Theirons84

I have a '93 pickup I have been working on. It sat for five years before I started trying to get it going. I ended up replacing the fuel pump, cleaning out the gas tank, and installing a new coil, battery, plug wires, cap, and plugs.

Long story short, I finally got it going and I have been driving it for about two weeks. it ran great other than maybe a slight miss due to what I assume some slightly dirty fuel injectors and just needing to be run. I did the mileage and was getting 31 mpg. This is a 5 speed 2 wheel drive short wheel base truck.

Yesterday, all the sudden, the truck started to run drastically different. I can't remember it happening while driving, so it must have been between start ups or something. Now, it is idling very rough. it shakes violently at idle and it has a ticking sound. Almost sounds like something in the top end, like a lifter or something. It seems to have normal power, or maybe 90% of what it did have, and it seems to run better the higher the rpms are. It really seems as if it is running on three cylinders at idle, or acts like it would if two plug wires were swapped.

I had not had a chance to change the oil yet. I was going to do that this weekend. It was about a half empty when I started working on it, so when I first got it running I just filled it back up to full with good synthetic oil. I planned to change it soon. Mater of fact I have the filter I just forgot to get the oil last weekend.

I'm afraid it may have jumped time or something -like maybe by one tooth. Any hints on what to check? I though about maybe timing or compression. I do have a timing light and compression tester. i thought about pulling codes too, but not sure what those might tell me.

an1176

Check codes. If it has any then research those. If it has jumped time I would think it would run worse at higher rpm but that easy to check. Set your timing mark at 0 take distributor cap off make sure it's pointing at #1, pull valve cover and check your cam mark. It should be just before 12 o'clock. Slightly to the left of 12. While you're there check the timing chain guides.

Flash319

Sounds like a dead cylinder. Run the truck at night and have a look around the coil area looking for arcing. Then i would move onto the fuel side. I have had an injector get stuck before and also had wires go bad in the injector harness. Test each injector for solinoid action, easy to do. Also check your O2 sensor wiring as they have a tendency to get burned on the exhaust.

Theirons84

Just checked timing. Jumped the required terminals and checked. Dang thing is at about 25 degrees advanced. I have to turn my advance knob 20 degrees to get it to 5 degrees btdc, and 25 to get it to zero. I know the jump in the diagnostic port is making contact because the check engine light is flashing.

So I guess it is safe to assume it jumped time. Looks like a tear down is in order. Can anybody give me an idea with what will be involved with the fix? I guess at the least a timing chain replacement is in order. Anything else?

Thanks.

an1176

Make sure get metal guides, water, and oil pump. That should do it. Take a screwdriver and play with the drivers side chain guide. See if you have a lot of movement.

Flash319

It is 25 degrees because your tps is not set up.

Theirons84

Why does the water pump and oil pump have to be replaced in an incident like this?

Flash319

It is almost imposible for the chain to skip. Also the engine will not run if it is off a tooth. Your tps is not set up so you are not getting base timing when you jump the diagnostic. This will also cause your idle to suck. When you put the jumper in the idle will drop and the timing goes to 5 degrees (base timing). The bottom 2 terminals on the tps must be a closed switch with throttle plate closed. Do a search and you will find TONS of info on this subject.

Theirons84

Can you elaborate on this? Does this mean something isn't reading right electronically and it might actually be in time? I had the understanding that the two terminals in the diagnostic terminal had to be jumped in order to check timing.

Theirons84

Would the tps (throttle position sensor?) possibly cause this issue? Are you saying the truck would not run at all if it had jumped time? Please just help me out a little here. This thing thing ran fine for the last two weeks.

In other words what are you trying to say? The TPS just went bad all the sudden? I don't mind searching but I have no idea what I'm supposed to be searching for.

an1176

On my 91 22re with a broken guide the chain had jumped one tooth. It is possible I've seen it myself and fixed it. Again this is easy to find. Put your timing on the crank at zero, remove your distributor cap and make sure it is pointing at #1 plug, pull valve cover, look at your cam gear mark it should be just prior to straight up or 12 o'clock. While doing this take a screwdriver and play with the guide on the drivers side. If it moves you just found your problem. I'll find a picture of what your cam gear mark should look like and attach in a minute.

an1176

You want your crank pulley to look like this pointed at zero.





Distributor cap off rotor should look like this pointed at #1 cylinder.






If your cam is in time it should like these two pictures. If everything is like this you haven't jumped time.

Flash319

If the chain is out onewhole tooth you would not be able to drive it if it even runs. Yes your tps may have gone bad or just needs to be adjusted. When the throttle is closed the computer changes the timing and injection. It knows when to do this buy the tps. If it is not adjusted right the ecu does not know you are at idle. Also you can not go to "base timing " mode for setting your distributor timing unless that switch is closed in the tps. So your timing will be all over when you are trying to set it with a light. Showing like 25 degrees advanced.

Theirons84

Well I guess it is confirmed. I Put crank pulley at zero, and pulled distributor cap off. Rotor is pointed at #4. Google says firing order is 1342. Hard to believe it is even running. It cranks every time, and it shakes violently and has a pronounced tick coming from the valve cover.

Theirons84

Thanks for clarification. I am afraid it has jumped time though. I don't know what other explanation there is. See the last post I put up.

Flash319

Also it would not just "jump timing". It would rattle and bang like a diesel for a few thousand miles then Jump....maybe... Also cam timing and ignition timing are two different things. If your engine was not making noise like a diesel your cam timing is fine. Check your tps with a meter per the manual. An easy way to check is if you short the diag terminals the idle will drop. If it doesnt your tps is out.

Theirons84

OK I will check that. The idle may have dropped but I'm not sure. The noise from the engine is pretty rough.

Flash319

I went back and read your first post. I still think you have a dead cylinder / head gasket gone. They will go between cylinders someimes (had one do it) so no coolent Sucked in and will run like crap. Since it was all of a sudden that seams logical.

Flash319

If it is that rough it is not the tps. They will run ok with the tps unplugged so that is prob not your issue.

an1176

Can you take a picture of where your rotor is pointed and post it?
My 22re with jumped tooth ran like crap for over 100 miles and brought me home. My symptoms were different then yours though. Mine idled ok but wouldn't pull, I couldn't get it to 50mph.