hard start and will not idle
Thread Starter
Heel & Toe
Joined: Apr 2010
Posts: 16
Likes: 0
hard start and will not idle
I'm posting on here because the site I use thirdgen.org is really unhelpful. Knowing that the camaro tpi set up is the same as the corvettes tpi set up, my girlfriends father recommended that I try this site since he's big into corvettes to see if someone here might be able to help me with my issue. I have an 89 camaro with a tpi 305.
I've replaced/installed the following;
fuel injectors
spark plugs & wires
cap & rotor
pick up coil
a set of headers
timing chain
fuel filter
My problem is I can not get the car to start with out putting my foot on the gas and cranking the key. Once it does start, if I bring my foot off the gas pedal it just stumbles and dies. I've omhed my injectors, and they came out okay, which they're less than a month old so I would hope they are good. My fuel pressure is ~42psi when my pump primes, and then goes to about ~40psi. So I have ruled fuel out. I'm new to working on cars in general, and the tpi set up is a bit frustrating.
Any help would be appreciated. Thanks.
I've replaced/installed the following;
fuel injectors
spark plugs & wires
cap & rotor
pick up coil
a set of headers
timing chain
fuel filter
My problem is I can not get the car to start with out putting my foot on the gas and cranking the key. Once it does start, if I bring my foot off the gas pedal it just stumbles and dies. I've omhed my injectors, and they came out okay, which they're less than a month old so I would hope they are good. My fuel pressure is ~42psi when my pump primes, and then goes to about ~40psi. So I have ruled fuel out. I'm new to working on cars in general, and the tpi set up is a bit frustrating.
Any help would be appreciated. Thanks.
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
If it runs with your foot on the gas I wouldn't expect the distributor to be in backwards. I'd look at the idle air controller in the throttle body, clean the throttle body, and adjust the throttle position sensor if necessary. I'd also look for a vacuum leak.
Ron
Ron
Thread Starter
Heel & Toe
Joined: Apr 2010
Posts: 16
Likes: 0
Well, I went out and bought a new TPS and put it on. I know that I'm suppose to adjust the IAC while the car is in drive, and then adjust the throttle posistion sensor. I'm able to get the car to idle after I start it by pushing the gas pedal like it's in flood mode still, once it warms up and idles, I put my foot on the brake and go to put it in drive so I can adjust the IAC screw and it just dies once it goes into drive. I've already checked for vacuum leaks while I had it idling with the EST unplugged, so I'm thinking a vacuum leak is not my issue.
Pro
Joined: Oct 2009
Posts: 679
Likes: 0
From: vero beach florida
You do not have to adjust the IAC to set the base TPS setting.
All you need is a volt meter and 2 jumper wires.
Jump the 2 top wires from the TPS to the connector, turn the key to ON and do not start, then put volt meter on and adjust till volts read under .57 and no lower the .52. This is not exactly what the FSM says for your car, I think it says .54, but my son's 88 ran best at .56.
Sorry, forget how to adjust IAC's.
All you need is a volt meter and 2 jumper wires.
Jump the 2 top wires from the TPS to the connector, turn the key to ON and do not start, then put volt meter on and adjust till volts read under .57 and no lower the .52. This is not exactly what the FSM says for your car, I think it says .54, but my son's 88 ran best at .56.
Sorry, forget how to adjust IAC's.
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Burning Brakes
Joined: Mar 2003
Posts: 1,174
Likes: 6
From: NW MN
Top of page is a tech tips link. You should be able to find how to do what you have to do there. Here are the basics you need to do.
1. Double and triple check all the work you have done so far. Make sure every connection and wire is installed correctly.
2. Check for vac leaks when you get the car started.
3. Set your base timing, with the work you have done you will need to get this set correctly.
4. Set you base idle.
Good luck and hopefully all goes well. Report back on what you find out.
1. Double and triple check all the work you have done so far. Make sure every connection and wire is installed correctly.
2. Check for vac leaks when you get the car started.
3. Set your base timing, with the work you have done you will need to get this set correctly.
4. Set you base idle.
Good luck and hopefully all goes well. Report back on what you find out.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
There is nothing to change the Base Idle over the life of the car except for one turning the screw so unless you did that and it then had the problem, there's nothing wrong with it.
The Coolant Temp Signal determines idle pulse width so find out what that is. You'll need a scanner or you can buy another one and plug it into the harness with it cold and then start it. If it works, R & R the old one; otherwise, see what the Sensor inputs are cold and post that info.
The Coolant Temp Signal determines idle pulse width so find out what that is. You'll need a scanner or you can buy another one and plug it into the harness with it cold and then start it. If it works, R & R the old one; otherwise, see what the Sensor inputs are cold and post that info.
