Dom2332

So I've taken care of most of the issues on my swapped out 3.0 The one that is still puzzling me is the issue of when it gets hot and up to operating temp. Truck runs just fine when cold but once it gets hot it starts to sputter and miss. It also wont idle and dies if I dont stay on the throttle. If I look at the exhaust while giving it throttle I can slightly see black smoke coming out telling me it may be running rich. There are is no CEL so I have no idea where to start.

Any suggestions? Has anybody had these symptoms before?

What I thought was weird after installing the new ECT sensor is that I ran the truck parked for half hour with the hood up and it never died. Thought both my problems were taken care of(cold start and oper temp issue) so i closed the hood and within 5 minutes the truck shut off. I restarted it and it was doing the rough/no idle and sputtering issue again. Seemed like the extra heat with the hood closed made it start doing it or something. Could it be a vacuum issue or emissions issue?

Stetson_md

What kind of truck is it? Is it a swaped in 3.0 or swaped out 3.0? You'll get mote answers if they know what your working on.
Quick way to test if its rich is to pull the air filter and see if it perfoms slightly better If it dose Its rich if its worse its lean.
Can't help you more then that I'm more into carbs

Dom2332

Its a 1995 pickup with a 3.0. We replaced the 95 3.0 with a 3.0 from a 1991 4runner that had a re-manufactured engine. Before the swap, the 4 runner had the same issue when it got hot. It would cut off and die. It would start right back up but you had to stay on the throttle. I will double check the air filter but looked good when we swapped over the engines. Maybe I'll just buy a new one in case.

Stetson_md

What no man that's not what I meant I mean take out the air filter run the truck see if it getting more air improves the way it runs if it dose its rich put the air filter back in then adjust the mix accodingly see what I'm saying? When you don't have a air filter at all on the truck the engine runs leaner compared to when you do have on on it or at least on a carbed truck it dose

Dom2332

Well this morning i got a code 71 - EGR system malfunction.

Could a bad O2 sensor cause this. Is it possible to clean the EGR and other components? Could this be my problem?

Stetson_md

it probably could but I really have no idea about the newer motors so

Stetson_md

Bump again, anybody know

Kiroshu

EGR valve stuck open...?

Cold start injector leaking internally into intake...?

Fuel injectors leaking internally into intake...?

Air Flow meter faulty/out of specification...?

osv

o2 sensor not relevant to egr, and yes, you can clean the egr to some extent.

egr valve is opened by vacuum, so unplug the vacuum hose from the top of the egr, and plug the hose with a screw or something.

start the engine, see if the symptoms change... real simple.

if the symptoms change, put a separate vacuum hose on that top egr port, and suck on it while the engine is idling... that should open the egr, and either stop the engine from running, or make it run really rough.

that's how you test egr functionality.

Dom2332

Thanks guys for the responses. I will try and test the EGR valve tonight as stated above. It almost seems like something is sticking and it only does it when the engine is hot. Once it gets hot it starts missing and sputtering and wont idle. If im going down the road i can feel it jerk. But it comes and goes. If I keep giving it gas while in park it will clear up for a few a bit then start again. When its doing it I can look at the exhaust and faintly see black smoke which is telling me its running rich. If i let the engine cool down then start it up it idles fine until hot. Got me puzzled!!

Dom2332

Ok so this evening I tried a few things, none of which helped.

I notice the o2 wiring was slightly melted from the exhaust and had wires exposed. I repaired that.

Took air filter out, was slightly dirty so I cleaned it.

Sprayed down the throttle body with cleaner, was dirty but not bad.

I took the egr hose off tried the suck method as stated above when cold idle, truck wanted to die. Also when truck was hot and rough idle I took the hose off plugged it tried the suck method and it died. So I think egr is good.

After that while the engine was hot and still running rough/low idle(100-200rpm) I unplugged the connector for the cold start injector. No difference.

If I give the truck while it parked I can see black smoke. If I stay giving it, rpms go up and down then its like a switch and will start idling fine just a little higher 1200 rpm vs. 800. It will idle fine for a few minutes then if I touch the gas it starts again.

Could my tps be bad, or not adjusted properly. Afm faulty like stated above. What about incorrect vauum line placement. i reset the cel and it hasn't turned on again.

The engine is a remanufactured s&j engine. Like I said runs fine when cold then after 20 min of idle or driving it starts doing this. Driving me nuts!!

Dom2332

Ok so the latest is I went for a 15 minute drive to town this evening to go put gas. Truck ran fine all the way to the gas station just had high rpm 1200.after putting gas When I went to start the truck it had super low idle like 100-200 rpm but wouldn't die I would give it gas and it was sputtering. Good thing it manual I was able to rev high and get home. On my way home I felt it jerk and sputter a few times. When I got home it was idling high again 1200 rpm. I popped the hood and started tinkering with stuff. When I got to the AFM I knocked on it and the truck had an idle surge. Come to find out it seems like the electrical connection isn't making good contact. If I squeeze the connection it idles fine. If I twist on it or shake it it acts like it gonna die. So tomorrow after work ill be cleaning and inspecting the AFM connection. Fingers crossed.

Also had the cel come on again with code 71 again. Egr system malfunction.

And I checked my mileage, I'm only getting 15 mpg, does that sound right for 1995 3.0 pickup??