When cold,ie... sits all night, the engine starts instantly. I have eliminated the ignition system as a potential source for the problem by substitution and other means so I feel it must be the injectors.
A fellow was telling me that the solinoid in the injector gets dirty and takes a bit more juice to loosen-up, as they age. My injectors are OEM circa 1985 and they sat in my shed from 1990-1999 when I built the engine. I have had this problem since the first time I started the engine. I do not know how well the system worked before this because I bought the engine second hand in 1990 and disassembled it right away.
The guy that informed me about the solinoid said that I could compare the resistance through the injector when it is hot to when it is cold and that a "big" difference between the two would be a dead givaway that it is the problem.

one other thing, When hot, if I crank the engine over for just a second and stop and immediately crank it again it fires right off....

Can anybody refute this information? sorry about the long post......'84

------------------
'84Z28/'92 305TPI
'92 complete rear suspension/PBR disc/Posi/3:42
Light weight 34.5mm stabilizer bar in front ($10 from wrecking yard)/
"wonder Bar" ($5 from wrecking yard)
23mm sta. bar in rear
Rear RS Springs (slightly softer than my Z28)
comp cam, flowmaster
TB coolantbypass/shutoff valve to heater core
powersteering cooler lines (liberated from another wrecked car of course)
MAT relocated
Ram-Air(home-made) gutted air-box
IROC ground effects/wheels GY245/50's
700R4 superior shift kit/ corvette servo(excellent shift kit btw)
home-made strut tower brace (cost $6)

Rebuilt engine and transplanted it myself.

Love this engine!

freshly painted OCT. 2000 Teal with two white stripes on the hood and deck lid

LOW performance people should drive low performance vehicles!

[This message has been edited by 84IROC (edited April 16, 2001).]

 

Come on "Tech-Gurus" and ASE Techs, any ideas on this, slow-to-start when hot, Q!

The starter spins the engine over very fast but the engine fails to fire off right away, only when hot and only after it sits for longer than 5 minutes........

 

Sounds like leaking injectors to me. Does it smell like unburned gas right after the hard start?

------------------
1988 GTA 5.7L TPI Auto
355 ci. block,TPIS ZZ-9 Camshaft, SLP Headers, Borla Cat Back, B&M Holeshot 2400 Stall Converter, 3.73 Richmond Gears

"Why ride a stang when birds can fly?"

http://www.geocities.com/thegta

 

JO
no, it does not and I have checked for injector leakdown and its not that. I may be wrong but I do not believe it would start instantly when it has been sitting for a long time if the injectors were leaking.

thanks again for the reply.....
'84

 

IROC,

Your symptoms certainly sound like a rich start after heat soak. The common problem in TPI systems experiencing this problem is one or more leaking injectors. Since you have apparently tested the fuel pressure and have determined that the injectors are not leaking, we can eliminate that possibility. It is possible, however, that the cold start control is failing, and applying extra starting fuel from the ninth injector on restarts. You could eliminate this possibility be unplugging the electricla connector from the cold start injector. This may make starting while cold a little more difficult, but should help diagnose the problem when hot.

It's also possible that the EVAP canister is saturated with fuel, and one of the control valves is sticking open, allowing the vapors to waft back into the intake causing a rich condition.

If the problem is excessive fuel as is suggested, you can offset this by holding the throttle open partially while cranking. If this allows for faster restarts, it almost certainly points to fuel percolation or leakage somewhere. Another sign of excessive fuel on startup would be a puff of smoke (other than blue oil smoke from valve seal leakage) on startup when warm.

I have had no experience with "sluggish" injectors when hot, but if you want a more definitive answer, check with Cruzin' Performance for expert advice.

------------------
Later,
Vader
------------------
"What a Day..."
Adobe Acrobat Reader

 

Vader,
No ninth injector (system was rewired for 90-92 spec).
EVAP cannister in new.
Cracking the throttle partly open does not assist in the start-up.
No puff of smoke on initial start-up.

thanks for the reply, I'll keep on look'n............'84



------------------
'84Z28/'92 305TPI
'92 complete rear suspension/PBR disc/Posi/3:42
Light weight 34.5mm stabilizer bar in front ($10 from wrecking yard)/
"wonder Bar" ($5 from wrecking yard)
23mm sta. bar in rear
Rear RS Springs (slightly softer than my Z28)
comp cam, flowmaster
TB coolantbypass/shutoff valve to heater core
powersteering cooler lines (liberated from another wrecked car of course)
MAT relocated
Ram-Air(home-made) gutted air-box
IROC ground effects/wheels GY245/50's
700R4 superior shift kit/ corvette servo(excellent shift kit btw)
home-made strut tower brace (cost $6)

Rebuilt engine and transplanted it myself.

Love this engine!

freshly painted OCT. 2000 Teal with two white stripes on the hood and deck lid

LOW performance people should drive low performance vehicles!

 

one more time, anyone have any more suggestions? thanks in advance............

84