squareone206

Does anyone knoe how the cold start system works on a 89 Iroc TPI it does not have the 9th injector like 85-88.......it does still have the MAF and not the MAP setup so does any one know how this system works? is there a something that make it spary more fule? My car has a hard time starting when it is not worm it will start right up once it is wormed up..........

Thanks

fire350tpi

it just richens the motor through the primary injectors

squareone206

Ya but what makes it work? mine is not working right and I need to know how to fix it... so my car will start right up when it is cold....is there a sencer theat needs to be changed or dose the ecm need to be looked at how does the whols system work so I can try to trobule shoot the problum and not change alot of stuff that has nothing to do with it.....?

GregWestphal

iTrader: (1)

There is a table for open loop fuel vs. coolant temp. For the cars with a 9th injector, the table was flat, IOW, the same value for all coolant temps. For the '89+ cars, the values were much higher at lower coolant temps. It sounds like you have a malfunctioning coolant temp sensor. I'd check everything with a scan tool first before replacing parts...

BTW, it's "warmed up" not "wormed up".

Ed Z28 350

You are assuming that your problem is in the injection. It could also easily be in the ignition system as well.

As to your question, the car basically squirts more fuel out of the 8 injectors at cold start up. As long as your engine sensors are in good condition (intake temp, MAP, coolant temp, etc) then the computer should be able to properly handle the enrichment.

Something else to look for: is your injection system holding pressure overnight? I forgot the name of it, but there is a valve either in or near the fuel pump that prevents pressurized fuel from bleeding back into the tank. That valve and your injectors must be able to hold pressure, otherwise the system will need to prime itself every time you start the car after sitting for a while, leading to hard starts.

D's89IROCZ

Any codes ? Is the check engine light ...lighting up ?

squareone206

I will have to check that thanks for the gramer check
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no codes and the SES light does not stay on

squareone206

I will check this out and let you know......the car does not have a MAP sensor it has a MAF only 89 has MAF w/o the 9th injector for cold start.

what do you think could be wroung with the iginition system

toddztoyz

I second the coolant temp sensor too. I had a problem with it not turning off the cold start so I was getting a code 45 (rich exhuast). $8.95 later I was back running good again.

BTW, It is the sensor in the front of the intake directly under the throttle body. It is a real bastard to get out too.