engine soon" on the display panel, pull the codes and post them here, it will be a start.

If none of these efforts produce a good result, you may have a bad ECM. This happened to me once, years ago, on my 1990 Corvette, they replaced the ECM and the car ran as good as new. You'd never think those things go out, but apparently they can.

Don't hate the car too much, it's sick and wants to be better.

 

[Bob Yates]

Hey Bob... I'm A Bob too ! And since no one has told you where the ground or earth is, I'll tell you. I have an 86 and my ground cable was loose where it grounded to the engine. It is on the drivers side of the engine almost above the oil filter. It is better if you get it on a rack or lift. There is not much room to trun a wrench. I did it laying on the ground with a floor jack and it was hard to get at and I use to be a Chevrolet Mechanic. Also grounded there is the computer so it is an important spot and needs checking . In my 40 plus years in the automotive area I've seen alot of bad starters causing your problem. I don't know your rebuilder but if their like ours here they try to get as much out of the old parts as possible and they end up turning the armature to small and it cause the micka in the armature to flow when hot and short out.Vetts need a good strong starter with a good thick armature so the heat won't short it out..... Like you, I don't think it is your VATS system because you push it and it starts. The vats system total kills the starter so you could push it til kingdom comes and it shouldn't start . Of course the other guys answering you here are also pointing out other causes. They could be right too. So hanging in there and you'll find it. Take care and good luck.....Bob Yates

 

[British Bob]

Thank you all , so much for the advice am going to a garage now armed with all this.

Cheers again

British bob

 

[redc4corvette]

What was done before the problem started?
What mods have been done to the car(engine)?
Is the alt hot to the touch?
If it's a top mount cable on the battery is the pos top of the battery touching the cross bar above the battery?

 

[British Bob]

Hi,

No mods that i am aware of, the car has never started very well but I always put that down to the VATs system as If i waited it would start. since the new battery, leads and starter motor the engine has never not tried to start, there is always a noise from the starter motor but not enough turn to start the engine.

Have just checked the earthing and it all seems fine. put a jump lead from battery straight to the engine block and no difference..

The car is now with an auto electritian who is going to look into it and will be using my log in for advice.

Can u think of anything else?

The battery is not touching the cross beam.

BB

 

[British Bob]

Hi

Had the car on a ramp this morning and the earth strap is very tight to the engine block with no sign of wear!!!!

bb

 

[tomtom72]

Just an observation

Hi British Bob, I'm a new C4 owner myself, 12/04, and did you order a Helm manual for the car? They print the GM service manuals for GM. Helminc.com is the web address. I will not venture to offer any diagnosis due to my rookie status with C4's. I do know that I would not be without the Helm manuals, I ordered the set as soon as $ changed hands on the car! Tom

 

[British Bob]

Hi,

yeah, did have one but lost it, car ran fine for ages so didnt bother buying a new one. Wish I had!!!!!!

Thanks anyway.

BB

 

[British Bob]

New Angle

HI,

The bloke looking at my car has said that the battery is completley dead!!! which is strange as I drove 45 miles into work this morning.

the alternator is working fine,

What would cause such a battery drain?

any one please.

British bob

 

[tomtom72]

Battery gets drained how?

Bob, The car started right up & drove into the garage? The mechanic checked the battery with a votl-meter & or a load tester & found the battery discharged? The things that come to mind if the alternator is working okay.
1) Does battery have a shorted plate(s)?
2) Is there something using power at an excessive rate?
3) Is a switch activated load not shuting off thereby sucking up output?
4) Is there a short to ground using up power?
5) Is there a voltage regulator(s) to any black box failing?
6) Are all the system grounds good. I noticed in my '90's electrical section there are alot of grounds. I also noted the vast # of relays in the car's electric sys. I apologise for not being more specific. I don't have my shop manual with me & I'm not sure how much help a 90 ser. man. would be & I'm not a mechanic so I don't dare extrapolate! In the old days you pulled fuses one by one with a test light to check for a circuit that didn't shut off when it was supposed to. I don't think that works too well in cars w/black boxes. Sorry I can't offer more! Tom

 

[British Bob]

Thanks mate.

The guys at this garage sound very confident that they will find the drain. I realy hope that they do and that this is the problem. I have spent an absolute fortune on that car over the last few months. If it was any other car I would have sold it by now!! but I cant , love it too much.

Thanks for your help

If you or anybody else can think of anything else I would be greatfull to hear.

Some one mentioned a purple wire earlier (neutral saftey something) mine is a manual car , do I have one, another thread suggests that I have?

BB

 

[JimVette]

You need to disconnect the battery and when you reconnect listen for switches to activate. I have found power window switches on the up side only short out and drain the battery. Good luck!

 

[tomtom72]

Don't die laughing!

Bob, The last vette I had was 19 yrs ago & it was a 72! That car I thought was complicated untill I got my 90 ZR-1 this past Dec. I took one look at the electrical diagrams in the electrical section of the Helm manual set and cryed! I thought "what have I gotten myself into?!". And all I was looking for was the wiring for the radio! I will say this about the purple wire, remembering I'm a dummy at modern cars! I can start my 90 (6 spd) in neutral with no clutch, or it will start in gear with clutch in. I guess it will not start in gear with the clutch out because there must be a switch that is open if the clutch pedel is up. I know my C3 had a mechanical linkage to a switch to prevent starting in gear. I guess our electronic cars have to have the same thing or a switch at the clutch pedel. EEC maybe great but it isn't clairvoiant, there is got to be something to not let it start in gear?? Sorry again, man I gotta bone up on this stuff or find a mechanic I can trust! Tom:confused

 

[Heavy Duty]

Man, a new battery that is dead. Sounds like it could be a bad voltage regulator that is either not charging the battery or allowing the battery to discharge. GM alternators have the voltage regulator in the alternator. You may see a normal voltage output but that voltage is not making it to the battery to recharge it. New batteries will for a time regain their voltage just setting. That is the reason why the car will start after setting a while. Case in point. Have you ever tried starting a car and ran down the battery to the point that the starter just would turn the engine? Then if you waited a period of time the battery would seem as though it had recharged itself and would spin the engine at a decent rate? That is the battery reserves kicking in to replinish the voltage/amperage in the battery. After so many eipsodes of the above, battery cells will start to go bad as plates in the battery lose their reserve activity. Once these cells get damaged, the battery can no longer hold a full charge or any charge if all of the cells are damaged.

So, I would double check the alternator and make sure that it is making the correct voltage but also make sure the regulator is working.

Second, it does take a lot more amperage to spin a hot engine, or a very cold engine, than it does to start an cool engine on a normal day (45-90 degress). Also, if there is a problem with the starter motor as mentioned. It will take more amperage to spin the motor. You can get a bad anything when replacing a part.

Don't give up. It is most likely a simple item that is causing the problem. Drink a few pints and I am sure that it will be sorted out

Just my .02 worth and experiance.

H.D.

 

[British Bob]

Thanks.

Will stick with this, cause when its hot and sunny and the roof is down and you hear people shouting "Nice car mate" as you drive past them its all worth it.

However the last week or so, the people have been shouting "Need a push!!!" which doesnt do much for the ego.

BB

 

[Dakota kid]

Post some pictures so we can see.