b787tech

I have searched threads here & I find many that speak to the same trouble I am having which is the engine turns over but wont start. This car has had some history of this over the years but it was very in frequent.
This car has been setting for a couple years now & I wanted to get it running to sell it. Because of the intermittent no start history, with ignition, air and other basics okay, I went for the fuel pump. I didn't do any diagnostics, because sometimes your just lucky- (I know). However the fuel pump wont run with key in on or start position. I went to the main relay next & performed voltage / continuity checks. The FP relay is not closing as it's missing the ground through the FLR1 A7 pin on ECM "A" connector. I replaced the main relay precautionary, but no help. I can make the fuel pump run by jumping the green-yel wire to ground, but still no start. So I have read through many posts about this & tried to follow the logic but at this point all to know avail. I suspect my problem is the ECM, but I'd like to verify that before I spend the $ as the car is not in the greatest shape. Here's what's been done to this point.
Basics
Battery fully charged - Ground connections at Bat & Thermostat ground cluster removed cleaned & tightened.
New Fuel pump- all wiring & connector are good to the Main Relay. Fuel Filter new. With pump running I can here fuel in the injector rails on top of engine.
All related fuses checked good #24, #18 under dash & #31 under hood. Have Batt Volts on one side of #31 with fuse out.
Main relay, replaced- Batt volts present at the Yel/Wht wire- Batt volts present at Blk/Yel wire when switch to ON or cranking. Blu/Wht has power only when cranking.
Colum Ignition/start switch checks
Verified column IGN switch position check using Honda table, all chks good except the "Key In" position is kind of worn & the beeper is intermittent. All the positions otherwise are good (Bat Volts & or Continuity)
Verified IGP1, IGP2 Conn A25 & B1 has Batt Pwr,
Verified PG1, PG2 Conn A23, A24 to ground ok.
FLR1-FLR2 Conn A7 & A8- NO Ground- Temp Jumper installed to Ground - Fuel Pump runs with key on
LG1 - LG2 Conn A26 & B2 have continuity to ground.
Other Tests/ Checks/ Observations
Check MAP Sensor = 5V supplied Good
Checked for spark at one plug & off of Coil secondary- Have spark- The Cap & Rotor were recently replace- engine was running at that time.
Tried using starting Fluid & engine is trying to fire, but never gets it to start or run even for a second or two.
CEL- on steady- wont go out with key to on. Jumper the code reader connector- light stays on steady- no flashing codes.
Removed ECM- Carefully open & Inspect inside covers, no signs of Arcing, burning or corrosion. Connectors & pins all look good.
Next step? Put it together & call "Cars for Kids"?
Any suggestions are much appreciated.

JRCivic1

Borrow an OBD-1 ECU from a friend and plug it in and see if the car will crank and run... it may not run perfectly, but this will shed light on the idea that your current ECU is good/bad.

b787tech

No option to borrow - Anyone know logic of FLR1-2 for A7 & A8 switch to ground? What conditions must be meet?

mk378

The main relay is turned on by the ECU puling that wire to ground. The ECU will do that for the pump prime after boot up, and when it sees that the engine is rotating. If the engine is running and it stalls out, the ECU will turn the pump off. This feature is likely for safety in case of a crash.

If the CEL stays on steady, and you're sure the main relay and the power and grounds are all good, it is usually a bad ECU.

If you don't have a known good ECU to try by substitution, try leaving the key on for several minutes to see if the ECU ever boots up. The pump would prime and the CEL goes out, and you could start the car. This means there's a bad capacitor in the ECU.

b787tech

https://www.ebay.com/itm/OBDI-Honda-...tor-Repair-Kit. Hoping the supplied instructions in this kit will identify the correct CAP to replace.