Sheriff420

On the way home today my car had a couple hiccups.

I got on it to get on the highway and I lost power as if I had taken my foot off the gas, then I did take my foot off the gas and hit it again but only about half throttle and got on my way without any issues.

About 5 miles down the road, after two stops, I was accelerating again but this time only about 1/3 throttle and it did the power loss deal again and quickly recovered.

I'm thinking it might have something to do with the coil because I was looking over my vacuum lines while I was at the parts store and I moved the coil wire on top of the body next to the shock since it was hanging down kind of close to the exhaust manifold.

I'm thinking that has to have been it because I touched it then I had a problem about 10 miles later.

Has anyone else had this issue?

I also thought it might be the TPS having a flat spot in it but it isn't consistent and the TPS isn't that old.

About the vacuum leak, If the three way check valve behind the intake manifold were bad then would it make your vents stop blowing when you accelerate?
My cruise control works fine, so I know that line is fine.

Sheriff420

After I got home I revved the engine up to the red line a few times with a smooth pedal motion (not just stomping it) and it did the cutting out deal a couple times.

I replaced the vacuum line that goes from the check valve behind the intake to the T behind the driver headlight and tested my ignition coil.

When I went to start the car, it wouldn't start. It would stumble for a moment (1-2 seconds) then die.

The coil test from the Haynes manual showed 0 ohms for test #1, 8 ohms for test #2 and 15 ohms for test #3.
Haynes says that it is supposed to be 0 ohms for test #1 and very high but not infinite for test #2 and 3 so I'm going to get a new coil tomorrow and see how it does.

If the new coil doesn't fix it then I'm going to see about checking the fuel pressure.

TomP

I've had harness wire trouble by the coil before (first got the car- used a blue splice connector to hook in an aftermarket tach- years later, from vibration, the splice connector almost cut the coil signal wire in half!). The wiggle test = wiggle the harness wires (not spark plug wires) while the car runs will usually show a bad wire.

You're definitely on the right track because I was going to say that a dying fuel pump can also act the same way. I'm not sure of the Haynes' tests but it does sound like your coil's shorting internally to ground. Let us know what you find out!

Sheriff420

New coil, still no start. It started raining right before I got the coil in there too, at least it's warm outside. It might be the fuel pump because on the first try it will stumble like it wants to start for about 2 seconds then the second and third try (key off then back on each time) it will just stumble a little like a couple cylinders fired but it's still a no go. So I'm going to have to get a fuel pressure test kit and see what it is.

TomP

If pressure's OK, check the timing too. When my first pump died (verified with pressure gauge), after I was done, I had pressure but the car wouldn't start. I started regular diagnostics and found out my #1 spark plug was destroyed- no center electrode. Turned out my timing was so far over advanced it was off the scale. I put it back to 10 degrees advance and the engine started right up.

Sheriff420

I checked the timing and it is at 0º (TDC) and it is supposed to be at -10º.
I'm not sure if the way I checked it will be accurate though since it won't start.
I had the girlfriend bump the key for 1-2 seconds and was able to get about 4 flashes from the timing light per bump. But what I'm not sure about is accuracy with doing it that way because the crank is being turned by the flywheel instead of being pushed by the pistons. The timing chain has 200,000 miles on it and I don't know if the slack that I'm sure is there will affect the timing test by checking it with the starter vs. the engine actually running.

TomP

I've never thought of checking timing that way so I can't say for sure. Any timing chain slack wouldn't affect it that much- if it was enough to lose 10 degrees then you'd have even worse problems (valve timing would be off too). Did you disconnect the one-wire EST connector (tan wire with black stripe) in the main engine harness (by the heater motor on the passenger side) before you checked timing? If it was still connected that means the computer was still in control, and you won't be seeing the "real" base timing value.

You'll have to see after you check fuel pressure.

Sheriff420

I did disconnect the EST connector before checking.
I'm going to get a fuel pressure test gauge today and check that.

The thing that baffles me is that it was running fine when I parked it then I changed that vacuum hose and poked at my coil with the multimeter and now it won't start back up.

Sheriff420

I sprayed some carb cleaner in the throttle body and it started for a few seconds (longer than it has been) then died.
I started it again and try to give it gas and it died immediately.

I know it has decent spark because the plugs/cap/rotor aren't that old and it will run on carb cleaner.

It seems like the fuel injectors aren't firing like they're supposed to.

I have fuel coming from the pump and back through the return line. Haynes says to put a jumper in the diagnostic port to kick on the fuel pump and it should pump about 1/2 pint within 15 seconds. I just used the key so the fuel pump only primed but if it had stayed on longer then it would have hit that 1/2 pint mark by 15 seconds.

I cleaned the battery lugs since that's one thing Haynes said to check.

The injector 1 and 2 fuses are good.

I think my next course of action will be to try to adjust the timing.

How would I go about testing the ECM and whether or not the injectors are firing? The injectors would be easy if they weren't embedded in the intake manifold.

And another thing, I'm sure I have that PROM issue since on a cold start, the car will surge when I take off until it gets up to temp.

TomP

Were you able to check the fuel pressure with a gauge? You'd need both pressure and flow to make sure it's a good pump; you could be a few PSI low and the car won't run (e.g, 28 psi = no start). Be careful with starting fluid; if the motor backfires and the fluid has puddled in the plenum, it'll explode out of the intake.

Easy injector test = get a "noid light" set - well really you just need one light. You unplug an injector and plug this light (really just an LED and a resistor) into the harness; then you watch for the light to flash. Harder test = they sell an injector tester - that you use in conjunction with a gauge - that will pulse the injectors as you watch for pressure drop; I bought mine from Sun years ago but luckily never had to use it.

