QuestionQUESTION: I have a 1986 e150 with 302 efi engine. It stalls out and backfires(pops)when I try to accelerate.Gets worse under load. I have replaced both fuel pumps and filter. It acts like it is running out of gas. It runs fine when cruising.
ANSWER: Tell me what your fuel pressure and exhaust backpressure readings are at 2500 rpm
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QUESTION: I don't have guages. The shop said that the fuel pressure was 30 something and dropped to 10 at wide open throttle. If it would turn 2500 rpm, I would be set. Can't measure these.
AnswerIf fuel pressure drops that much you have
1 a restricted fuel filter,
2 a bad fuel pump
3 bad wiring to the fuel pump
4 a pinched fuel line
5 a bad fuel regulator
6 a restricted fuel pick up
or 7 a bad fuel pressure tester.
Measure the voltage at the fuel pump connector between the power wire and the ground wire ( should be withing 1 volt of battery voltage. If it is good...
remove fuel filter and test fuel pressure at this point If it is good then the problem is down straem , or if it is bad, the problem is upstream.
