89 Ford Festiva fuel injected idles fine in park die in gear set for a year bad gas put Premium and fuel treatment in it new distributor cap and button im at a loss dont know much but not afraid to w
Asked by fordrunning101 Jul 17, 2015 at 09:12 PM about the 1989 Ford Fiesta
Question type: Maintenance & Repair
13 Answers
fordrunning101 answered 9 years ago
Getting good fire vac looks and sounds good thre is a spot taped but not leaking and not check engine light
I would also replace the fuel filter. Buy some throttle body spray and spray down the inside. Check the air filter and make sure there's not a mouse nest under the air filter. Post back with results.
Fire it up.. hold the brake put it in gear and open the throttle. . In other words load the engine down.. see if it stutters or misses.. I'm thinking you got a fuel starvation issue.. with ought proper diagnostics this may be difficult to diagnose.. what color were the plugs? Black? Or amber? Or white? Keep in mind black is rich. Amber optimal more white to lean.
Don't just throw parts at er boys.. let's diagnose the issue it's cheaper. Process of elimination.. u may not have needed the cap and rotor. Or plugs.. there's a 100 bucks gone and u still have the issue. Right?
fordrunning101 answered 9 years ago
Thank you all i will be working on it tomorrow all day so i hope one of these work
Can you get access to a fuel pressure test kit.. ? If you got spark assuming the timing is correct. Then your either over fueling or under fueling..
Disconnect your coolant temp sensor .. this will put the pcm into limp mode. It will trigger open loop operation or cold start up procedure also it will shorten the injector pulse width causing a rich mixture. Repeat my first test . Load the car down in gear and see if u get fuel cut.. Second does it hesitate when u open the throttle or closed. Open is a sign of under fueling..example.... if your car is running rich ideally when u open the throttle it should smooth out as u allow more air in.. if it's under fueling then it will run ok at idle but as soon as u allow air in it will trigger a lean mix. Then your pcm will try to compensate and shit gets bad.. I usually just watch the Mas tps and up stream o2 on an oscilloscope. . But you don't have my equipment.
Also and this is not a fix.. nvr use this as your fix.. only a test.. take a pair of needle nose vice grips snug them onto your return fuel line. Don't pinch the line . Just close it a bit. This will help diagnose a faulty fuel pressure regulator. It will raise the fuel pressure in the rail.
Haha my god boys this is like working on a carburetated car.. i wish u could get to my shop. I could diagnose this in minutes.