1987 ram 250 p/u stalling

[krk418]

hey guys, got a 87 ram 250 with a 5.9 4 barrel. truck starts and runs for 20 seconds then stalls .try to keep it running itll backfire or sputter and stall. starts right back up and does the same thing. checked all vacuum lines , changed fuel filter tune up good, doesnt stall on highway,but will stall when u take your foot off the gas. anyone have the same problem or an idea?

[Stevo2]

Originally Posted by krk418

hey guys, got a 87 ram 250 with a 5.9 4 barrel. truck starts and runs for 20 seconds then stalls .try to keep it running itll backfire or sputter and stall. starts right back up and does the same thing. checked all vacuum lines , changed fuel filter tune up good, doesnt stall on highway,but will stall when u take your foot off the gas. anyone have the same problem or an idea?

Timing issue...maybe a bad timing chain and gears?

[crazys182003]

I would think maybe the fuel pump. If its not pumping out the right pressure it can cause problems. If I rememebr right the PSI should be around 50. I'm just thinking that b/c you said if your on the highway it runs fine. When your running at higher speeds it does generate more pressure so it would end up being correct on the highway.

[sd03ram1500]

i'm thinking if he has a 4 barrel, which means a carb, he should have between 5-7 psi. also, if it a carb, check the fuel bowls. i had a duster do the same thing and found out that the fuel bowls were filling up with rust particles that were not being filtered out like they should be. i replaced the filter too and that didn't help. eventually, i had to drop the tank, totally clean it out, clean out the fuel lines (from all the rust goin thru), and rebuild/clean the carb out. once that was done, it was goood to go.
also, like the other guy said..timing. i had a d150 that would do kinda the same thing (just not real predictable) but i found the timing chain was toast. replaced it and all was much better in the world.