Help with FI.

Hi, I am asking for some help diagnosing a fuel injection problem. I havent worked on this system in many years and have a slow leak in my head.

77 type 2, 2 Liter engine, dragged it home after PO stored it for years, he bought it not running also. I replaced the air flow meter with a reman from Busparts, as the old one had the cover removed and then corroded and mice nested on the board. The cyl head temp sensor looks like it was replaced, still nice and clean. I changed the fuel filter and all hoses, flushed out the tank. New ignition parts, compression is only 85 PSI on #3, but i will not assume it's bad until lifters have pumped up a while. It tries to start but won't light, plenty of spark and noid light flashes. I disconnect fuel side of double relay and it fires up and runs til fuel pressure gone. With relay attached, runs to 39 PSI, and tries to light but if it does barely runs and dies when throttle pushed opened any. Disconnect relay, fires right up til out of gas. My thoughts are bad computer or defective air flow meter, but havent run resistance test on meter yet. Any clues?
Reply to
Stupendous Man
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Click on Library Click on "F" for Fuel Injection

Several good articles on troubleshooting.

See if the fuel system holds pressure when not running. Run the pump till max pressure reads (35-39 psi); should hold steady for 30 seconds or so (guess). If it bleeds off immediately, there is a leak.

Engine should run fine with 85 psi head.

Check resistance of head temp sensor; should read 2500 Ohms when cold (approx.).

The AFM is hard to measure and the readings may not mean much.

Make sure the Coil (-) terminal (#1) is connected to the ECU lead.

Check that +12V is getting to the ECU. Easy way is to connect meter to the ballast resistor pack (any lead). Should get 12V during cranking and with key in RUN position.

Speedy Jim

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Reply to
Speedy Jim

FYI, finally had time to look at it, easy fix. PO had installed a new head temp sensor, left it loose. No ground. Took 1/2 hour to diagnose and repair. Runs so good I may have to keep it.

Reply to
Stupendous Man

LOL

Thanks for the update.

Speedy Jim

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Reply to
Speedy Jim

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