87 escort fuel system problems

[jasonburklund]

I have a 1987 Ford escort wagon, 1.9L CFI Throttle body fuel system. My problem is that at about 1800-2500 rpm, my injector is dumping so much fuel that my car stalls. Any rpm higher or lower than that, it seems to run fine. I have replaced all of the fuel system components( fuel pump, fuel filter, fuel injector, etc), but still have not cured the problem. If anyone has experienced this problem, and can tell me what to do, please respond to this message? Thank you for your advice!

[A. Souphound]

Originally Posted by jasonburklund

I have a 1987 Ford escort wagon, 1.9L CFI Throttle body fuel system. My problem is that at about 1800-2500 rpm, my injector is dumping so much fuel that my car stalls. Any rpm higher or lower than that, it seems to run fine. I have replaced all of the fuel system components( fuel pump, fuel filter, fuel injector, etc), but still have not cured the problem. If anyone has experienced this problem, and can tell me what to do, please respond to this message? Thank you for your advice!

Jason,
The throttle position sensor, mounted to the throttle shaft on the side of the fuel charging assy. could be causing the problem. The sensor sends a signal (variable voltage) to the EEC processor that varies with throttle position. The processor reads the signal and determines whether the throttle is closed, part or full open. The processor uses the information to regulate fuel mixture, ignition timing, and EGR flow. With the ignition key "on" (engine not running) You can backprobe between the black wire (-) and the center wire of the sensor connector with a VOM. While backprobing move the throttle slowly from idle to full throttle and watch the signal voltage. It should be smooth, if it isn't, the sensor is bad.
Hope this helps.
Alvin

[UnexplodedCow]

It's not a big issue, but what about the fuel regulator? It's minor, but it helps. If it's locking things shut, or the return line is plugged, then you'll squirt a lot of fuel into the cylinder. It's a shot in the dark, but it could be. My fuel lines were gross when I got my car. I had to flush/blow them out.

[vdtken1]

I just had the same type of problem. Car was great at idle but would start to stumble as I accelerated. Then it would smooth out for a while and then stumble really hard at highway speeds intermittently almost like the timing jumped. Changed fuel filter and plugs, ignition module but same problem. Finally figured out the diagnostic pigtail was in the diagnostic connector at pin #5 I think. Jumped it to #2 and used an analogue voltmeter to read the service code while running and kept getting 12 & 13 codes. It couldn't sense idle high and low limits. I checked the resistance between the center pin and either outer pin of the throttle sensor found on the left side of the carburetor. As I moved the throttle, sure enough there were flat spots where the resistance would drop to 0 ohms. Another thread mentioned this would tell the computer you were at idle and cut the fuel injector back causing the engine to stall.
Replaced it with one from Pep Boys for about $30. Just 2 screws and a connector and the problems were all gone at any speed.