Spacecataz

I let my wife drive the vehicle to work, and it ran fine until she left. She tried to drive home and it started a temper tantrum of epic proportions.

She was on cell with me and said it was suddenly stumbling, idling very rough, would cut out unless she gave it gas, and had no power up even small hills. She also mentioned she had no power brakes at times. Before that it ran fine, it didn't have the acceleration it once had, but otherwise a rock solid daily driver.

She limped it home (about 3 miles) and I let it sit to the next day when I could get a look at it. I scanned for codes and none were found. So I started it. It was a hot mess, loped at idle like it had a high lift cam, stumbling in gear, high idle, and ye old valve ticking from these engines was MUCH louder. Yet, no codes to speak of.

It stumbled and quit, and after I tested again I got a code for the TPS sensor. Fair enough I thought, I didn't think a faulty TPS would do all of that, but at least I had a starting point. I tested the TPS voltages, and sure enough it was gone. I replaced the TPS, confirmed the voltages and started it up.

Same issues, loping/surging at idle, odd exhaust smell (not like gas but "strong" exhaust?), high idle and generally knackered. I then heard a light hiss from around the intake area while the engine was running. So i says to myself, "self, that's a vacuum leak". Again I am not a man of means, so I used the old cigar and hose trick to see if I could smoke out any vacuum leaks, and used carb cleaner as well for the harder to reach areas. I found ONE vacuum leak, at the PCV valve to intake hose. It was cracked, so I replaced it. This time when I started it the high idle was gone, but the car was still loping at idle and in gear, badly. I let it warm up, and the idle got a fair bit better. Then it promptly shut off and wouldn't restart. After finding and kicking a small selection of random mules out of frustration, I started to suspect it was a cold idle problem.

Long story short, I replaced the MAP, IAC, and CTS. None of these fixed the problems, but increased the idle quality a good deal. I unbolted the exhaust from the manifold, as I suspected clogged exhaust for some reason. The only result was the neighbors being able to hear the horrible sounds from the car, as basically it then had an open header.

Today I thought it MIGHT have an good enough idle (still loping but minimal compared to what it was before) and i took it around the block for a test drive. I heard the distinct sound of a blowoff valve when the thing was about to shift, like I had a turbo. I do certainly not, have a turbo. I had to hammer the gas to get up to any descent speed, and it acted like I had a potato up my tail pipe. No power at all, stumbled a bit when I stopped and acted like it was going to die a few times.

I "limped" it back into the garage, and there it sits. I've replaced the, IAC/TPS/CTS, checked for vacuum leaks, cleaned the EGR valve/solenoid, and I can't check fuel pressure yet because 96's have no schrader valve and I have a test adapter on order.

Only things I can think of left are basics like fuel and spark. I'm dumbfounded and feel like taking the thing to couples counseling to see if it can tell me whats wrong. So far, it shows little to no interest.

65Delta

I wonder if the vacuum diaphragm in your brake booster let go. It would cause a massive vacuum leak that may/may not be easy to find. Pull the line, plug it, and see if there's any improvement. You'll have manual brakes at this point (obviously) but it would be ok for a spin around the block.
The 2.2L likes to leak Dexcool around the head gasket. That's really it's only bad habit.

Spacecataz

Hmm, I sprayed cleaner on the valve and partially pinched the hole when I was testing for vacuum leaks, and found no change but you could be right. That could explain why the "blow off valve" sounded like it was close to the drivers side, and why shifts were erratic and difficult. Tomm. I will pull and plug it. Thanks for the help.

Spacecataz

Okay, so I tried to remove the intake to booster hose and I was having to use way more force than I thought was nessecary (new'sh hose) so I took a pair of vice grip pliers and manually crimped the hose. Car started, and ran worse, if anything. Skipping while revving etc. This time I did smell a strong puff of gas, as I approached the hood. I pulled the 02 sensor as a small side test, and no change. The computer threw a code after I did it, so there is that. I've since plugged it back in and deleted the code.


I took a break too have a staring contest with the car shortly after. It won.

