Check Engine Light still on...
 

So I had a check engine light on after I fixed the blown head gaskets... After some advice here and research online...

It lead me to replace the O2 Sensor and Coolant Temp Sensor.... The replacement Coolant sensor I received was a single wire like the factory one except it had a spade connector instead of a round one? I sliced a traditional female spade connector onto the wire...

CHECK ENGINE LIGHT STILL ON... except the car runs for a few seconds before it turns on?

Anybody got any ideas?

Thanks for your help..

Steve

Check engine light means it has thrown out a code or two, have you checked for any?

I originally scanned it with an old MT2500 Code Scanner and it showed "Coolant Temp Sensor" was out... So I replaced both the Coolant Temp Sensor and the O2 Sensor...

It showed the check engine light on, only this time the car runs a few seconds before it comes on... Where before it was on right away as soon as you started it...

So I re-scanned it again with the Snap On MT2500 and it showed no codes this time?

I also unscrewed the Gas Cap thinking that might be it... Still Engine Check Light... Then tightened the cap and still Engine Check Light...

Im stumped now...

Thanks for your help..

Steve

Since you fixed the code. Try disconnecting the battery for a couple minutes. See if the engine light comes back now that the code is fixed.

Ive unplugged the battery numerous times between tests... and still the damn "Check Engine Light" keeps coming on...

Its driving me crazy...

LOL

Steve

Can you hook up a fuel pressure gauge after the fuel filter? You should see
about 13 psi as you start it up. May be a clogged filter. If your pressure is good
and then it stalls, do you still hear the fuel pump running?(I know you said you already replaced the pump).

If your pressure is less than 12 psi, move the gauge back between the filter and gas tank to make sure your filter isn't clogged.

If the filter is good then I'd suspect your low pressure is due to a bad fuel pressure regulator. It's located in the rear throttle body. Rebuild kits are available from Auto Zone, O'really and other outlets. Make sure it contains the diaghragm for the regulator.

Remember that CD Field Manual I sent you? Look in the electrical manual
and illustration 8A-21 and 22 show all the schematic for fuel pump.

Page 8A-18 on the right side of the page, is "How to get codes". I know you used
a code reader, but manually using a jumper has found me codes when the tool didn't. do you get a repeating of MORE than 3 sets of 1-2? (no codes available)?

Finally back to working on this thing...

Did the "paper clip A-B code reader" method and all I got was code 12.. So no help...

I then replaced the ECU with a re-manufactured unit and same result...

I did notice:

A slight popping through my exhaust
My electric cooling fan is not coming on...

So now I'm REALLY STUMPED...

Thanks for all your guidance so far...

Steve

Check to see if timing is off.

Will low fuel pressure trigger the "Check Engine" light?

My car will not start without using some gas or starting fluid in the throttle bodies? Im going to do a fuel pressure check as suggested as soon as I get a chance.

When I turn the key I do get a quick squirt of fuel, but not enough for it to start?

When it is running there is the desired "cone pattern" from both injectors.

I replaced the filter and fuel pump with a pump for a 1984 Corvette. There are lots of posts about using the 1985 and later Corvette pump? What are the modifications needed to use it? Wiring?

Thanks,

Steve

I ordered a Racetronix pump back in 2014. Easy installation. Works just like it should!

They have an 84-85 upgrade KIT which includes pump, filter sock, rubber gasket for
pump-to-tank mount and brand new mounting bolts!

Racetronix - Chevy - Corvette C4

Click on " Chevy-Corvette C4 Racetronix " link and go down 5 or 6 items to the kits.

I ordered the FPA-009 upgrade. The FPA-009H has a higher 225LPH delivery volume but
the 009 has more than enough volume for a Crossfire. Remember,
fuel pressure is determined by the fuel pressure regulator, not the pump.

Thanks for the link to the pump...

Will low fuel pressure trigger the "Check Engine" light?

Thanks,

Steve

Not with OBD1

Low fuel pressure won't trigger but I believe "misfire" will... which could be an indirect result of a fuel problem.

Try to check the pcv connector if there's any crack.

Guess its not the fuel pump...
 

I finally got a chance to work on the car again!! I put a fuel pressure gauge in line between the two throttle bodies and get between 15-17 Lbs of pressure with the car running....

So now I still have the "Check Engine Light" and it is hard starting sometimes I have to pour a small dash of fuel into the throttle bodies but then it starts right up?

So now Im wondering if it could be my MAP sensor or the IAC valves?

Any help you can provide would be great as Im at a loss as to what to do next?

Thanks,

Steve