Rice Killer87

Car is an all stock 1989 IROC-Z that my dad has, its been sitting awhile and we just got it running so he can try to sell it. We put a new fuel pump in it and now it runs....needs starting fluid for the first cold start but after its been running and you cut it off it will start on its own.

I havent messed with any third gens in a few years since I sold my 87 so im getting a little rusty....anyone have any ideas on what to check?

He did install a new temp. sender (not for the gauge) in the car and that didnt help it....dealer mechanic said that could do it but didnt help.

Thanks guys, and Happy New Year !

DAKMOR

did you make sure there was fuel to burn?

Gord's Green Z28

I had the opposite problem. Would start cold but not after it warmed up. Turns out it was my injectors. Ohm check them when they're hot. Should be 16-17 ohms each. (Mine were everywhere from 9-16 ohms, about half were bad. I replaced them all).

The stock injectors seem to be failing quite frequently in the 3rd gens. Just getting to be that time.

If it won't start without starter fluid when it's cold, it would seem that you have either a weak psi on the regulator (does it lose pressure fast after you shut the car off?), or weak injector pulses. But I'd check the injectors first. When those don't work, you'll get all sorts of problems.

quickchicken

wish i could find that thread where on a vette forum the fella ran the injectors and shown how they do cold and what happens when they get up to temp. he repeted the process after putting them in he freezer to cool them off and once again when they got up to temp some would hit and miss, others had less flow and so on, these were the stock injectors.
if yours are the stockers then its porobably time you changed them.

see what Rih can do for ya. when he ask you have 22 lbs if your car is a 350 or 19 lbs if its a 305. Rich is good people, he did mine and did a fine job.

Rice Killer87

Thanks for the info guys.

Havent gotten to work on it as we've been working (fortunately) until dark and its outside but will ohm the injectors in the next day or two...was hoping it wasnt them. Thanks Gord for giving me what the ohm's should be.

86camaro383

hmm I would look into the cold start injector. Its the 9th injector in the back on the driver side.

quickchicken

89 dosent have the 9th injector, 88 was the last year for that.
i agree with Gord, check the injectors first thing and check the timing as that can make a diff if its retarded or way advanced. the sticker on your hood will tell you what base should be.

cars3

I'm the secons owner of an 89 iroc-z 350 and there is a ninth injector and I've had it replaced for the same problem. Will not start cold. 1989 was the 1 and only year that had a ninth injector. 85-88 did not have them, and there was so many problems with them that in 1990 they did not use them. Oh and to the people who want to disagree I have a 1988 firebird formula that is all stock with a 350 and there is not a ninth injector.

quickchicken

89 does not have the 9th injector. my 89 formula dosent have one and they ran from 85-88 on the 9th injector, this is one of the reasons i avoid any TPI from 85-88. 85 esp since it has a weird MAF situation that they changed in
86, go price the MAF and you will see what i mean. my friend learned the hard way when he dropped his.
everysingle pre 89 car iv had my hands on had the 9th injector and vice versa for the 89+ cars. if you have a 88 and older car you better check the VIN if it dosent have a 9th injector as its ither a mis read vin or someone pulled the supply hose, cappped it off and changed the bin file to a 89 which is TOTALLY possible.

raul.garcia

Guilty

My '88 had the cold start injector. I switched to an '89 bin and deleted the injector, fuel supply line, and plugged the fuel rail & injector port in the runner flange. i didn't delete the cold start temp-timing sensor thought I could use that for something else some day.

Also guilty of:

Deleting the TB coolant, yes deleting vs bypassing.

quickchicken

Raul thats pobably the best thing you could have done for your system. a friend of mine out west had a car in his shop and called me to see if i knew anyone that had a replacement injector because the one in the car he was working on went south.
thats exactly what i would do if i got a pre 89 car.