dave1123

First of all, my WJ 4.0 is currently running perfectly and getting me normal to good fuel mileage, however I've just noticed 2 of the injectors have cracked outer casings. I'm assuming this exposes the solenoid coils to weather and garbage. Do you recommend replacing all of them? Jeep has 195K miles on it. What do you recommend for brands? Rockauto has Standard Motor Products new for $35 each. I've heard Bosch is better? Bosch PN 0280155917 EV6? Where can I get them?

dave1123

As a followup, the OE injectors are Siemens which are known to go bad, according to what I've read.

andrewmp6

I have done both over the years replaced a bad one or two and replaced them all.If money is tight replace the bad ones if you got it i would do them all since im already there.On the Bosch ones have you tried ebay and amazon ?

dave1123

I've looked on them but most seem to be for Mustang and not that PN. I went to the Bosch website and the ones I mentioned are what they recommend, but I can't order or buy them from the website. I'm reluctant to buy rebuilt because, to me, it's like buying a used carbuerater. I found a list of Ford V6s that have ones that fit, but I'm not going to prowl junkyards looking at Fords because I don't know what I'm looking at. These are for a WJ which are longer than the ones in ZJs or XJs.

SteveMongr

The first link may be what you are after, otherwise the second link is Precision Injectors;
http://www.ebay.com/itm/Jeep-99-06-4...5XQFv-&vxp=mtr

https://precisionautoinjectors.com/c...jeep-injectors

dave1123

Thanks Steve! I just ordered from Precision Auto Injectors. Thanks for doing the legwork.

97grand4.0

How did you make out on this?

dave1123

I just put them in this morning and already I can feel the difference. Before the idle would drift about 50 rpm either side of 700, but now is steady as a rock around 725. Throttle response is quick and clean and I can tell by the vibrations in the steering wheel that it's running smoother. I just zeroed the average fuel mileage on the overhead console and we'll see tonight if there is any change. The one injector that was cracked had carbon on the nozzle end so I'm not sure if that was spraying right. They are the original Siemens but are 2 different part numbers.

97grand4.0

Having done nothing to mine ever except the bottle and battery and seafoam thing, I am wondering if it would be worth the performance difference.

dave1123

If you want my opinion based on only 5 hours running on them, do it. I've learned over the years that when you change anything from stock, you run a risk of having problems. Being that this jeep is my only transportation and necessary for my paycheck, I was reluctant to do this, BUT with one cracked and 196K on it, I didn't have much it lose. This old bastard feels like a new engine now. On the fuel mileage, I'll know better after doing my newspaper route tonight. I've been averaging 15.7 mpg between my route and my other driving before. It helps that I don't have to sit and idle it to stay warm now because it's been around 12.3 over the winter and 10.7 when it was REALLY cold. Last summer, I took a trip to Rochester at 70 mph in 90* heat with all the windows down and got 27.2 actual by measured fill-up. That trip was all flat terrain with a moderate wind and a 2-way average. For those who don't know, that's thru Montezuma Swamp National Wildlife Refuge.

dave1123

Okay it's still hard to tell if there is any difference because I've only burned 1/2 a tank since the change and my average over that period is still 15 and change. I will say that I noticed I have to use less throttle to get it moving from a stop and the trans seems to shift smoother at low speeds. I think I'll have to do a full tank burn and a pump-measured fill-up to really know.

jhc7399

Dang, wish I had seen this. I have 3 or 4 sets of 917's that I can't move, rebuilt and tested that I could have given you for half that cost.

I run the 917's in my 99 and love them. No one buys them though because they are not 784's or 703's?

dave1123

Well, I couldn't tell you what these are because they're already in, but the advertisement said "various part numbers" but were supposed to be Gen 3, EV6, 4-hole reman Bosch injectors. The numbers were printed in black ink and were faded anyway. I've noticed about 3 mpg better average fuel mileage than I did. You can't really tell much because of the conditions under which use my jeep. I deliver newspapers so I stop at a mailbox, start up again and stop within 50 to 100 feet continually 250 times every delivery night, 3 times a week. There are short bursts where I might go 1/2 mile or so, but usually not faster than 30-40 mph.

jon-d

what are the differences between the 784's, 703's 917's? I am looking to replace the stock injectors on mine with the 4 hole type.

JY95ZJ

Sorry Dave not trying to hijack your thread, but I have the same question about injectors except i have the 5.2 motor. I was just curious what would be the best for this motor,my gas mileage isn't bad for a v8 it says I'm at 15.9mpg but if I can get it down a little it wouldn't hurt my feelings. Mainly looking for better throttle response. I'm no stranger to the junkyard so wouldn't be a problem for me to pick some up there but all info is appreciated.