Random No Starts - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 26 (permalink) Old Aug 11th, 12, 06:54 AM Thread Starter
 
Join Date: Mar 2006
Posts: 20
Angry Random No Starts

I have a 91 Z28, 5.0/5-speed, purchased last fall. As far as I can tell, the only modification significant to starting/running is a MSD ignition module.
Until now, the car has started and ran great, except that 6 months ago I installed a new fuel regulator diaphragm (the old one actually had a hole in it!) and it ran perfectly again after that.
1 month ago all of a sudden it wouldn't start one afternoon at work . Long story short, I've found that it will start 7-10 times in a row, and then for no apparent reason it won't start. I've installed a fuel pressure gauge and have verified that pressure is good (42 to prior to starting even if it fails to start, 35 at idle when it starts, pressure rises with accelerator pressure).
I've been blaming it on bad fuel, and attempted this week to run the fuel out of it. The cars runs perfectly though once started, but on this latest attempt to use up the fuel I found that after some time, it would no longer idle. It ran great as long as the rpm's stayed up above 1500 or so, but if I let it idle it would immediately die.
I also found that while being towed it would start immediately when I let out the clutch in 3rd/4th gear. In fact I was able to get it back home under its own power as long as I kept the rpm up. (that was some tricky clutch/brake/accelerator action) Once in the driveway it had to be pushed into the garage because it would not start again.
Thoughts on this problem please!
eroclese is offline  
Sponsored Links
Advertisement
 
post #2 of 26 (permalink) Old Aug 11th, 12, 07:47 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,709
Garage
Re: Random No Starts

I would check all vacuum hoses for cracks and any hose in question, replace it.
The biggest vacuum leak would the EGR valve in the bottom of the manifold. If a bit of carbon/soot is stuck in the needle & seat, vacuum leak. One can test by reaching underneath the diaphram cap and raise the needle through a hole. If engine dies, good EGR valve. If in doubt, replace it and the temperature sensor attached to it.
I would cjhange the fuel filter and add fresh fuel.
I suggest to buy a Haynes manual and read how to extract diagnostic codes stored. Plus the book is worth the expense.
Last swap out would be the module with either an AC/Delco or Standard Parts replacement and don't forget to smear on the heatsink compound. Don't use dielectric grease as it will prevent the transfer of heat from module to dist body.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #3 of 26 (permalink) Old Aug 11th, 12, 03:12 PM
Senior Tech
Steps
 
Join Date: Dec 2005
Location: New Zealand
Posts: 13,316
Re: Random No Starts

We have had a strring of cars thru the workshop lately..all the same sort of thing, some also hesitation and loss of power...
Every one has been the bloody egr.. either as Evereet says above , or has been left longer and he EGR desposits have built up in the inlet manifilds choking the air flow.
A quick check to sort between electrical or fuel....if it starts on 'engine start' (ether) its a fuel and visa versa.
Yes check vaccuum leaks, and also check PVC valve is clean and closes.

My Spelling is not incorrect...it is creative

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Steptoe is offline  
 
post #4 of 26 (permalink) Old Aug 11th, 12, 04:21 PM
Senior Tech
Chuck
 
Join Date: Apr 2007
Location: Austin, TX
Posts: 926
Re: Random No Starts

Find out what is lacking when it won't start, spark or fuel. Should help narrow it down and better than just throwing parts at it, hoping for a fix. Not idleing sounds like a bad IAC valve, if it has one.
Chuck is offline  
post #5 of 26 (permalink) Old Aug 11th, 12, 05:06 PM
Gold Lifetime Member
Kevin
 
SixtyAte's Avatar
 
Join Date: May 2005
Location: S. Eastern Massachusetts
Posts: 5,536
Re: Random No Starts

Also check the VATS system. You should have a chip in the key that can cause problems if broken or dirty. Clean with alcohol on a q-tip. Also stick the q-tip into the key slot on the ignition and clean the contacts. The VATS system will disable fuel and spark. If you have a spare key, try that. If not go to a local Locksmith and have then find the Ohms of the chip and make you a new key.

Kev
SixtyAte is offline  
post #6 of 26 (permalink) Old Aug 11th, 12, 05:56 PM
Gold Lifetime Member
Lynn
 
Join Date: Dec 2004
Location: Oklahoma City
Posts: 3,104
Re: Random No Starts

Going to go out on a limb here. Before I do, here is my disclaimer.

I have never worked on a GM fuel injected car, other than the time I offered to crawl under a Blazer and hit the gas tank to see if the car would start for a poor guy stranded 200 miles from home (it did and knowing that I just jolted his in tank pump on, I told him not to turn it off until he was at home or at a repair shop). Now, I know your pump isn't the problem. I only offer that as my disclaimer.

