Just replaced four 02 sensors truck does start a little easier and it sounds better but it still idles rough, dies and there is backfiring through the carb. Trying to figure out what else might be wrong with this thing? Anyone got any advice?
96 disco rough idle and engine dieing
- Thread starter Benny1
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
- Joined
- Jun 28, 2004
- Posts
- 10,473
- Reaction score
- 181
I am sure you had another post, but mileage and last major tune up? Fuel pressure has been tested? Fuel filter changed?
Hey joey mileage is 113,000 Not sure on tune up but my mechanic freind and I are going to do a tune up after we fix anything that needs repair. It is blowing a real dark smoke out of the exhaust until it gets started good and warmed up then the engine seems to run a little smoother though it still dies if I stop and let completely off the gas Then it starts real hard and gets warmed up little by little. It wont idle in park and dies if I'm not constantly giving it a least a little gas. The only way to really keep it running even after it is warmed up is to throw it in neutral when I stop and give it a little gas until I can go again. We replaced all four of the 02s this morning and there is obviously something else wrong with it and until my freind is able to borrow a computer scanner to check the ecu for additional problems we dont know what the deal is? Any ideas from the problems I'm describing? Hey thanx for the response and so you know I bought this truck with all these problems already and thats why I don know when it had its last tune up!
- Joined
- Jun 28, 2004
- Posts
- 10,473
- Reaction score
- 181
I would start with a full tune up, check fuel pressure and change fuel filter.
If I were to guess from what you are saying, I would say injectors maybe bad, but can say for sure with out a leak down pressure test.
If I were to guess from what you are saying, I would say injectors maybe bad, but can say for sure with out a leak down pressure test.
You might check your injectors for leakage by depressing the test valve on the pass side fuel rail after your truck has been sitting for a few minutes
It looks like a tire valve - have a rag handy in case fuel squirts out.
I'd check it after 5 mins, if it still has press, then turn the key on for 30sec. - wait 20 mins and check again.
If it still has pressure after 20 -- 30 mins, I doubt the problem is the injectors leaking.
I used a tire gauge to check fuel pressure @ idle, (have rag handy), if you're under 30psi, I'd also consider a fuel pump (after you change fuel filter)
If the absence of o2's on your truck (didn't you say it had bolts in it?), got your ECU all whacked, it may take several drive cycles to remap. (If it's fixable).
In the meantime, I'd tune it as Joey said, plugs,wires, air & fuel filters - and put premium fuel in it.
There's other possibilities, but those can come after all this.
luck,greg
It looks like a tire valve - have a rag handy in case fuel squirts out.
I'd check it after 5 mins, if it still has press, then turn the key on for 30sec. - wait 20 mins and check again.
If it still has pressure after 20 -- 30 mins, I doubt the problem is the injectors leaking.
I used a tire gauge to check fuel pressure @ idle, (have rag handy), if you're under 30psi, I'd also consider a fuel pump (after you change fuel filter)
If the absence of o2's on your truck (didn't you say it had bolts in it?), got your ECU all whacked, it may take several drive cycles to remap. (If it's fixable).
In the meantime, I'd tune it as Joey said, plugs,wires, air & fuel filters - and put premium fuel in it.
There's other possibilities, but those can come after all this.
luck,greg
Last edited:
Hey joey thanks for the advice, Maybe it is the injectors. I saw some on ebay for about a hundred bucks. How hard are those to change out? The spark plugs and wires are new. and this morning we chcked the wire to make sure they were hooked up in the correct firing order. Is there anything I could run through it to clean the injectors? Can you tell whats wrong with it by hooking the ecu to a scanner? Would the injectors being messed up cause the truck to exhaust all this black smoke? And if the ecu were messed up is there any way to straighten it out? Yeah this is the truck where the guy who owned it before me had pulled out all the 02s and replaced them with bolts. Could that have permanently damaged the ecu? Thanx again!!
Thanxs greg! What do you consider a drive cycle? The plug wire and plugs are new and we double checked them to make sure they were hooked up in the correct firing order. Is there any other sensors that could be causing this and do you think if the injectors were bad it would cause the truck to exhaust this black smoke from te exhaust? How hard is it to replace the injectors if I have too? Any advice you could give me is greatly appreciated!
It's my understanding that the DI ECU is adaptive, meaning it resets it operating parameters (within limits) to what it sees from the sensors.
If the sensor exceeds those limits (your o2's were missing), it will turn on engine lite and the ECU will try ( for several drive cycles (maybe several hundred miles, if it's out far enough) until it accepts the new inputs from the sensors.))
We often encourage re-setting your codes and see if they recur.
Do a search here for "ford injectors" , but I wouldn't replace them until your certain yours are leaking. The stock lucas in these are an excellent design.
Even if they are leaking, they're easy to clean/rebuild.
luck,greg
Thanks Greg my freind should be coming over today with his scanner deal and we should be resetting the codes to see what is wrong with this thing. I'll drop you another note after we do do and let you know what type of codes we come up with.
Hey greg , my freind let me borrow his obd2 and we ran diagnostics on the truck several times between some diving of the truck and clearing the ecu with the obd we got back several codes. The codes are #1a P0118 engine coolant temp circuit High input
#2 P0125 closed loop fuel ctrl insuuficient coolant temo
#3 IAT sensor 1 cicuit high input
#4 P0183 fuel temperature sensor
#5 P0340 camshaft position sensor A-Bank 1 circuit malfunction
#6 P1607 manufacturers control auxilary inputs auxilary outputs
#7 P0103 maf or vaf circuit high input.
These are the codes that are popping up and my freind who's a mechanic hopped on the all data diy and found wiring manuals that showed all these sensors are wired off one initial circuit that banches out to each of these individual sensors So were not 100% sure but were thinking maybe a short somewhere were these wire join or an ecu. If it was the ecu can I just purchase a used one and slap it right in my truck or does it have to be somehow programmed for my individual truck? Do you know what the terms high circuit or circuit malfunction mean? How about that p1607 manufacturers control auxilary inputs auxilary outputs message? Not sure how much you know about wiring or ecu's but any info you might have would be hugely appreciated!!!
