Hadn't been on this site in a while b/c truck has been running great, but here I am again looking for help because truck not running so good. 94 Pickup w/ 22re wouldn't start installed new plugs, wires, cap, rotor. Still wouldn't start, advanced ignition timing slightly, engine started. Seemed to be ok but started missing during acceleration and throughout driving range. When going from idle to wot engine would backfire. Basic problem is engine is missing and surging. The only way I can get it to run half-way decent is by advancing ignition timing all the way, otherwise it won't start or will backfire. Checked cam and crank timing and its right. Thought I had a bad fuel injector on the #1 cylinder but that wasn't it. I put a new head and timing on 50,000 miles ago. Worried that there may be coolant entering combustion chamber b/c it seems I am losing a little coolant. Compression check came out ok with all cylinders just below 150psi. I'm stumped. Any help would be greatly appreciated. Thanks in advance.

Put your timing and idle back where it needs to be and check your TPS adjustment. Root of all evil. Start there.

Also, check for vac leaks. My 22RE was running pretty cruddy, found a crack in the air intake tube's rubber boot near the throttle body. Sealed it up, now it's runnin' great.

Pulled throttle body off this afternoon to clean it out. Lots of gunk on the back of the throttle plate. Looked like carbon and oil. Vacuum lines on top of the throttle body were plugged up, cleaned em out. Loosened TPS and adjusted it while working throttle manually, but my don't remember correct procedure how to test. My haynes manual doesn't cover it. Haven't looked at FSM yet. Not getting better. Still driving the truck but it's getting really annoying. Sometimes its like a bucking bronco other times it seems fine. Runs better w/ throttle open rather than keeping constant speed or idling. I havent had much time to mess with it. Working two jobs by the time I get home it's getting dark. Thanks for the advice.

If the t'body was gunked, then your EGR is probably in the same shape. If not wanting to tear it apart straightaway, get some Seafoam to suck through there. NAPA.

Ordinarily a plugged EGR gives you a little hesitation around 2400 rpm or so. Simply sounds like you need to set aside some time for routine maintenance. It's the only way it'll get done.

Tested and adjusted TPS and it checked out ok. Did the seafoam treatment in fuel and vacuum lines no improvement. What confuses me most is the engine won't start cold when ignition timing is correct and runs best with timing fully advanced. With it backfiring like that it must be running too rich and exhaust has heavy fuel smell. It runs the worst at low rpms and under load during acceleration.

Now thinking I may have a cylinder head or head gasket problem. It's losing coolant and I can't find a leak. I did a compression check when I first started having this problem and all cylinders were about 150 psi. No oil in coolant or coolant in oil but it is definitely loosing about 1/2 gallon every 200 miles or so. No smoke in exhaust. Is there a way I can test for this without taking it to a mechanic? I would like to be sure this is the problem before I pull the head. I just replaced the HG about 70,000 mi ago and put a nice rebuilt head on. Maybe I didn't do a very good job. Was thinking about re-torquing head bolts. Don't know if it would help at all.

One test is a cooling system pressure test. Put a gauge on the radiator cap and run the engine and see if the pressure rises and falls with RPM and/or pump up the cooling system and see if it slowly leaks down - might be a leak only under pressure.

2nd test is to pick up a chemical test kit for the coolant to detect the presence of exhaust gas contamination. NAPA sells a kit for around $20 as I recall.