whats up ppl, i'm having a real problem with my truck. i bought it and brought it home and realized it was pinging. Had a friend of the family look at it and he said i needed a new egr vaccumn shut off, got that part and replaced it, the truck ran alot better, still does, but i noticed that is still pings a little bit, like if i push it to the floor doin like 25(in 3rd), it will make like a popping noise maybe 3-5 times before it gets up to a higher speed, is it a ping/miss and i want to know whats making it do that, i have to find out, the timing is at 10 degrees, but i noticed one thing when i was sitting at a light idleing, outta know where it pinged/missed once? does anyone have any thought about this, i want the truck to run clean and strong, any feedback would be awesome, i don't know much but i know some...thank you everyone and have a merry x-mas. :santa:

 

Two things come to mind. Timing or fuel.


Make sure your fuel filters are new. You might even want to connect up a fuel pressure gauge and go around driving and make sure the pressure looks good. At WOT the pressure should be around 40 PSI and hold steady during the duration of acceleration. If it drops then that could be a huge issue.


Check your timing. Make sure your setting it correctly while the spout is out. Try setting it at 8 BTDC. Use 91 or 92 gas and see if the pinging goes away.


Clean your your air filter, Make sure you have no vacume leaks. If you do that is a good source of your problem. Hook a vacume gauge up. Should be around 10-15 PSI at idle.

Check your spark plugs.. Read them. Are they white? black? Smell them. Make sur they are gapped correctly.


Start there.

 

Check the gasket between the upper and lower intake. Spray carb cleaner around the front on both sides. If the engine revs, the gasket is broken. Common problem.

Robbie

 

I have a 91 bronco with a 351 .030 over with a E4od. I have 2 codes 542 which is fuel Pump circuit open ECA to motor ground. The 558 is EGR REgulator (EVR) solenoid circuit failure. Computer is new, and all the sensors are new. At my egr sensor with the koeo i pull a fat 5 volts, and at the egr solenoid thats mounted on the tad/tab bracket i have no juice in that end of the harness. Someone please point me to the bad ground. Engine ground from upper manifold to firewall is tighter the a gnats a..hole. If i pull 2-3* of base timing out it seems to clean up a bit, but i don't want to take anymore out. Im running 10:1 comp flat tops a comp cam #32-255-5 with a 114* lobe sep to compensate for the speed density. New bbk tb twin 61mm. Engine and tranny totally rebuilt. Fuel pressure is @ 42lbs with 19lb injectors.


Thanks for your Assist in Advance

Ford393s

 

Hi. Are you running stock heads on your 351? How is the idle on your truck? Does it surge at all? Roller cam?



I can't help you with the ground issue. At least not from here. The 5 volts is only for refferance. The sensors themselves will return back a certain resistance and that resistance is graphed in the EEC. Some sensors like the EGR sensor will only measure open or close. Most engine sensors themselves will measure resistance and change with hot or cold. Like the air charge temp sensor, coolant temp sensor. What are you running for base timing? Straight 10 degrees, obviously with the spout out?

Next question is. When does it ping? hwy driving? Going up hills? Heavy load?

 

I'm running gt-40 cast slightly opened up, Comp cam .478/.489 no roller, and yes it surges just a tad. Idles ok at start up and kicks down to 700-725rpm. I'll go with the weak signal at the egr sensor..............but the 558 evr code according to haynes tells me if there is no juice at the solenoid pig tail I got a ground/short issue. Just a simple test with a test light with the ignition on it should light up like a Christmas tree, but here I am .....test light in one hand and doo-doo in the other. Yeah I got it set at 10* at baseline. Pings under too heavy a load from a stop. From a roll of about 25 I'll step into it and it'll run good, and the ping starts at about 65-70

 

Your truck could benifit from MAF thats for sure. Almost sounds like your truck is getting to much air and doesn't know how to add fuel because its speed density. I had this problem on my 87' stang when I added throttle body, intake. It wouldn't idle and surged.


My next question is how much horse power you running? With 10:1 compression are you running 91/92 oc gas?


Does your truck when already warm if you restart it does it surge for a bit and then calm down and idle fine?

 

Horsepower never thought of how much just mapped, mocked, and built. Enough to spin those 32's. Nothing less than 90. (ok maybe 89 if I got a hard on to get somewhere, and thats all i can get) Yeah alot of guys have problems with the density thing, bbbut Comp cam ground this one for just that.................. 114* lobe sep. part #35-255-5

It's nothing wild......It just doesn't need MAF..........**** this thing pinged before I rebuilt it so thats why I can say with out a doubt its in the evr solenoid pigtail...just didn't catch the no power harness thing......I hate auto electric. The 93 lightning had gt-40 heads 66cc chambers, and dish pistons that had 13cc's for a total of 79! or 8:7:1 compression.


I guess after 15 years the wiring harness held up pretty well.........it's just all that tape..............ARRRRRRR! Looking for a short cut...........hehehe short cut!