First time posting. Hope my etiquette it correct.

I have a 1989 SE-i. Won't start when hot. I've already dealt with the Fuel pump relay problem. Engine light comes on, pump comes on and light goes off when the system is pressurized. No CEL codes. Starts fine when it's been sitting for a few hours. When it's been running and then turned off, then it won't start. But this seems to be somewhat intermittent. It will start and stay running if I spay some starting fluid in the intake.

Also when the engine is warmed up it falters when put in gear. Then it recovers to a normal idle. Also falls flat on it's face when you put slight pressure on the throttle, in gear or in neutral. Then it recovers and runs fine going down the road.

From reading this forum, I'm thinking of getting a fuel pressure test guage to make sure I really have fuel pressure. Also may try to test that the injectors are getting their electrical signal. Not sure what to do though if they're not.

Any ideas on this would be great. Thanks.

 

Just so I'm clear.

When it won't start, is the starter spinning the engine over?

The fuel filter is really easy to change and doesn't cost much.

 

Yes, engine turns over and over. Just doesn't fire.
I put a test light on one of the injector plug wires. It has a signal, even though the engine is not firing. Thanks for the suggestion on the fuel filter. I'm leaning toward fuel being the issue. I'll do the filter first to see if that will make a difference.
I also bought new plugs, wires, rotor. Just to start eliminating possibilities. Also went to the wrecking yard and picked up a throttle body and cold start injector, ECU, and the two temp sensors that go in the housing next to the head. Hoping to have time this weekend.
I'll update the post if I learn anything.
Thanks again.

 

How exactly did you use the test light on the injector? The injectors are all powered constantly. The ECU switches the ground side of the circuit. So if you put the test light from (+) to ground, you see that they have power. But if the ECU side of the circuit is disconnected you have to connect the test light wire-to-wire on the injector.

 

I unplugged one injector and touched my test light wires to the two contacts inside the plug (wiring harness side). Had someone crank the engine. My light flashed. Figured I was getting a good signal at the injector plug.
Is that not a good test? Constant power to my light from one wire in the plug. Light goes on when the ecu completes the circuit back to ground via the other wire in the plug when the engine is cranking over.
Please let me know if I'm still not understanding this correctly.
Thanks

 

That sounds correct. One side is "hot"/battery voltage at all times. The ECU, through other systems, sends the ground when it wants the injector to open.

So the injectors are getting the signal to open - Check that off the list.

 

Replaced the plugs, wires, rotor and fuel filter with new.
Replaced the 2 temp sensors with wrecking yard parts.
Still same symptoms. Starts and runs when cold. Bad hesitation and won't start when warmed up.
Swapped out the ECU with a wrecking yard replacement.
Runs like a champ. Life is good. Never did figure out exactly why (ie. Spark, Timing, Mixture, Fuel, ????) ECU was $30 at the wrecking yard. Other parts were about $60 and it was due for that stuff anyway. Turned out to be a good day!

Thanks for your input. Happy motoring!

 

Good to hear....

THANK YOU for the follow up. Too many times we never know how things turn out.