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Ping Bill S. - Question

Hi Bill,

I have lurked and posted a little from time to time. I think you may be my best bet for providing advice to solve a problem I am having with my 88 Mustang GT Convertible.

I apologize in advance this is going to be rather long and invovled. I will do my best to describe what I have done in a logical manner. If you can find the time to read and reply I would be very thankful.

My 88 Mustang GT Convertible has pinged from the day I bought it used (Note that it is still speed density). This was 3 years ago. The car does not ping until it has warmed up and then it only pings under load and is much worse when the weather is hot (I live in Phoenix Arizona). I knew nothing about cars when I purchased it. Since then I have gained a little knowledge. I bought a code scanner right away. Over the years using the code scanner I have replaced a few sensors per trouble codes the EEC-IV has thrown. My point in telling you this is so that you know that the ECT, ACT and o2s are very new (1-2 years) original Ford parts. Currently I have one code being tripped on my computer (23) which is the TPS sending a signal that is out of range. I recently tested the TPS it is .5v at idle and 4.7v at WOT. I believe the code is being tripped because if you move the pedal too quickly it jumps to 40v then goes back to normal again. Based on my readings of how the EEC-IV works by Charles Probst this should not be effecting my situation but I thought I would throw it in anyway. My timing is set to 10* BTDC (I set base timing by removing the SPOUT connector of course - to save you from asking). I have recently installed a 255lph fuel pump and changed the fuel filter at the same time. Once upon a time (recently) I had a cracked injector so I replaced all 8 with brand new ford racing 19lb injectors. I get 42psi of fuel pressure at idle with the vacuum line disconnected from the FPR. Attempts at running a couple tanks of 91 octane result in no change. Over time my engine started to lose oil pressure (I assume from the pinging). After being fed up along with the major loss of oil pressure and thinking I had carbon deposits causing the pinging I ended up buying a used 5.0 with 60k miles on the clock. It was stock out of a friends car. This engine did not ping when it came out of his car. When I installed it in my car and went for the first drive it started to ping after it warmed up just like my old engine.

I was wondering if you could provide me with some steps to troubleshoot my pinging problem? I am very out of ideas and the one shop it has been to in its time for this problem kept it for a week with no answer in the end.

Regards, Andy

Reply to
Andy Budwill
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I have to ask, first off, did you ever think to replace the TPI, as it is faulty (just the swing in voltage shows you this). Second, have you used a better grade, or different brand of gasoline??????Third, how long have you been using a K&N oiled filter???????

These would be the top items on my list...............

Bill S.

Andy Budwill wrote:

Reply to
Bill S.

When you say TPI do you mean TPI or TPS? I ask because you reference the swing in voltage which I describe happening to the Throttle Position Sensor (TPS). No K&N filter I stick to using STP paper filters. I have gone 4-5 tanks at a time of the highest octane in my area (91) with no difference. I have done 4-5 tanks at a time from Cheveron with no difference, then 4-5 tanks from Diamonshamrock with no difference, 4-5 tanks from Texaco with no difference (all 91 octane).

Andy

Reply to
Andy Budwill

TPS, not TPI...See what happens when I don't get my coffee first..................Did the person before you use a K&N, as oil build up can cause your computer to lean out the engine under throttle..........Finally, you may have a bad knock sensor, which may or may not show up in the codes, but at the same time, can cause a leanout problem as well., which is causing your pinging problems (either that, or your timing is way off)............

Bill S.

Andy Budwill wrote:

Reply to
Bill S.

Well I will throw in a new TPS by the end of the week and see what happens. Not sure if there was ever a k&n on the motor. Remember I don't have a MAF meter which is what the K&N fubars most of the time. Also my particular year is too early to have th knock sensor :( And again timing is 10* BTDC I have had a mechanic verify. A lot of people have suggested perhaps the stock harmonic balancer has spun. I find this unlikely due to the fact my car has been doing this on *two* engines, and the 2nd ran flawlessly from the car it came out of.

Andy

difference. I

Reply to
Andy Budwill

Have we considered that it's an issue with your cars computer. Not only that, but I prefer 12* BTDC. You say you had a mechanic verify this, did he pull the #1 spark plug and make sure that TDC on a compression stroke was indeed were the marks on the balancer lined up to the pointer??? A lot can happen over the years, I would suggest getting this done as well, you migh be surprised at what you find.................

Bill S.

Andy Budwill wrote:

Reply to
Bill S.

I am getting pretty close to yanking the computer and seeing if I can find another 5spd speed density computer to borrow and plug in... What kind of surprise may one find by yanking plug 1 and checking to make sure TDC on a compression stroke lines up with the pointer on the balancer?

Andy

troubleshoot

Reply to
Andy Budwill

Whether or not your timing is correct or not. Lots of things could have happened with your new (actually used) engine before you got it. better to start with the basics and go from there.

Bill S.

Andy Budwill wrote:

Reply to
Bill S.

Since it's so easy to set the timing on these things, why not back it off even further. Since it's pinging on 10 degrees, drop it back to around 8 and see what happens. If the pinging stops, the CEL stays off, the performance is still good, etc, then just run it at 8 degrees (or even less if that makes it work).

When you swapped eng>I am getting pretty close to yanking the computer and seeing if I can find

----------------- Jim '88 LX 5.0 (now in car heaven) '89 LX 5.0 vert '99 GT 35th Anniversery Edition - Silver Mods to date - Relocated trunk release to drivers side, shortened throttle cable.

Reply to
AZGuy

Definitely go ahead an replace the TPS since you're getting a code for that. I've never heard of a false TPS code before. Did you ever pull your distributor before all this started on the original motor? How about the upper intake? The reason I ask is because you could be leaning out due to a vacuum leak. All vacuum hoses in good shape? How much of the new motor did you swap over?

Reply to
Bard

He gave me oil pan to upper intake minus the electronics and distributor... My vacuum lines are in pretty bad shape... I attempted to follow the diagram here

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am unsure what the vacuum check valve is. I should try and hook up withsomeone local who has a 5.0 to see... Andy

Reply to
Andy Budwill

Bet the distributor is off, or our distibutor pick up is going bad.

Bill S.

Andy Budwill wrote:

Reply to
Bill S.

Well I have some more things to go on now I suppose... The distributor was a remanufactured unit from Autozone that I picked up about a year ago. Not sure how much I trust reman'd stuff. Thanks for all the input guys.

Andy

distributor...

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> but am unsure what the vacuum check valve is. I should try and hook upwith

Reply to
Andy Budwill

Let us know what you find when you do the TDC test and replace the distributor...make sure your on a compression stroke.

Bill S.

Andy Budwill wrote:

Reply to
Bill S.

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