88 IROC - 5.7
Have to crank at least 15 times to get it to start.
Once started will restart ok unless sits for few hours or over night then its back to wearing out starter / bat
Have changed plugs, wires,cap,rotor, fuel pump relay,filter and set timing to 6 BTC. Firing order good.
SES light has been on for a while but it never did this start thing.
Hear fuel pump initialize and it was changed about 3 years ago.
Checked vacuum and wires for obvious stuff.
Temp gauge will not read most of time.
Where is the CTS and how to check.
If it is a fuel pressure thing where do I start.
Measure volt to pump ? HOw and where
Check fuse - where is it located.
Fuel pressure - where and what type of gauge
Need some help please
Thanks JCee

 

Fuel pressure....go to Autozone, Advance Auto, etc. Get a fuel pressure gauge for fuel injected cars....one for carbs wont work, you'll blow it up. On your fuel rail, there's a test port on it, known as the Schrader valve. It looks like a valvestem for a tire. Take the cap off of it, if it's on there, and screw the proper fitting onto it after it's all attached to the pump. Oh....and do the test before you start the car, so you can pinpoint if it's not starting because it's not priming properly. Have a buddy turn the key forward, and watch what the gauge does. It should get up to about 40 psi or so if I'm not mistaken. 35 will probably be ok. Anything say, 30 or less, and you might have a problem. Then, turn the key off and watch the gauge. Wait for a good 5 or 10 mins....look to see if the gauge starts dropping. If it does, that means you're losing pressure in the fuel line...which means a leak somewhere. Most likely an injector leak.

Don't bother with the fuel pump fuse. If it was blown, your fuel pump would not work at all.

Does it blow some black smoke when it starts or does it start clean? How's the car run after it starts... Any bogging or low rpm hesitation?

Also, have you ever pulled the code for the SES light?? That might help.

 

Low idle or lets say rough idle and stubbles between idle and say 1500 from the tach.
Don't see the black smoke when fired but will check again when sits next time.
It comes up to 1500 sits for few seconds and then falls off to say 700 -900 on tach
I hope i timed it right / disconnected the right wire when setting timing - it was located above heater box - single weather protected connector out of the loom. Tan with black stripe
I checkd timing when connected and bounced around but when disconnected was solid - strange it was about 6 ATC ie on the down side of the degree plate. Didn't seem to make a difference.
Unplugged and plugged back in with motor off and disconnected bat _ neg term- before refiring.
Kicks out the MAF code but it as been changed and seems to be an issue with the burn off circuit
- I'm stumped but determined to understand
Would the ignition switch play a role - it's loose in column ?
- it's got 170K mi
Thanks

 

Car should've run like holy hell being at 6 degrees AFTER. I imagine it wouldn't run at all..

Sounds like you're either not reading the timing right, or there's something in there that's wrong. Maybe if you try playing with the timing you can get it to run right. If you bring it CLOSER to top dead center, I imagine the idle would get lower and sloppier and the car would try to stall. If you bring it FURTHER from TDC (aka more advance), the idle would probably steady out...if you overadvanced it, it would start to ping...but shouldn't try to stall. By using those indicators, I'd play with the timing...get it advanced til it pings, and then drop it back about 2-4 degrees. See how it runs then.

I had that problem too. My Camaro read 6 degrees BTDC timing, even though I KNEW I set it at 10 degrees earlier and it never got changed and ran fine. I assume something on my balancer spun somehow.....

 

Fuel pressurrre check
fuel pressure ckd at 36 with key on - came up right away.
Engine idling reads between 36-38, little bounce/pulsey
When revd goes to 44 then drops to 32 when backed off
When shut down reads 44 and holds for 10 min
drops to 30 after total 20 min.
will let it sit over night and ck press in the am

I understand advance as BTDC - retard ATDC - correct.
What should it be with ETC active ? I know it will bounce
Thoughts

 

Your fuel pressure test sounds fine. Overnight it will probably drain to almost nothing.... The system does normally drain itself of pressure...it's just if it starts dropping immediately, you know you have a leak. If it holds at 40+ psi for over 10 minutes, it doesn't sound like there's any leak there...

If I remember right, the ECT will generally add about 20 degrees of advance... But it'll bounce around by a few degrees. It should probably read in the 25 degree advance or so range at idle...

Advance...yes, that's before top dead center. Retard...yes, after top dead center, BUT you'll never hear it used like that because no motors, at least none I'm aware of, run on AFTER top dead center timing. They all spark first. That way they can ignite the mixture a split second before the piston reaches the top, so that when it does, it'll aid with the detonation of the mixture and it will push the piston back down immediately. Running AFTER top dead center on your spark would mean the piston would hit the top BEFORE the mixture was ignited and the mix would ignite as the piston was on its downtravel, where it would lose velocity because it didnt receive the extra push and the mixture would dissipate too quickly to burn properly.

 

Thanks for the trading of info.............
SO now that the fuel is considered ok and lets say the fuel press is good in the am
what the hell makes it hard to start ...
Any relays that would prevent it from wanting to fire
or sensors that the ECM is looking for a "ready"
I've put 100K on it with no sensors changed
Guess I'll pull # one and see if getting spark
I 'll search for how to read codes -

Again.. thanks for suggestions

 

How to check for codes: https://www.thirdgen.org/newdesign/faq/thirdgen.shtml

Go to Miscellaneous, it's the first part in that section.

I dont believe any sensors or anything have a part in cranking..it's just fuel and spark... The computer ignores all the sensors and emissions and often richens the A:F ratio to get it to start.. Dont see why it wouldnt want to start if it's getting fuel and spark....doesn't make much sense to me. Try a spark check in the morning, when it doesnt want to start. See if you're getting anything.

 

The CSI could be going bad or is bad.

 

Thanks
I show my ignorance
what and where is the CSI ?

Ck'd out this am
Fuel press right away to 42ish
Getting spark - gut feel says don't look right - intensity wise
used old plug out of harley.
Reading codes 34 and 42
42 when I disconnected EST - should clear
34 MAF but it was changed sometime ago.......
doesn't that also mean ign intermittant ?
So after code read still several cranks to fire up
Cleared codes and nothing with about 5 start ups
Will take for a spin
Thanks fo rthe help
Later

 

Found the cold start inj stuff
does anyone know if the ohm reading really should be apprx 4 ?
what voltage should be present ?
Thks JCee