Thread Starter
Heel & Toe
Joined: Apr 2010
Posts: 16
Likes: 0
Well now it's gotten to the point where the car is not starting. I don't know how it is for corvettes with the tpi, but with a camaro I can use a paperclip to short out the ALDL and my CEL flashes codes. I pulled a code 15, which is coolant tempature sensor failure, short, or ECM not working properly. Would that cause a no start issue also?
I have done #1, #2, #3 100 times. Just can't seem to get #4 done since the car wouldn't idle in drive. And now it's not starting. Will be getting a new coolant temp sensor tonight, or tomorow, so I'll will post if anything changes, and then go from there.
Top of page is a tech tips link. You should be able to find how to do what you have to do there. Here are the basics you need to do.
1. Double and triple check all the work you have done so far. Make sure every connection and wire is installed correctly.
2. Check for vac leaks when you get the car started.
3. Set your base timing, with the work you have done you will need to get this set correctly.
4. Set you base idle.
Good luck and hopefully all goes well. Report back on what you find out.
1. Double and triple check all the work you have done so far. Make sure every connection and wire is installed correctly.
2. Check for vac leaks when you get the car started.
3. Set your base timing, with the work you have done you will need to get this set correctly.
4. Set you base idle.
Good luck and hopefully all goes well. Report back on what you find out.
Last edited by puddingmmmmmmmm; Apr 14, 2010 at 04:22 PM.
Team Owner
Joined: Jan 2003
Posts: 20,322
Likes: 248
From: Summerland B.C. Canada
Well, I went out and bought a new TPS and put it on. I know that I'm suppose to adjust the IAC while the car is in drive, and then adjust the throttle posistion sensor. I'm able to get the car to idle after I start it by pushing the gas pedal like it's in flood mode still, once it warms up and idles, I put my foot on the brake and go to put it in drive so I can adjust the IAC screw and it just dies once it goes into drive. I've already checked for vacuum leaks while I had it idling with the EST unplugged, so I'm thinking a vacuum leak is not my issue.
What your adjusting is the minimum idle screw. Any turning of the minimum idle screw, will also move the TPS idle voltage, so that has to be re-checked for .54v (+/- .075v) at idle.
Read this for setting min idle and TPS. http://www.lbfun.com/warehouse/tech_...ch%20Paper.pdf
As for setting the IAC, there is no setting. The ECM will reset IAC, the next time the car is started.
Code 15 will make it run like ****, the ECM thinks it's on the north pole and will add crazy amounts of fuel, that's probably why putting it into flood mode, helps you get it started.
Fix the code 15 and then start over on the TPS and minimum idle.
http://members.shaw.ca/corvette86/Code%2015.pdf
Thread Starter
Heel & Toe
Joined: Apr 2010
Posts: 16
Likes: 0
I understand that, but would the coolant tempature sensor also cause it to not start
Have not had a chance with starting my new job to pick one up and throw it in, so hopefully Sunday when I am off I'll get one.
Have not had a chance with starting my new job to pick one up and throw it in, so hopefully Sunday when I am off I'll get one.
Team Owner
Joined: Jan 2003
Posts: 20,322
Likes: 248
From: Summerland B.C. Canada
I had a code 15 and it still would start, just run like crap. I wouldn't bother picking up a new coolant sensor until you have diagnosed the circuit. It could just be a wiring issue, following the link I gave you for code 15, will guide you through triggering a code 14, so you can rule out the wiring.
http://members.shaw.ca/corvette86/Code%2015.pdf
http://members.shaw.ca/corvette86/Code%2015.pdf
Melting Slicks
Joined: Jul 1999
Posts: 3,214
Likes: 101
From: Decatur, Alabama
And you replaced the injector with EXACTLY what kind and numbers...new or used? A bad MAF, weak fuel pressure, a coolant temp sensor off, a vacuum leak, cracked exhaust manifold are just a few things besides what you say youve replaced that may cause this. TPS, IAC, Timing, injectors are the main culprits assuming your positive plug wires are on correctly.
Thread Starter
Heel & Toe
Joined: Apr 2010
Posts: 16
Likes: 0
Replaced the injectors with new injectors from southbay.org 19lbs ford injectors. I do not have exhaust manifolds anymore since I put headers on. Tested my fuel pressure a bunch of times and that came out ok. Plug wires are ok, checked a million times. Timing, I'm going to take a look at that again, but I've also checked, and made sure it was set to 6*. I tested for vacuum leaks when I had it running, and couldn't find anything. Replaced my tps, and coolant temp sensor, still won't start now. Gonna double check using the chart agent86 posted, but I'm pretty sure it's not my wiring.
Thread Starter
Heel & Toe
Joined: Apr 2010
Posts: 16
Likes: 0
Slapped the new coolant sensor in today. My timing was way too advanced, but my girlfriends father helped me get it started with the EST wire unplugged. Got it timed properly, and now it's running pretty good. Turns on as soon as I hop in it now and turn the key.
Thanks everyone for your help!
Thanks everyone for your help!