Sheriff420

I was standing to the side of the throttle body with a fire extinguisher right next to me while doing that.

I need to get a gauge since you said that, I figured that it was flowing pretty good so that should be good enough.

I'll carry my multimeter out there tomorrow when I mess with it some more and check an injector for power.

TomP

Yeah the fuel flow numbers usually match the pressure numbers, but the gauge will tell you right away. In fact whenever I have a problem with my cars I throw the fuel pressure test gauge on right away to make sure the fuel system isn't the problem. Well unless the battery's dead

Sheriff420

I tested the fuel pressure, it is at 45psi.
I pulled the only fuel injector pigtail that I can get at without too much of a fight and tested it with my multimeter. It is getting voltage but the funny thing is that the car started and ran with a misfire. I gassed it a little using the throttle linkage and it revved up (with a misfire).
Seemed right to me.
I reconnected that injector and started it and it runs like normal now.
So now I'm scratching my head as to why it didn't want to start in the first place.
The only thing I changed was the coil, the rest of what I did to it was diagnostics.

I checked the timing since it is running now and it is showing a little past 0º.
The timing marks count down to 0 from left to right and the timing is set a little to the right of 0.
I'm going to set the timing where it's supposed to be and play with the idle screw a little tomorrow and see what happens.

Sheriff420

I set the timing to 10º BTDC like it is supposed to be. The car was running smooth and everything seemed right.
When I was putting the socket on the distributor hold down bolt I turned the distributor a little bit and realized that it wasn't tight to begin with, I think that's why it got out of time in the first place.
I reconnected that tan wire that you have to unplug to set the timing and disconnected the battery for a few minutes to clear any codes that may be present. The service engine soon light was on and I think it was from having that tan wire unplugged to set the timing but I unhooked the battery anyway.

When I went to start it again after reconnecting the battery I am back at square one. The engine will catch and run for a moment then cut off. If I give it a little gas it dies immediately.

Sheriff420

I tested the fuel pressure the other day on the line coming from the tank, next to the ac compressor and it read 45psi.

After a lot of use on the search function I am leaning toward the fuel pressure regulator but I'm still not sure.

I put the fuel pressure gauge on the schrader valve and it read 45psi then as soon as the fuel pump stopped priming it took about 2 seconds to drop down to 0.
I pinched the return line with some vice grips and the gauge read 72psi while priming and quickly dropped to 0 again.
I pulled the vacuum line off the fuel pressure regulator after running the engine for about 20 seconds and there wasn't gas in there but I could smell gas fumes in the line.

I also checked the codes and I'm getting a code 42.
I disconnected the battery after adjusting the timing the other day and I ran the engine for about 30 seconds, about 4 or 5 hours after it wouldn't start (see previous post). It fired right up like nothing was wrong.
Just a little while ago I started it (after reading the code) and it started just fine aside from the idle being a little high and the code making the SES light be on.

So now I don't know if it's the fuel pump, injectors or the fuel pressure regulator.

Thanks for your help so far Tom, I sure do hope someone that has had the same problem I'm having sees this thread sometime soon. I'm just glad that this isn't my only vehicle or I would be just a little upset by now instead of just scratching my head.

Sheriff420

The EST connector was unplugged the other day so I reconnected it and I still had the code 42 after starting it but the engine has been started a couple times since then and when I went to check the fuel pressure again (with the plans of pinching off the supply line after the pump primes the fuel rail to see if the check valve deal in the pump was bad) it read 45psi and as soon as the pump stopped priming it actually held pressure.
I started the car and after a couple minutes of running the pressure dropped to 39-40psi (it was jittering between the two so I assume that's the pressure regulator doing it's thing).
I pulled the vacuum line off the fuel pressure regulator right after I shut the engine down and didn't see or smell gas so I assume it's ok.
Also, the SES light is off now.
So I guess it's ok, just need to test drive it and find out for sure.

Sheriff420

I finally got around to test driving the car tonight.
It did fine aside from the hesitation from a stop about a mile after I took off (I assume that's the PROM issue that's associated with cold start hesitation).
I gunned it a few times and burned out just seeing if it was as it should be and it was.

I went 7 miles and dropped off the girlfriend then leaving her house I gunned it again and the car died. At first I let off the gas and hit it again assuming that it was my original issue but it was clearly dead so I slapped it in neutral and pulled to the side of the road then called my mom and had her bring me my truck so I could drag it home.

I tried to restart it a few times and it was the same deal where it will start for a couple seconds, stumbling the whole time then die.

I was poking around the engine while I waited and I noticed something that doesn't seem right to me. When I grabbed the pigtail for the oil pressure sending unit and pushed it in a little it let out a buzz like it was trying to do something. It does it every time I push the pigtail in and the connection has oil in it.
I believe I read somewhere on here that a bad oil pressure sending unit can kill the motor, is this true?

A recap of what I've done so far is:
-New coil.
-New spark plug wires.
-Set the timing to 10º BTDC, it was a little past 0º because the distributor hold down clamp was loose.
-Plugs are only a couple thousand miles old.
-Cleaned battery terminals.
-The fuel pressure holds steady at 45psi with the key on/engine off.
-Fuel pressure after running for a couple minutes was 39-40psi.

The original problem hasn't changed and I bet if I go to start the car after it gets good and cold that it will start because it did that once before. It wouldn't start after running it doing the fuel pressure test then after it sat for a few hours it cranked right up as if there was nothing wrong to begin with.


This thing has me stumped. If I can't figure it out then there might be some parts (or an entire parts car) for sale on here some time soon.
If it comes to that then I'm glad I only gave $1000 for it and haven't dumped hardly any money into it.