warm starting issue

[honerboys]

i've seen this posted for the early CIS cars but mine is an 84 - car used to start when cold in about one revolution on the starter but when warm it would take 20-30 seconds - well this has gradually gotten worse - now it takes about 20-30 seconds when cold and last night it took me about 3 -4 minutes to get it to catch - i changed out the FI relay,,no effect - i can hear pump running - last night after it caught and i drove it home i smelled gas - tried to trace it and it seemed to smell the most in the passenger front wheel well - is that where the carbon canister is - i had changed out all the fuel lines 2 years ago and none look like they are leaking now - so.. what do you think is going on? - leaky injectors might explain the hard starting but not the gas smell - once it starts the car drives great - no stalling or hesitation - could the check valve on fuel pump do this? - i had cleaned the ground points but that was also 2 years ago - would they have corroded again that fast? - thanks

[Mrmerlin]

I would replace the 3 way junction in the RF wheel well, thats whats broken.
also time to remove the rust and metal collars in the washer fill tube and tank inlet, drain the tank out.
Most likely your fuel pump check valve is leaking, order and new check valve, it comes with the 3 sealing washers,
a fuel filter if yours is old,
and the short hard line from pump to filter.

I would also suggest to run a bottle of Techron and 6 oz of MMo in the fuel,
also check the dampers and FPR for the fuel smells in the respective vacuum lines

[honerboys]

hey merlin - thanks for the info - i checked that 3 way plastic connector - it appeared to be ok and all hoses were tight - i replaced the check valve on the pump even though the old one seemed to still be working - when i loosened the banjo junction there was plenty of pressure in the line up to the engine - what regulates that pressure and decides when it's enough and returns the excess to the tank? - is that the job of the left or right side fuel pressure regulator or do they work in tandem, with one monitoring the left bank and one the right? - it still starts hard when warmed up - i did notice that if i shut it off for less than 5 minutes it starts easily more than that and it's harder to start - i'll check for fuel in those vacuum line next - also i might try adjusting the idle mixture screw as the exhaust smells a little too gassy - or it could be leaky injectors - i did run a bottle of techron through it last year - didn't notice any difference - another thing maybe unrelated is the idle surges a bit - 50 rpm or so

[stepson]

Honer,
Check your temp II sensor. Faulty Temp II can make your car really hard to start. It's easy to test and easy to access.

[honerboys]

i know it's been a while since i posted on this - the car hasn't been getting driven much - it had a coolant issue and winter and other stuff going on - the warm starting problem really isn't that much of a problem as the car runs great, but i'm going to try and address it now

i removed the runners and checked all vacuum lines - they seemed ok - put it all back together - now it seems to start harder whether cold or hot - so i checked the usual suspects....

temp time switch for cold start valve
temp sensor II
aux air regulator
cold start valve

the results of my testing has me wondering how all these interact with each other - here are the results

temp time switch...when at 80 degrees F
w-ground ... .06 ohms - manual spec..0 ohms - i called this one ok
g - ground...36 ohms - spec...0 ohms - so this looks bad
w-g...36 ohms - spec...20-40 - looks ok

temp time switch at 180 degrees F
w-ground..143 - spec 100-160 - so ok
g - ground..70 - spec 160 - so bad
w - g...74 - spec 50-80 - so ok

temp sensor II at 80 degrees F
1994 ohms - spec at 68 F is 2-3 K ohms - so my temp being slightly higher i called this ok
temp sensor II at 180 degrees F
197 ohms - spec is 250-400 ohms - so too low

cold start valve at 80 degrees F
resistance across valve..4.1 ohms - spec is approx. 4 ohms - so ok
now there is a test for power to this valve below 86 degrees F ,which it was, but i got no power to this switch with ignition turned on or with the engine running at this temp - so when they say below 86 degrees is that an absolute or might this be working at say 75 degrees - i don't know

aux air regulator at 80 degrees F
resistance across valve 17.8 ohms - spec is 40-75 - so bad
i did get power to valve with ignition on - i know it says to bridge the fuel pump relay but is that different than just running the pump with ignition on?

so the time temp switch has bad readings for G to ground.. both hot and cold
the temp sensor II seems close hot and cold - off reading hot could be my temps are not exact
cold start valve had good reading but no power with ignition on - so would it be that sensitive to a few degrees - i will have to try and catch it when the outside temps are cooler
aux air regulator is off on reading - so bad??

so if one of these items are bad what effect would it have on the others - which one should i replace first? - thanks in advance

[stepson]

Temp II is easy to access and relatively cheap. They do fail. I think I might start with that one.

Temp II communicates with both the EZF and the Injection computer (L-Jet in your case, I believe)

[honerboys]

hey stepson - i got advice on the other forum that the temp time switch is what directly controls the cold start valve - i got some bad readings from that switch so i'll probably just replace both the temp sensor II and that switch - the one that really was off was the aux air regulator - not sure what it's function is and i see it's $$$ - i'll test it again but i hope i don't need one of those

[stepson]

Honer,
I saw those numbers, but I also know the Aux air regulators are not cheap. I was headed toward the easy and cheap route first. If you find that you need a different Aux air regulator, let me know and I can put you in touch with a guy local to me that has used parts inexpensive, (or call 928 INTL).

[honerboys]

will do - thanks

[Opelotus]

AFAIK, the aux air valve shouldn't have much, if any effect on fueling during startup. It's really just there to increase the idle speed when the engine is cold.

The thermo time switch can be unplugged to disable the cold start valve. Maybe unplug it and try starting hot/cold and see what happens?

Leaky injectors can definitely cause hard starts. My '84 had that issue and it was worst when the engine sat for 15 minutes or so after getting up to temperature. I was able to smell fuel vapors from the airbox area when this was the case.

Like Stepson said, just throw in a new Temp II sensor regardless. Cheap preventative maintenance.