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?
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

Stupendous Man wrote:
> 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?



http://www.type2.com/
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
http://www.nls.net/mp/volks/

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.

Stupendous Man wrote:
> 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.


LOL

Thanks for the update.

Speedy Jim
http://www.nls.net/mp/volks/