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'85 GT hard to start when warm by NetCam
Started on: 08-19-2012 08:51 AM
Replies: 11 (891 views)
Last post by: Kevin87FieroGT on 08-19-2014 08:55 PM
NetCam
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Report this Post08-19-2012 08:51 AM Click Here to See the Profile for NetCamClick Here to visit NetCam's HomePageSend a Private Message to NetCamEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have a completely stock 2.8. If I start it from cold it fires up perfectly. If i run it for a while and it gets a bit hot, it will crank quite a bit and quite often it will require a bit of gas before it will start, and then i can smell gas after it fires up. I have put new AC Delco plugs in, a new coil, ICM, and have set the timing to 10 dbtdc. Any ideas what to look at next?

Edit to fix 'stock 2.6'

[This message has been edited by NetCam (edited 08-19-2012).]

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jetman
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Report this Post08-19-2012 09:16 AM Click Here to See the Profile for jetmanClick Here to visit jetman's HomePageClick Here to Email jetmanSend a Private Message to jetmanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Any codes? How's the air filter, gas filter and O2 sensor? Original Cat clogged? How has the gas mileage been lately? Has the probem just developed or has it been progressing over time?

[This message has been edited by jetman (edited 08-19-2012).]

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Dodgerunner
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Report this Post08-19-2012 09:57 AM Click Here to See the Profile for DodgerunnerClick Here to visit Dodgerunner's HomePageClick Here to Email DodgerunnerSend a Private Message to DodgerunnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
FYI that's stock 2.8. (typo)

My 85GT did the same thing when I was tuning and had it to rich on the low end. Once I adjusted the problem went away.

I'd do a fuel pressure leak down test to see if you have leaking injectors. Shut off warn, it maybe leaking fuel into the engine and has to crank enough to clear it out first. Or you might try holding the peddle down to get into the flood clear mode and see if it starts up faster.
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phonedawgz
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Report this Post08-19-2012 10:45 AM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
+1 on the first thing to check is for a leaky injector.
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NetCam
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Report this Post08-19-2012 07:47 PM Click Here to See the Profile for NetCamClick Here to visit NetCam's HomePageSend a Private Message to NetCamEdit/Delete MessageReply w/QuoteDirect Link to This Post
Air filter is brand new, haven't checked the fuel filter, O2 sensor or cat yet. The problem has been there since I bought the car, and it's been throwing a 32 as well on the highway. Gas mileage is decent although not great. Is there a post anywhere on how to do a check for fuel injector leaks?
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Dodgerunner
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Report this Post08-19-2012 09:30 PM Click Here to See the Profile for DodgerunnerClick Here to visit Dodgerunner's HomePageClick Here to Email DodgerunnerSend a Private Message to DodgerunnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm surprised there is not a write-up in the cave.
You can either buy a pressure tester or borrow one from a parts store. Don't know what you have up North but Harbor Freight has a kit for around $20 if you want to own one. Canadian tires is a bit more expensive.
http://www.canadiantire.ca/...er+Kit.jsp?locale=en

You screw the tester on your fuel pressure schrader valve on the fuel tree by the thermostat housing.
Cycle your key without starting and you should hear the fuel pump run for around 3 second. You might have to cycle it a couple times or jump the fuel pump power on the aldl connector.
You should have around 42psi. The pressure should hold at that pressure for a half hour or so on an really good system.
If it drops off quickly or in 5 min. or so then you have some kind of leak.
You then have to determine where the leak might be. Possibilities are.
Fuel pump check valve, leaking injector(s), bad fuel pressure regulator, unlikely plugged fuel pressure.
If you don't get near 42psi, then bad regulator or fuel pump.

Checking -
Wrap locking pliers jaws with tubing or something to protect the rubber fuel line behind the engine. Clamp off the return line, (one without the filter) Cycle the key again. If you get more pressure then you regulator "might" be bad. OR If you get pressure and it still leaks down injectors are leaking, check valve is bad in pump or you don't have the hose clamped off well enough.
Next, with help cycle the key and also clamp off the supply line. Pressure drops your injectors are leaking.
Think I hit it all. If I wrote something wrong it will be corrected by someone I'm sure.

[This message has been edited by Dodgerunner (edited 08-19-2012).]

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NetCam
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Report this Post08-21-2012 11:33 PM Click Here to See the Profile for NetCamClick Here to visit NetCam's HomePageSend a Private Message to NetCamEdit/Delete MessageReply w/QuoteDirect Link to This Post
Got the Cdn. Tire version of the tester, it was actually the cheapest I was able to locate. Will be running the pressure test tomorrow and go from there. I was able to replace the fuel filter today so one less thing that could be the cause.
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NetCam
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Report this Post08-22-2012 10:49 AM Click Here to See the Profile for NetCamClick Here to visit NetCam's HomePageSend a Private Message to NetCamEdit/Delete MessageReply w/QuoteDirect Link to This Post
When I turned the car on, I got dead on 42 PSI, but after 5 minutes I got 38. Looks like I have a bit of a leak, but not a major one?





After a half hour, I'm down to 30 PSI.... I'm thinking this isn't good

[This message has been edited by NetCam (edited 08-22-2012).]

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Dodgerunner
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Report this Post08-22-2012 08:49 PM Click Here to See the Profile for DodgerunnerClick Here to visit Dodgerunner's HomePageClick Here to Email DodgerunnerSend a Private Message to DodgerunnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
10psi in 30 min. is not to bad but would depend on if that is leaking back to the tank or into the engine. The only way to verify it's the injectors is to clamp off the supply and return lines once at pressure and watch it. Or pull the injector tree and watch for leaking.
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notacityslicker
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Report this Post08-19-2014 10:50 AM Click Here to See the Profile for notacityslickerSend a Private Message to notacityslickerEdit/Delete MessageReply w/QuoteDirect Link to This Post
Any update on what fixed this problem?
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NetCam
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Report this Post08-19-2014 07:58 PM Click Here to See the Profile for NetCamClick Here to visit NetCam's HomePageSend a Private Message to NetCamEdit/Delete MessageReply w/QuoteDirect Link to This Post
Had one injector that had a minor leak. Fixed the problem by ripping it out and putting in a 3800sc
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Kevin87FieroGT
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Report this Post08-19-2014 08:55 PM Click Here to See the Profile for Kevin87FieroGTSend a Private Message to Kevin87FieroGTEdit/Delete MessageReply w/QuoteDirect Link to This Post
NetCam. You want to fix my car! That was the best fix I've heard of in a long time! No more stink'n 2.8L.
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