Car won't start!!!!!

[Alfonso Gomez]

ad ad Friday night I took my wife to Hard Rock Cafe in the Vette (87 Coupe). While going about 40 mph the engine quit, so I shifted into neutral and started the engine with no problem. After dinner, the car started fine and we drove home (about 13 miles). On Saturday at noon, we went for lunch at my in-laws, about 2 miles away, the car started fine. After lunch I tried starting the car and the engine turned over but did not start. After about 15 tries, I called the tow truck and took it home. Abot six hours later, the car started on the first try:confused :confused and I shut it down and restarted it about six times with no problem. Then, on Sunday I tried starting it and it did not start. After trying about 15 times I gave up. This morniong the car would not start. I tried this afternoon and it started fine but quit after idling for about three minutes. Then it would not start again. The gas tank is full. The only thing done to it lately was disconnecting the ABS system but I don't think that has anything to do with it.
In this condition, I cannot drive it to the shop because it can quit any minute then I would have to tow it. Where can I start to check the problem? Ignition coil? Electrical problem? I checked this morning, before trying to start it and it had pressure in the fuel rails. Any help will be appreciated. It is an 87 Coupe, with auto trans. It only has KN filter, cut lid, Hypertech thermomaster chip and throttle body airfoil since about a year and a half.:eek

 

[vigman]

Does it not crank......

Or it cranks..but no fire?

Vig!

 

[vigman]

AH.. cranks.. but doesnt fire

You need to check the fuel delivery system.. starting with the fuel pressure, and working your way around.

Get a fuel pressure gauge.


Vig~

 

[Alfonso Gomez]

It cranks OK but starts when it feels like it. Sometimes, if you leave it alone for an hour or so and then try to start it, it gives like a very short start, like a burp, but does it only once and does not start. You keep trying and it won't start. Maybe tomorrow it starts, who knows. I checked the pressure at the fuel rail by taking off the cap in the valve where the pressure gauge is supposed to be connected and using a small pick pressed into that valve and gasoline spurted out under pressure. I have to get a fuel pressure gauge to test the pounds of pressure but the presence of fuel at the fuel rail gives me the indication that the fuel pump is working. Is this correct?

 

[drkjr]

Boy Al, your problem does sound a lot like mine! Someetimes, in the mornings, i will go to start it, and it'll crank over and almost start, but then nothing after that, just turning over but nothing even close to starting. i have to wait from 15 min. to a half hour, then it'll start, but give kind of a backfire, smelly fumes, but it'll be ok, for a while. Then while driving, it'll start to sputter, service engine soon light will come on, sometimes if i pump the pedal it'll stay running for a little while longer, but most of the time it stalls, but 85% of the time i can coast, throw it in N and restart it. Mechanic's tested the fuel pump, and system, says everything is ok, pressure is fine. He's putting in a new ECM tomorrow, i will keep you posted on the results!

 

[Alfonso Gomez]

Today I tried to start the car (87 Coupe) and it did not start. Then I noticed that when I turned the key to the 'ON' position, the "check engine" light did not go on. It is supposed to go on for a few seconds when you start the car. Then I noticed that in the digital cluster it reads in the 'miles per gallon' screen: 99. In the screen that tells you how far you can travel with the available fuel at the 'mpg' rate its reading over 500 miles. This is definitely out of whack. Can it be that the ECM is bad? I installed a rebuilt one about 2 years ago and then a Hypertech thermomaster chip about 18 months ago. Can that be it?

 

[Pappy]

could be ECM or TPS sensor or Mass air flow sensor, Just because you have fuel in the fuel rails doesn't mean you have proper pressure,you need a fuel pressure guage. Take a screw driver and lightly tap on the TPS and Mass sensor to see if that does anything. Do you know how to check trouble codes by jumping the A and B switch on the tester connector under the dash?This will give you some trouble codes logged in the ecm if any.

It's hard to pinpoint troubles like this with out the proper equipment. But just a few suggestions to look at.

 

[vigman]

Check & recheck

Alfonso

This sounds like 1 of two things
Bad ground

or

Lack of power/ good connection to ECM

Check my post on "Getting Grounded"
Inspect /clean/tighten as needed.

2a) You were having battery problems a while back.. correct?
I would re check those connections as well.

2b) Pull the ECM out ( battery off ) and clean the two connections going into there. Use a good quality electrical cleaner..and NOT WD-40 or carb cleaner.
If worse comes to worse just seat & reseat the connectors a few times.

2c) Did you look into the fuel pump relay ( connections & relay )?

2d) Next time it cranks.. but it doesn't fire.. get a can of quick start and spray it into the throttle body..if the car lights off then dies...it's fuel.

Electrical problems are the WORSE via remote control..

OH YEAH... DUH When the car is running fine the check engine light works properly.When the car WONT start.. the check engine light stops working..right.

When the check engine light DOESN'T work.. check if you have power to the ECM fuse ( 5 amp I believe) in the pass side fuse panel.

I helped another member with this via YAHOO IM.

It turned out to be a fusible link... I'll get a post BRB


Vig~

 

[vigman]

Read this post.. the WHOLE POST!

http://www.corvetteactioncenter.com/forums/showthread.php?s=&threadid=20614&highlight=Fusible+link


This might solve YOUR problem


Vig~

 

[Alfonso Gomez]

Today I put in a rebuilt ECM. Car did not start and had no pulse in the injector I put the test light in. Then jumped terminal G in the ALCL and only a slight click was heard. Then put a jumper cable from terminal D to terminal E in the fuel pump relay and the car started fine, Removed the test light and jumper cable and the engine kept running. Shut it down to reconnect the injector plug and restarted fine. Kept running at idle for 3-4 minutes then the engine quit. Restarted several times and it started fine. I kept the engine running at idle with occasional bursts to 4,000 rpms and the engine is still running since 40 minutes ago. No hesitation at all. Steady as a rock. Could it be a bad fuel pump relay? I noticed that when it started, the fuel level was down one fourth. Then when I restarted the second time, it went back to Full. Relay or sending unit?
Thanks all of you for you help.

 

[vigman]

Here's the Fuel system step by step (c-4)

http://www.corvetteactioncenter.com/forums/showthread.php?s=&threadid=7501&highlight=Fuel

More fun reading for YOU!

I think the ECM was NOT your problem.

Vig~

 

[vigman]

Do the following test

When the car doesn't start

See if PIN "C" on the oil sender ( orange wire ) is hot.

This should be 12 volts DIRECT to the battery.


Mike