Fuel injector replacement issues
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Fuel injector replacement issues
I am looking for information, advice, suggestions.
I am considering the purchase of new fuel injectors for my 1987 F-150 4x4 w/4.9l six, 160K miles (only 50K on long block), totally stock except for Jacobs ignition. I have been fighting the "dreaded stumble" for some time (I am aware of the EGR restrictor plate trick) and know that some have had success overcoming it with new injectors. I am also unhappy with my fuel mileage (10-15 mpg, mostly near the lower end of the range) and am thinking new injectors might improve it. Other than the stumble and mileage, truck runs pretty good.
I know from other threads that the correct stock injector size for my application is 14-lb. I found a source of Bosch 15-lb injectors for a reasonable price. I would like to know what issues I will face if I decide to go with these larger injectors (I am not planning on any performance upgrades in conjunction with the new injectors). Is the difference between the two negligible for this application? I most certainly don't want to decrease what I consider already poor fuel mileage.
Thanks to any and all for your input.
I am considering the purchase of new fuel injectors for my 1987 F-150 4x4 w/4.9l six, 160K miles (only 50K on long block), totally stock except for Jacobs ignition. I have been fighting the "dreaded stumble" for some time (I am aware of the EGR restrictor plate trick) and know that some have had success overcoming it with new injectors. I am also unhappy with my fuel mileage (10-15 mpg, mostly near the lower end of the range) and am thinking new injectors might improve it. Other than the stumble and mileage, truck runs pretty good.
I know from other threads that the correct stock injector size for my application is 14-lb. I found a source of Bosch 15-lb injectors for a reasonable price. I would like to know what issues I will face if I decide to go with these larger injectors (I am not planning on any performance upgrades in conjunction with the new injectors). Is the difference between the two negligible for this application? I most certainly don't want to decrease what I consider already poor fuel mileage.
Thanks to any and all for your input.
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Joined: Mar 2005
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I had the same problem as you, it's pretty much hit and miss with what causes it but what I did find was the TB gasket was sucked in and the EGR valve was toast along with the EGR position sensor, now it's all good. No codes, no nothing.
As for the injectors, I bought a set of used but good mustang 19#ers and they work well. It did kill my mileage a little since the computer is cal'd for 14's. I also have a bunch of mods to my 4.9 though. (a bunch of them were very inexpensive) It may affect yours different by going to 19's but you would be good with 15's I'm sure.
As for the injectors, I bought a set of used but good mustang 19#ers and they work well. It did kill my mileage a little since the computer is cal'd for 14's. I also have a bunch of mods to my 4.9 though. (a bunch of them were very inexpensive) It may affect yours different by going to 19's but you would be good with 15's I'm sure.
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Joined: May 2002
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From: Broken Arrow, OK
Those 15's might actually be 14's. There are two different ways to rate an injector. The most common is to rate them a 3 bars, which is 43.5 PSI. The other way rates them a few PSI above or below that, but I don't remember which. It would be just enough to make a 14 flow like a 15 or vice versa. In this case it really doesn't matter, the two are close enough that the PCM can compensate for a little extra fuel. I'm a little leary about Bosch injectors. I've had some bad luck with them in the past. Check out this place before you spend the money.
Before spending money on new injectors, why don't you have the stock ones professionally cleaned and see if it helps first.
Before spending money on new injectors, why don't you have the stock ones professionally cleaned and see if it helps first.
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Thanks for the replies so far guys.
I thought about having the injectors cleaned, maybe more info from knowledgeable users will help. First and foremost, I live in Alaska, which means 1) my truck will be down for the time it takes to ship them out and have them cleaned; 2) shipping by FedEx or UPS to/from Alaska is mostly ridiculous, making the cost/benefit ration rather questionable; and 3) the 15's I found sell for around $28/ea new.
I've also seen that it may be possible to perform "do-it-yourself" cleaning, but it doesn't appear that you could do nearly the job the pro's do - comments?
One question about cleaning: from what I read, it seems that the internal springs are not replaced during this process. I made the assumption that those springs might be weakened after extended use, and that the cleaning process might help fuel flow but can't rejuvenate fatigue in the springs - true?
I thought about having the injectors cleaned, maybe more info from knowledgeable users will help. First and foremost, I live in Alaska, which means 1) my truck will be down for the time it takes to ship them out and have them cleaned; 2) shipping by FedEx or UPS to/from Alaska is mostly ridiculous, making the cost/benefit ration rather questionable; and 3) the 15's I found sell for around $28/ea new.
I've also seen that it may be possible to perform "do-it-yourself" cleaning, but it doesn't appear that you could do nearly the job the pro's do - comments?
One question about cleaning: from what I read, it seems that the internal springs are not replaced during this process. I made the assumption that those springs might be weakened after extended use, and that the cleaning process might help fuel flow but can't rejuvenate fatigue in the springs - true?
