Idleing Reoblem

[JBronco]

Hey guys im having some troupble with my bronco im gonna tell u all the symptoms and see what u guys got to say about it. I have an 88 with a 351 and out of the blue one day i went to start it up and the fuel pump made a different sound when i turned the key than it usually makes, and it took about 5 secs of turning before it would start. Once it did start it would idle very jumpy jumping from 400-900 rpms and sometimes would cut off on the low spikes. When I drive the truck it is ok only when i stop does it have the problem. Also its odd that if i shut off the engine right after its been running it will start right up however if i let it sit for about 3 mins and try to restart it will take a lot of turning to get her to start. Another symptom is that when idleing puffs of black smoke and some times liquid is comming out exaust and spraying over my garage. All i have done to this point is change the fuel filter and put in some lucas fuel sysytem cleaner and it made no diference. I would assume that the problem was a vacume leak or a TPS problem if it wasnt for the hard to start and the different sound the fuel pump is (the pump sounds kinda like it does when im almost outta gas). Thanks for listening and if anyone has had the same set of symptoms can ya please gimme some input thanks

 

[illinoisbronco]

Hey guys im having some troupble with my bronco im gonna tell u all the symptoms and see what u guys got to say about it. I have an 88 with a 351 and out of the blue one day i went to start it up and the fuel pump made a different sound when i turned the key than it usually makes, and it took about 5 secs of turning before it would start. Once it did start it would idle very jumpy jumping from 400-900 rpms and sometimes would cut off on the low spikes. When I drive the truck it is ok only when i stop does it have the problem. Also its odd that if i shut off the engine right after its been running it will start right up however if i let it sit for about 3 mins and try to restart it will take a lot of turning to get her to start. Another symptom is that when idleing puffs of black smoke and some times liquid is comming out exaust and spraying over my garage. All i have done to this point is change the fuel filter and put in some lucas fuel sysytem cleaner and it made no diference. I would assume that the problem was a vacume leak or a TPS problem if it wasnt for the hard to start and the different sound the fuel pump is (the pump sounds kinda like it does when im almost outta gas). Thanks for listening and if anyone has had the same set of symptoms can ya please gimme some input thanks

pull the codes, correct them , then do a running test so you can find out. you cannot do a running test until you pass the (o) test or you will get a hard fault present code. that should tell you exactly what the problem is or at least point you in the right direction. until you do that, its a guessing game really. a thousand things can make these old trucks do that. if you dont know how to pull a code search it there are lots of brilliant threads on here about how to. then come back with the codes for some more help and direction.

 

[BB33's]

How much gas was in the tank when these problems started? if you were sucking gas off the bottom of a dirty tank your fuel pump can be obstructed. How did the gas that came out your lines and filter look when you replaced it?

 

[JBronco]

How much gas was in the tank when these problems started? if you were sucking gas off the bottom of a dirty tank your fuel pump can be obstructed. How did the gas that came out your lines and filter look when you replaced it?

When the problem started it was at about 1/4 tank and the gas looked fine that came out when changeing filter, one more thing of note is i teporarily helped the nproblem by adjusting the idle up so that it Idles at about 700-800rps it still does bounce around but it doesnt shut off now on the end of the bounce. I really am just looking for some possible problems not really the exact problem i dont know a place that has the Diagnostic tester to get codes for faults /emoticons/[email protected] 2x" width="20" height="20" /> so I am reduced to trying one thing at a time any suggestions would be appriciated.

 

[illinoisbronco]

When the problem started it was at about 1/4 tank and the gas looked fine that came out when changeing filter, one more thing of note is i teporarily helped the nproblem by adjusting the idle up so that it Idles at about 700-800rps it still does bounce around but it doesnt shut off now on the end of the bounce. I really am just looking for some possible problems not really the exact problem i dont know a place that has the Diagnostic tester to get codes for faults /emoticons/[email protected] 2x" width="20" height="20" /> so I am reduced to trying one thing at a time any suggestions would be appriciated.

you dont need a diagnostic tester to pull codes . only a analog multitester and a peice of wire. do a search on pulling codes threads.

 

[miesk5]

Here ya go;

Self Test by BroncoJoe19

Post any Codes found here.

The test may show that all EFI items are good; so, if no EFI related codes pop-up, then check the Fuel Pressure Regulator by pulling the red vacuum line & check for gasoline. If found, the FPR is ng.

Check for Vacuum Leaks

With the engine idling, squirt small amounts of