As soon as the engine is warm, the engine looses power?

Tiny
CJAMCEKS4
  • MEMBER
  • 1993 FORD ESCORT
  • 4 CYL
  • FWD
  • MANUAL
  • 155,000 MILES
93 1.9L manual Ford Escort. 155,000 miles. Timing belt and water pump changed 5,000 miles ago. As soon as the engine is warm, the engine looses power. New plugs and wires. Catalytic convert checks good. Fuel injection system checks good. Fuel pump and filter changed. Mass flow sensor changed. Ignition control module changed. Problem still exists. Are there any suggestions.
Friday, July 1st, 2011 AT 9:20 PM

26 Replies

Tiny
RASMATAZ
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Here are some additional areas to consider:

Exhaust Gas Recirculation (EGR) System:

Air/Fuel Ratio:

Throttle Position Sensor (TPS):

Idle Air Control (IAC) Valve:
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Friday, July 1st, 2011 AT 9:35 PM
Tiny
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Perform a compression test. Each cylinder should around 150 PSI +/- 10-15 PSI, and max difference between high and low should be no more than 15 PSI.
Get the engine warm and check the fuel pressure at the fuel rail/pressure regulator.
Check the output of the coil when the engine is hot, it should be bright blue.
Run a bottle of fuel system cleaner through the tank.
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Friday, July 1st, 2011 AT 9:46 PM
Tiny
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That, too.
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Friday, July 1st, 2011 AT 9:46 PM
Tiny
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Compression test was good. All cylinders read 160 with no difference. Fuel pressure drops when engine is warm. This is why the pump, filter and ignition control module were changed. Coil changed with plugs and wires. If engine runs well for 20 minutes, could timing still be off?
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Friday, July 1st, 2011 AT 10:23 PM
Tiny
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Check if the injectors and fuel pressure regulator are leaking this will drop the fuel pressure.
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Friday, July 1st, 2011 AT 10:26 PM
Tiny
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Since it seems to be fuel related, fuel pressure regulator? Would it fail only at normal operating temperature
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Friday, July 1st, 2011 AT 10:52 PM
Tiny
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Injectors tested good.
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Friday, July 1st, 2011 AT 10:52 PM
Tiny
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Check the FPR and could also be the fuel pump check valve-
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Friday, July 1st, 2011 AT 10:54 PM
Tiny
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What is the fuel pressure when cold and hot? It sounds a bit like vapor lock.
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Friday, July 1st, 2011 AT 11:17 PM
Tiny
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Timing isn't adjustable. It is a function of the timing belt cover and making sure marks are in the right position. If it slipped one tooth would it run right at low engine temperatures and not when the engine is warm?
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Friday, July 1st, 2011 AT 11:53 PM
Tiny
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The valve timing is the relationship between the camshaft and crankshaft positioning make sure its not 180deg off-Verify it and then come back
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Saturday, July 2nd, 2011 AT 2:27 AM
Tiny
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Ignition timing is set by loosening and rotating the distributor. And yes, if the ignition timing is off, it can run fine when cold, since the computer is in cold start mode. And then once the engine warms up, if the timing is not correct, it can cause issues. Does it make any noises while accelerating when hot?
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Saturday, July 2nd, 2011 AT 4:22 AM
Tiny
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Engine sounds great when it starts and runs for first 15 minutes. It makes no noises when accelerating when hot. I don't think a 4 cylinder would run well cold 180 degrees out. This car does not have a distributor.
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Saturday, July 2nd, 2011 AT 1:29 PM
Tiny
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You have not answered anything about fuel pressure -maybe the fuel pump behaves during the 15mins then goes haywire when it heats up-Check and monitor the fuel pressure and get back with the readings before we can continue.

BTW we both know it doesn't have a distributor
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Saturday, July 2nd, 2011 AT 2:10 PM
Tiny
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The 93 Escort LX had a distributor. So if this one doesn't, it's had an engine change. As far as I recall, DIS wasn't introduced for this model until 95 or 96.
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Saturday, July 2nd, 2011 AT 4:48 PM
Tiny
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No. This is the 3rd 93 escort I've had and none have had a distributor cap. All use an ignition coil. If there is a distributor cap, I've never seen one.
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+1
Saturday, July 2nd, 2011 AT 4:59 PM
Tiny
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According to the mechanic, fuel pressure drops when engine gets warm but at this point I'm not sure if I believe him.
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Saturday, July 2nd, 2011 AT 5:01 PM
Tiny
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And there have been 3 fuel pumps installed. I did the first one. The garage has done 2 more, claiming the first one they installed went bad in 25 miles.
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Saturday, July 2nd, 2011 AT 5:53 PM
Tiny
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A DIS system don't have a dizzy cap its a direct ignition system

Hook-up a fuel pressure tester to the fuel test port and monitor the pressure to confirm that the FP is doing its job-An EFI system has to have the correct pressure to function accordingly
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Saturday, July 2nd, 2011 AT 10:36 PM
Tiny
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Yeah, I know. I just didn't think that Ford had DIS systems that early, especially in the Escort. My 98 Escort had a distributor, while my 99 didn't. My 95 Contour was DIS, while my 93, 94 and 89 Tauruses all had distributors.
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Sunday, July 3rd, 2011 AT 3:01 AM

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