View Full Version : 89 BroncoII w/ 4.0Ltr swap cutting out above 2K

06-07-2011, 03:21 AM
Howdy guys,

My broncoII with a 92 ranger 4.0 swapped in ran great up untill a month ago. It started to cut out on my on the freeway. only two or three bucks and backing off the gas would even it out and all would be well. Its getting worse as time has gone on. It was only in 5th gear first then 4th and tonight it was in 3rd under light acceleration. But not all the time, and the misses are geting longer in durationl. No movement i tach or any other guages.

Fuel pump, hanger and wiring pig tail; plugs, wires, and coil have less than 10k miles, as does MAF, No MAP sensor on vehicle. Oil fiter and fuel filter changed tonight. No change.

Im thinking fuel pressure regulator? Any suggestions would be great. Ive spent the last hour reading 40 pages of postings. Im spent. :dunno:

trail B2
06-07-2011, 12:38 PM
Do 89's have 2 fuel pumps I know 86 and 87 does when one is going out weird things happen.Mine would drive about 7 miles then quite.The high pressure pump would pull fuel and vapor lock without the low pressure.First it cut out under more and more driving situations.

06-07-2011, 01:10 PM
Single in tank fuel pump. Gonna try the Fuel Pressure Regulator.

06-07-2011, 10:05 PM
Fuel Pressure Regulator seems to have solved the problem. Thanks Ya'll