If your car won't run below about 1500 rpm at certain times, and has trouble starting intermittently, but will still run above 1500, then I would suspect the throttle position sensor (TPS).

Lynn
bilodeaulynn is offline  
post #7 of 26 (permalink) Old Aug 11th, 12, 09:11 PM Thread Starter
 
Join Date: Mar 2006
Posts: 20
Re: Random No Starts

thanks for all the great ideas. I will check into them more this week. I find myself leaning toward the key problem actually. The steering column is not in perfect shape because someone tried to steal it once per the previous owner. It is quite possible that the contacts in the ignition switch itself are losing contact!
I will be checking the other ideas as well though.
eroclese is offline  
post #8 of 26 (permalink) Old Aug 11th, 12, 09:18 PM
Senior Tech
Kev
 
Join Date: Dec 2007
Location: North Texas
Posts: 621
Re: Random No Starts

Dumb, simple test (and already suggested) shoot some B12 in the intake while cranking.
Nobody likes simple...
67sc is offline  
post #9 of 26 (permalink) Old Aug 12th, 12, 05:33 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,709
Garage
Re: Random No Starts

If you look into the key chip, unplug the steering column connector, insert key into tumbler, and measure the key resistance value at the two thin gauge white wires.
No resistance or intermittent, no VATS satisfaction, no start, or rather, no starter crank over. Tumbler will need replacing, steering wheel will need removal, and proof of ownership and original key at any GM dealership will get you a new tumbler with keys.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #10 of 26 (permalink) Old Aug 12th, 12, 06:19 AM
Gold Lifetime Member
Kevin
 
SixtyAte's Avatar
 
Join Date: May 2005
Location: S. Eastern Massachusetts
Posts: 5,536
Re: Random No Starts

Quote:
Originally Posted by Everett#2390 View Post
If you look into the key chip, unplug the steering column connector, insert key into tumbler, and measure the key resistance value at the two thin gauge white wires.
No resistance or intermittent, no VATS satisfaction, no start, or rather, no starter crank over. Tumbler will need replacing, steering wheel will need removal, and proof of ownership and original key at any GM dealership will get you a new tumbler with keys.
Everett,
Any VATS key with the ( 1-15 Ohms ) chip can be bought at a local Locksmith and cut for the car. A module can also be purchased there. A pass-key system is the weak link in anti-theft. Just think..they used it first in the 1985 Corvette.

Kev
SixtyAte is offline  
post #11 of 26 (permalink) Old Oct 15th, 12, 03:11 PM Thread Starter
 
Join Date: Mar 2006
Posts: 20
Re: Random No Starts

Hello all,
Although it seems that I am ignoring any update on this issue, the fact is that there hasn't been much update until now.
I've found a suspicious pile of rust under my distributor cap!
Long story short, I need to know how to remove this retainer. I am pretty sure that this is the original distributor...not only because of the rust but the previous owner was meticulous about saving every little receipt and there was nothing about a distributor in the pile...but this does not look anything like the poorly drawn illustration in my Camaro Service Manual.
Suggestions please?!
I've never tried to post a picture, so if for some reason it is not visible please advise me of that.
Attached Thumbnails
Click image for larger version

Name:	2012-10-15_16-45-11_237.jpg
Views:	66
Size:	71.0 KB
ID:	30372  
eroclese is offline  
post #12 of 26 (permalink) Old Oct 15th, 12, 03:15 PM Thread Starter
 
Join Date: Mar 2006
Posts: 20
Re: Random No Starts

Seems that the picture was successful, so here are some more that I ran into...well, I guess just one more.
Attached Thumbnails
Click image for larger version

Name:	2012-10-11_19-45-50_375.jpg
Views:	73
Size:	40.7 KB
ID:	30373  
eroclese is offline  
post #13 of 26 (permalink) Old Oct 15th, 12, 05:34 PM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,709
Garage
Re: Random No Starts

Good troubleshooting.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #14 of 26 (permalink) Old Oct 15th, 12, 06:56 PM Thread Starter
 
Join Date: Mar 2006
Posts: 20
Re: Random No Starts

Thanks, but what is the secret to removing that? Can it be done without destroying the retainer?
Can that assembly be lifted as a whole unit off that shaft? I can get under the whole thing with a small gear puller probably but am I going to be sorry I did that because something under there that I still need will be destroyed?
eroclese is offline  
post #15 of 26 (permalink) Old Oct 15th, 12, 07:07 PM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,709
Garage
Re: Random No Starts

There might be a retaining ring to remove with a scribe, then lift out the pickup coil.
Check the pictures at RockAuto for ign pickup coil.
You could always buy the next higher assembly as a last resort.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome