hi i have an 85 ranger 4x4 2.8l. new engine,carberator, computer,egr,02 sensor. and its been in the shop at least 15 times this year. manual trans.

it idles good. runs smooth. but when im driving it pings till i almost max rpms for each gear. im lookin at the vacuum to the egr for blame. but i dont know whats controls the vacuum to it, nor do i know when its supposed to have vacuum. im totaly stumped. please help me out if you can. thanx

 

Several things can cause pinging:
1. Low octane fuel or bad fuel (try a tank of higher octane)
2. Timing not correct (usually the culprit)
3. Carb adjusted wrong
4. Bad or wrong plugs
5. Points, rotor, or cap
6. Vacuum leak

Those are the easy things to check. If all of those are OK, then you might have electrical, emission, or fuel problems.

 

My '95 3.0 and my '99 3.0 both started pinging. I moved up to 89 octane for both vehicles and the pinging stopped. When I change plugs and wires I'll move back to 87 octane to see if that will cure the pinging.

 

For your consideration: I don't think new wires and plugs will help. The pinging comes from carbon deposits that have formed on the valves and piston in the combustion chambers when dino oil is burned incompletely and also when fuel is not in the best condition. Many engines, as they age, drift up in their octane requirements as these deposits grow. The deposits set off the fuel mixture before the engine is ready.

Removing these deposits is a tricky process. There's lots of fuel additives on the market and it's difficult to know which one will do a proper job. Some may not work at all and others are so "effective" that large chunks of deposits may be displaced which can cause engine damage. My suggestion is Ethos FR which I have been using for some time to avoid this problem in the first place. With just over 1000 miles on my engine, I have "hard evidence" that it will work but I like a more gradual process of removing these deposits that this product will produce. Several companies, notably a company that operates garbage trucks for San Diego, CA have posted their experiences with Ethos FR which seems a more substantial testimonial than those from individuals. Because this product seems to offer more than one advantage, I think it is worth investigation. In a few thousand miles, it should be possible to use regular once again.

The oil I use, SynLube, is designed to take advantage of the fact that any engine will eventually burn some of any oil. This formula includes synthetic moly and graphite which will, over many 1000's of miles, leave a thin deposit layer over valves and pistons making if almost impossible for carbon deposits to take hold. It also burns at about 20% of the rate of petroleums.

 

thanx alot for the tips yall!!!!

my engine has 2400 miles on it. so i dont think its the deposit problem. my timing is set perfect. have new plugs and wires. and have replaced all possibal sensors that could couse pinging if faulty. so i guess i could have a vacuum leak somewhere.

it only pings after the engine is at full operating temp.
ive got stp octain booster in the tank right now and it still pings.
its very frustrating after having spent over $3800 tryin to get this thing running right . maybe my egr isnt getting vacuum. ive read that if an egr doesnt open when its supposed to. it could couse ping. im tryin to figure out how to trouble shoot my vacuum system with it having soloniod valves and all.

anyone ever done this? am i barking up the right tree maybe?

 

Vacuum guages are cheap and will tell you a lot of information in a short time. If you don't have one-go get one. It is a great troubleshooting tool.

 

2400 miles on an '85 Ranger sounds like a rebuilt engine to me. You should still have some kind of warranty after just 2400 miles.

 

Hey rickjr, I'd like to elaborate a little on what hreed has told you. These engines do have knock sensors. The timing is 100% electronic control (no vacuum advance, no centrifugal advance). First of all, you are correct about the EGR ... insufficient (or zero) EGR flow will result in increased pinging. But about the timing ... one thing that I've noticed is that these knock sensors tend to "over-compensate". So, you would experience the exact opposite symptom from one of these engines than what you would experience from an older engine with NO KNOCK SENSOR. Here's what I did with mine ... it was pinging on 87 octane gas. If I put a very high octane fuel in it, and the pinging disappeared, it was because the distributor was advanced just a tad bit too far for the electronics to compensate for. However, if the 93 octance DID NOT DECREASE THE PINGING AT ALL, then it was because the knock sensor was over-compensating, and advancing the ignition so far that it pinged on the very highest octane gas. The solution is to REDUCE the octane. Yeah, I know, sounds stupid. You will see references in some older threads to the use of Marvel Mystery Oil, and the like. If you use 87 octane gas, and add MMO to it, you've basically reduced the octane rating to 86.5 or 86. The knock sensor will perceive this at the very first hint of a ping, and delay the timing enough to STOP THE PINGING. Besides the STP octane booster, have you tried different octanes of gas?? As mentioned about the EGR, don't let that slide. Do indeed check the vacuum. There is a solenoid valve on the passenger side of your inner fender wall, that turns the vacuum signal on and off. I believe the vacuum signal should come on at part throttle, but check with a manual or someone who is expert first. If you check your vacuum, and it is coming on when it should, THEN, you can check the valve itself. If you hook up a hand-held vacuum pump (similar to what hreed referred to ... it has a gage on it), and you pull a strong vacuum on the EGR valve at idle, the large flow of EGR at idle should make the engine idle VERY POORLY, maybe even stall out. If it does do this, then your EGR valve is functioning (not saying it is working PERFECTLY, but at least it is working). If NO CHANGE IN IDLE AT ALL, then the valve is not working at all.

I'm really curious about your problem. Please keep us posted.

 

hey houkster. yea its remanufactured and has a 3 year or 50,000 mile warranty. but unfortunatly it only covers the engine its self. not all the pre exsisting componants that make it run good or bad.


thanks hreed i thing ill run up and find me a vacuum gauge. and find out how to trouble shoot my truck with it. i guess ill disconect the hose from the egr valve, connect it to the vacuum guage, and goose the throttle at the carb. we'll se what happens


hello amp17757.thanks for the large amount of info on the truck. sounds like you know ranger v6's pretty well .

ive allready replaced my egr valve. it seems i did it prematurely. cuz it made no differance what so ever with engine performance.
when i had it in the shop last. they hooked it up to a diagnostec computer and it read an egr code. and a carburator sensore code. what ever that part is called, that links the carberator to the EEC IV. computer. " 5 days old i might add". but the tech thinks that it got a faulty reading about the carb senser do to human error at the throttle during the test.

i hav'nt tried differant octains of gas yet. it didnt accure to me untill i found this forum and met the friendly helpfull people in here such as yall who replyed. thanks again


i heard from one source a young parts store emplyee that if a knock sensor is bad. the engine will stop running when its warmed up. is this true or false? can it couse the pinging if its bad? it probly would have shown when the eec was hooked up at the shop huh. oh! does the MMO have instructions for adding to gas? i might try that

 

I own an '85 2.8, except mine's a 2WD auto. I've experienced a few of the things that seem to be common with these engines.

About the MMO - Yes, it does tell you on the can what ratio to use in the gas.

About the KNOCK SENSOR - A malfunctioning sensor can definitely cause pinging. As far as the engine not running at all, I can see where that could happen. Since these ignitions depend HEAVILY on input from the knock sensor (timing completely electronic, no vacuum advance, no centrifugal advance), it would be possible for the timing to drop WAY BACK (dramatically delayed/retarded). I don't know how far back they are electronically capable of dropping, but if your timing were to get all the way back to 5 or 6 degrees AFTER TDC, the truck would run like crap, IF AT ALL. One of the frustrating things is that the SENSOR could malfunction, OR, the COMPUTER could be malfunctioning, or ANYTHING IN BETWEEN. Electronics are great when they work, but when they fail, they're horrible! I personally have plans to replace my ignition system COMPLETELY with a DUI (Davis Unified Ignition). It DOES have vacuum and centrifugal advance (no electronics), AND, it is HEI, with the spark coil ON THE DISTRIBUTOR! It is ONE UNIT that replaces the entire ignition system. Of course, since it does have vacuum advance, I will need to install a carb with a vacuum advance port, or "rig up" some other means of vacuum. If you continue to have NO SUCCESS with this problem, I would strongly suggest considering an alternative ignition system. Many in this forum have gone the way of the older Pinto V6 systems (1978?? 1979??). Any of the number of alternatives available will curtail the knock sensor & electronics woes.

Keep us posted.

 

well i got it to stop pinging with premium unleaded. the exsoust smells rich. and when i hit the gas after sitting at a stop. it blows smoke out the back end. so.........? does the differant gas affecting the pinging tell us anything as far as narrowing down the list of possibal problems? the only other thing i changed besides the gas is the air charge sensor. wich didnt seem to affect anything.

 

Hey rickjr, when it blows smoke, is it blue, dark gray, or black?? Something else just came to mind that never even occurred to me before ... that carb has an electrical connector on the back of it. The computer plays some part in controlling the fuel mixture via that plug. I've never had my carb FULLY DISASSEMBLED, so not sure exactly what the internal workings are. But, when I first got my Ranger, it was PLAGUED with stalling out every time we rolled up to a stop. After lots of messing around, one of the things that was most effective was to simply PULL THAT CONNECTOR OFF THE CARB. The carb seems to run in a default mode, which is a bit rich, but it runs good. So now I'm wondering if YOUR problem has anything to do with that circuit??? If your truck is blowing dark gray or black smoke, it's obviously way too rich. So, if the opposite problem had been occurring before (too lean, causing lean spark knock)??? You also might be suffering from a disease which I am CONSTANTLY PLAGUED WITH!! That would be ... 2 or more things going wrong AT THE SAME TIME, causing conflicting and confusing symptoms. But, since it's easy and free, just try disconnecting that plug from the back of your carb once, and see if ANYTHING changes.

At the risk of sounding really stupid, what is an Air Charge Sensor?? [O2 sensor maybe???]

 

yes i have unplugged the computer from the carb recently. when i was running regular gas and the pinging was redused. but the truck lost power. and i do from time to time have problems with the truck stalling when i come to a stop. my throttle position solonoid hasnt worked since i got the truck 4 years ago. i bought a new one and it still dont work. mechanics are confused about that one. when it blows the smoke i cant realy tell if its grey or blue. it only does it after sitting at an idle for a few minutes. i hope its not blue cuz the engine only has 3200 miles on it..........oh yea back to unplugging the comp from the carb. after i replaced the o2 sensor it doesnt affect the enginse power as far as losing it. but it seems to run richer

 

oh air charge sensor is the one located in the air filter housing. it reads the air temp going into the carborater