I have an '85 truck that appears to have a 22re from a '90 (based on the code on the throttle body intake). When attached to a digital tachometer, it acts like it has a random variation on the idle; It acts like it stumbles a little here and there, but otherwise runs great. No codes.

Over the course of the last few months I've replaced the vacuum lines, the catalytic converter, the fuel injectors (installed the injectors for an '85 model), replaced the brake booster and master, plug wires and cap/rotor, and the boot coming from the air box to the throttle body intake, and the coolant water temp sensors.

Getting ready to go thru the plug wires and cap/rotor in more detail. Have to get it to pass smog in the next few days, and had not expected problems, but, well, here goes.

 

Damn you have to smog a 30year old rig. That sucks. What's the timing at? Does your smog check include them putting a timing light at the smog check? If not and your Gavin troubles passing retarding the timing may help

Good luck hole this helps.

 

The engine and exhaust was pulled from a truck with two O2 sensors (presumably a 1990), and at this point I'm trying to find a way to plug the downstream access point. Looks like a 18 X 1.5 bolt; I'm thinking if I just weld it on there they hopefully will let that go.

I'll double check the timing. It seems like when I drop it down to factory spec, the idle does not stay consistent. I may drive it around town and find that it is now trying to idle at 600 instead of 750, and also the other way 'round (it may start idling at 900). Other than double checking the plug wires for consistent resistance, and the potential of some sort of tiny vacuum leak, I don't know what else to look at.

The smog shop said they need it to idle at factory spec +/- 100 rpm, so I'm guessing it will do that. Just don't know how clean it is running if it has this random rough idle.

Is it possible that the coil could be delivering an erratic power supply to the plugs? I can't think of very many things that could do that. If it was a plug wire resistance, it would cause a problem with each revolution of the engine? So that sends me towards either the coil or the vacuum system.

The guy I bought it from had it pass smog, but given the condition it was in, I have no idea how he did it. I've fixed a lot of stuff in the last year!!

 

Couple things may cause similar issues. Fuel filter been changed recently? Is the fuel tank and fuel strainer needing to be cleaned. Kind of a PIA but may be related. Is it like this when cold or doesn't matter if it's warmed up or not? If when mainly cold then maybe a plugged egr unit? Long shot I know but who knows.

 

Does it warmed up, or is noticeable then. When it's cold it has an elevated idle, and you can't notice it. Replace the front fuel filter when I did the fuel injectors. Inspected the fuel sock when I had the tank off to do the Chevy 63's on the rear. I have verified the fuel pressure at the rail, and that the return line is clear to the gas tank.

If I slow the idle down to spec, I can detect a sporadic flutter. I've had folks say that Toyotas do that, but I've had other Toyota's that don't. go figure.

 

Have you put a fuel pressure gauge at the fuel rail? A lot of people see "good fuel pressure" at the rail and assume it good. Later they put a gauge on it and it's way under pressurized.

 

I had found a procedure to essentially estimate it by fuel flow rate at idle. Not perfect, but that problem seemed to be solved with the correct fuel injectors (the '90 computer provides more voltage than the '85 computer, as per Marlin's evaluation about a year ago)

I'm wondering about the nature of the coil. Do they either work or not, or could it "bobble" while providing spark to the distributor?? The darned thing is likely to be 30 years old, but may be fine.

In the morning, I'll pull the distributor cap, check the wires and plugs, find the procedure for setting the timing (it's been a while. seems like you have to jumper a connection on the driver's side diagnosis trio) and then go from there. Got to cover the basic bases first I suppose.

 

I have an 87 with an 85 22R in it. I put it in it. It tries to idle a little too fast and if I lift the gas pedal with my toe the engine returns to set speed. I think I need a heavier spring or lube the accelerator cable.

Just my 2 cents, hopes it helps,
grey

 

OK, so when I hook up the jumper to set the timing, I'm getting two diagnostic codes. A 2 and an 8. So I proceeded to check the resistance on the output pins of the AFS box. It's not passing the test. So the first question is whether I should be concerned about which box I have and how it's talking to the computer. The engine, as far as we can tell, is from a '90, and the AFS box appears to be as well. If the plug-in wire for the AFS box came with this 90 engine, should I expect a conflict with the '85 computer?

At this point, I'm searching for a replacement AFS box............

Here's the link I'm using for troubleshooting. I'm getting no reading on test #3

http://www.4crawler.com/4x4/CheapTri...tml#AFMtesting

 

Check for play in the distributor mechanical advance. Pop the cap and twist the rotor. If the spring tension isn't consistent the mechanical advance can 'bounce' at low rpm and cause erractic low rpm fluctuations.

Just a thought.

 

So, the other evening I ran into Marlin and he says 'Don't worry about the air box'. If it's running, then set the timing and check the "0" point on the TPS (the little set screw under the throttle body intake is for setting this. He also said that some folks will try to use this to set the idle, and that is not what this set screw is for.......).

So I half listened, and took the lid off the air box to inspect it, and it was clean as a whistle. I did the active functional test on it, and it passed that; I just ignored the one static test it was not working on.

Took it down and got it smoked, and it did great on everything except the CO level. It passed, but was running about twice what the "average" is for that metric. But, bottom line, it passed!!!

 

OK, latest challenge being thrown at me by the truck. Took it for a test ride up in the hills, and it sputtered and died and would not restart. Found that the "Engine" fuse (bottom center fuse in the main fuse compartment in the footwell) had blown. Not sure what would cause this, but it's going to make me nervous till I figure it out.

 

That is a weird one. Have you checked to make sure all you ground are good in the engine compartment. Maybe you have a bared wire, that would suck to track down. Good luck. Hope this helps.