Hi All,

 

Firstly I appoligize if this is a repost but I'm slowly losing my mind. Neighbour has a 1988 GL wagon, 5 speed 4wd. Did a tune up, replaced the plugs, leads, cap and rotor. Did the fuel filter, air filter and replaced the fuel pump that had died.

 

The issue and what I have done so far.

 

Hesitates under load badly.

 

I have replaced the fuel pressure regulator, idle air control valve with a known good part, throttle body, all the venting tubes. The only way I can get the car to run properly is to clamp the return fuel line to tank.

 

I have checked the timing and it is right on now that I have fixed all the vacuum leaks. The only thing I can hear that had me slightly baffled is the fuel pressure clicking on and off every 5 seconds.

 

Was hoping to get some advice before I went out and spent 200 dollars on new fuel pressure dampers

Did you pull the PCV valve off and clean it out with some brake cleaner? That does wonders sometimes.

...

I have checked the timing and it is right on now that I have fixed all the vacuum leaks. The only thing I can hear that had me slightly baffled is the fuel pressure clicking on and off every 5 seconds.

...

Sounds to me like the green diagnostic plugs are connected, which, among other things (such as holding ignition timing constant), also causes the fuel pump to cycle every 5 seconds or so.

+1 on the green diagnostic plug. Check to see if someone has connected both the green and white plugs by the wiper motor, drivers side fire wall. These should remain disconnected. I see this alot around here, the meth heads just can't leave things like that alone.

 

Mark

If the plugs are correct, run a fuel pressure check and you will probably find a bad / wrong fuel pump or possibly still a bad regulator.

Edited April 16, 201312 yr by silverhelme

As already mentioned, disconnect the plugs under the dash and hopefully that will solve the problem. The plugs have just one wire going to them and they make a ground connection to the ECU. They are only to be connected when trouble shooting.

the tbi injectors wear to the lean side mabee injector is on its way out or cam timing +1 green diognostic conector thiss will hold the timing at 0 and not lett ecu addvance timing

As already mentioned, disconnect the plugs under the dash and hopefully that will solve the problem. The plugs have just one wire going to them and they make a ground connection to the ECU. They are only to be connected when trouble shooting.

Since this sounds like an SPFI car, I believe that the connectors would be in the engine bay next to the windshield wiper motor.

the tbi injectors wear to the lean side mabee injector is on its way out or cam timing +1 green diognostic conector thiss will hold the timing at 0 and not lett ecu addvance timing

The diagnostic connectors will fix the timing at whatever you set the distributor, not at 0degrees.  It essentially disables ECU timing adjustment (amongst other things)..

opps my bad as long as he gets the point

opps my bad as long as he gets the point

Yea, same unpleasant result.