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View Full Version : Predonation Noises and Diagnostic Steps



Breadfan
06-25-2013, 07:18 PM
Hey All!

My Marauder is doing pretty well, it is no longer my sole daily driver, so it gets some rest time. A week ago I took it out on a Saturday to a family event, about a 100 miles round trip. I gassed up about 10 miles into that trip, at a Shell station I've used plenty of other times with no issues.

Anyway, a few miles from home, I heard a "ticking" type noise, that seemed like very quiet pinging. It only happened when in gear - so I thought at first it was the trans.

I've let it sit since, but took time today to check it out further. It sure sounds like pinging. It seems to only happen with some load, i.e. in gear. I can hear it when moving/lightly accelerating, or when stopped, holding the brake and giving it a bit of gas.

Obviously I am not driving it, but did some very short diagnostic moves today.


The ping is light right off idle, and comes back when there is a load. With no load (in park, idling or revving) there is no noticeable ping.

I'm still running my stock Trilogy kit, but I have the stock Trilogy tune in 93 and 91 octane versions. I run the 91 tune all the time, just to be safe incase I get not-so-great 93.

I did hear a slight bit of pining one fill up at a WaWa, which I noticed had 92 octane. (I decided to try it after seeing a guy routinely filling up a red Ford GT there!) I never went back after that.

Soooooooooo...

I'm thinking at 91k miles, with 65k of that sc'ed, with a Kenne Bell boost a pump, I may be in need of some service.

My diagnostic steps will be:

1.) Fuel filter - though it shouldn't have too many miles on it, the non-daily driver spot my MM is in means that it's been some time since I've done it. It's due, and could be the culprit. (I still have the stock filter lines/elbows btw)

2.) Fuel Pressure Check - I should have an actron fuel pressure gauge bumming around somewhere in the garage, will locate and hookup and get some fp readings. What should fp be at stock? How about say, 2000rpm? Any diagnostic tips?

3.) Fuel Pump - it's possible my stock fuel pump is getting worn out, and not able to push the fuel. I would prefer to upgrade to a GT40 pump if I swap out. Are there install guides for doing a fuel pump swap, and can I do this swap to a GT40 pump with the stock Trilogy KB boost a pump? (Noting I'm at the stock 3.4 pulley and tune) Also - should be plug and play otherwise, i.e. my current tune will work (even if it can be improved upon)

4.) KB Boost a pump - I doubt this unit is the culprit. But - do they ever fail? How can you check them? But - since I ping right off idle, I don't think it's any matter. It should only amplify the fuel pump when the boost switch activates it, right?

5.) Bad Gas - in the car - An option, but I'm not thinking so. I think it had about 40% remaining in the tank when I filled up, and then I drove 90 miles, only noticing the pinging in the last 2-3 miles. I figured it would be more noticeable earlier on.

Anyway - as you can tell, I gave this alot of thought - after taking a look at it tonight, I went to one of the 2 places guys think most - the lawn mower in this case.

;)

Thx!

Breadfan
06-26-2013, 06:18 AM
Are the Ford GT pumps up in price? I recall they were $80-$100 but now I see $200...is this a valid price?

I may pick one up, regardless if the fix I think its time for a small fp upgrade as my stock pump is 10 years old with 91k behind a BAP

Oh...and anyone run it ok with the stock Trilogy BAP - the 20amp'er...


If I do need a pump, I can get a good price on a stock setup (Motorcraft PFS205), have the setup that has worked perfect for my tune and setup with the BAP I have, and comfortably plan a more intricate upgrade later...maybe the best bet for me now.