Engine sputter and poping noise

[slow91fj90]

Ok so I got the Bronco running and went for a drive. Everything felt good for about 2 miles or when it warms up. When I came to a stop and went to drive away in first it sounded like it back fired in the intake tube for a second, then drove fine. About a mile later it while driving about 45-50 it started sputtering like it was out of gas for about 30 seconds, then back to normal. Here is some info on the truck 5.0 fuel injected explorer motor, brand new, every sensor is new and using a RJM harness. Im not currently using a VSS. Anyone have any ideas? Does this sound like a vacuum leak? Timing is set at 10 degrees.

Thanks

 

[BobbyA]

Not to jack the thread but I am in similar boat. Any responses would be greatful.


Just finished my efi swap and trying to tune it a little and it is back firing through the TB. Could that just be a timing issue or the valves not adjusted right.

i did put new heads on and new cam, lower end is still stock 302 from 71 with about 79,000 miles on it. What do you guys think?

 

[Viperwolf1]

Ok so I got the Bronco running and went for a drive. Everything felt good for about 2 miles or when it warms up. When I came to a stop and went to drive away in first it sounded like it back fired in the intake tube for a second, then drove fine. About a mile later it while driving about 45-50 it started sputtering like it was out of gas for about 30 seconds, then back to normal. Here is some info on the truck 5.0 fuel injected explorer motor, brand new, every sensor is new and using a RJM harness. Im not currently using a VSS. Anyone have any ideas? Does this sound like a vacuum leak? Timing is set at 10 degrees.

Thanks

Sounds more like a fuel issue to me. Check fuel pressure. A vacuum leak wouldn't come and go.

 

[mudslut]

Not to jack the thread but I am in similar boat. Any responses would be greatful.


Just finished my efi swap and trying to tune it a little and it is back firing through the TB. Could that just be a timing issue or the valves not adjusted right.

i did put new heads on and new cam, lower end is still stock 302 from 71 with about 79,000 miles on it. What do you guys think?


stock cam or did you upgrade to a stage 2 or 3 for instance

 

[jw0747]

Sounds more like a fuel issue to me. Check fuel pressure. A vacuum leak wouldn't come and go.

x2. do you have a fuel pressure gauge in your system? check fuel flow from tank forward to engine. are you operating with 2 fuel pumps? if you're operating with a single HP fuel pump only that might be your problem because if flow from tank to pump is tight fuel pump can cause problems. also check fuel filters.