Engine Pinging

[earnedit3]

Hi, newbie here. I’ve seen a lot of EricTheCarGuy on youtube, so joined the website just now. Anyhoo..
1995 Ford F150, 154k, 302 V8

Topic

[dreamer2355]

Im not buying the issue with the fuel injectors. Did the technician do a injector leak down test? What evidence did he/she show you they were bad? Did he show you a scope pattern?

I am happy the pinging has gone though.

Keep us posted!

[johnzcarz]

What kind of injector cleaning was done? If it involved pouring a bottle of stuff in the gas tank then IMO the injectors were not cleaned. If it were me, before spending the $ to replace 8 injectors, I’d seek out a shop that does an injector cleaning service where they disable the fuel pump and run the cleaner right into the fuel rail – they actually run the engine using only the cleaning solution.

[dreamer2355]

Quoted From earnedit3:

Thanks for the response, Dreamer and Johnz. No injector leak down test or cleaning; he based his worn injectors on the shuddering starts when cold, and the computers rich condition because the injectors are not spraying like they should, and the mileage. Any thoughts?

Like i stated earlier, there is no evidence at all the injectors are at fault.

This technician needs to use an oscilloscope to check for the injector wave forms to prove there is an issue.

I also like the suggestion of the injection cleaning too made earlier.

Eric has a video on this –

http://www.youtube.com/user/EricTheCarG … izKtru7RcU

However, looking at scan tool data will show you if the vehicle is trying to add or take away fuel as well as showing you any type of misfire issues, thats on the assumption he/she knows how to interpret that information.

Keep us posted.

[EricTheCarGuy]

OK I know you checked the ignition timing but what about for slack in the timing chain as I suggested in my last post? If the engine has a mechanical issue with timing doing anything else at this point is a waste of time till you get the engine running properly. The check takes about 5 min to do and can save you a lot of headache and money you would have used on buying injectors. BTW your reasoning for buying injectors is I believe ‘misguided’ due to the fact that you never checked them, replacing parts is really not part of a diagnosis unless all other possibilities have been exhausted. It just so happens that someone sent me a great video on injector testing that might help you determine if they really are a problem or not but first check for that timing chain slack because as I said anything else would be a waste of time if you have too much slack in the timing chain.
http://www.youtube.com/watch?feature=pl … hUrMdzODYU

[earnedit3]

Hey Eric and dreamer, the timing chain was checked a year ago, as a mechanic friend and I replaced the water pump and front plate, as it was cracked, and checked the chain. It looked to be almost new, as if it had been replaced at some point before my purchasing the truck in 2006, and had very little slack. Also, I pointed out to him that I had done the seafoam treatment, Marvey Mystery Oil, and LucasOil Deepclean, with no real change.

[Matt]

I would still do the ‘slack test’ as Eric suggested. Timing chains shouldn’t really look bad unless they are really bad i.e. gears are missing teeth and the chain is ground up.

[EricTheCarGuy]

It only takes 5 min to check and then you would KNOW it’s not an issue. Diagnosis is a process of elimination and it’s good to stick with the basics first especially when it comes to engine mechanical as it’s often overlooked until a bunch of electronic parts have been replaces with no result.

[Author]

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