65Delta

Still sounds like a massive vacuum leak somewhere along the way but you'll need to rule out some of the basics. Are the plugs wires all ok? How do the plugs look? As the 2200 is known for head gasket leaks it would be worth a cooling system pressure test just to rule out a leaky gasket. O'Reilly has the pressure test kit available as a loaner tool. How's the fuel pressure regulator? If you still don't get anywhere you may need a Tech1A/MTS3100 or equivalent to look at the data feeds while she's running. It's a good whodoneit.

Spacecataz

I rebuilt the upper end about 9 months ago. New head from an S10 donor (28k miles), lifters, rockers, pushrods, plugs, wires, etc. So I don't think the head gasket is leaking. Its not burning coolant, and there is no coolant in the oil. That's also one of the areas I sprayed with cleaner. A leak down test is a good idea though just for peace of mind.


The regulator I haven't tested as I don't have a mighty vac or similar, and I know first hand you can test them with one and have it "pass", and the spring still be bad. I'll probably buy one from rock auto. I haven't pulled the plugs yet, but I suspect they will be blackened. I'll do that tomorrow.


There is one other thing. About a month ago I had a big oil leak from the valve cover gasket. When I replaced it, it had a large chunk missing like it had exploded. That was right about the time I noticed one of the vac hoses on what I "think" is the DPFE? was blown off. Whatever it is its directly under the air intake on the side of the engine, and its connected to the vacuum harness.


It has to be something like vac, or fuel, or even spark that doesn't set a CEL.

Spacecataz

Pulled the plugs, promptly scratched head.


#1 smelled slightly of gas/carbon buildup/slight heat glazing
#2 smelled strongly of gas/normal wear
#3 (was loose?) slight heat glazing
#4 (was loose?) smelled very strongly of glass, slightly wet, blackened (closest to FPR)


Here are pics. Pugs are in arranged to correspond to the order above. Second picture is the #4 plug. Second picture is poop and doesn't show how the plug was slightly moist.


http://imgur.com/2EPNKxR
http://imgur.com/vvsFLx2


I've never seen 4 diff cylinders have 4 different conditions, and 2 of them be loose. Am I incorrect or does this point to a bad FPR and/or ignition? Note: #3 and #4 were closest to the oil leak I repaired. Also as I know 1 and 4 seemed to be dry/wet fouled and they are on the same coil.

65Delta

That's a lot of variety considering all the plugs came out of the same 4 banger. The clean plug looks almost steam cleaned while one of the other looks like it's been running pig rich. What made you replace the head originally? If you pull the coil packs and module the parts store should be able to test them. If you unplug one injector at a time do you notice any difference in how she runs? Can you confirm you're holding fuel pressure? Not sure of your location but my local U-Pull-It yard (LKQ) runs a Memorial Day sale on parts. It may not be a bad idea to put together a list of all the possibilities, pick up some cheap test parts, and systematically eliminate the possibilities.

Spacecataz

Well, I smell gas in the oil now, strongly. So, I'm thinking bad FPR or injector problems. I still can't check the fuel pressure till Monday or so. The FPR is original to the car (180k) so if it is bad, I suppose I've been lucky so far. If it's not on its way out, its on borrowed time at least. I think I'll just replace it and grab a new set of plugs while I'm at it.


I replaced the head a bit back because one of my deceased fathers friends wanted to, I don't know bond with me or similar (note: I'm 40) and "help" me with my routine maintenance/tune up. He got a plug cross threaded and I couldn't get it out. So, it was just a good idea to replace everything I could around the same time. I've since ran him off, lol.


It's obvious 1 and 4 coil isn't firing that well. Can a bad or weak coil pack let extra fuel into the cylinders? It's weird only 2 of the plugs had fuel related problems, and those two are on the same coil. And those two are near the FPR and at the start of the return line.

65Delta

Gas in the oil is a good lead. I'd replace the suspect coil pack first, check resistance on the plug wires, and see what happens. If the coil pack is weak or dead the gas being introduced by the injectors is being dumped right into the crankcase, past the piston rings. If that doesn't do anything then yes, on to the fuel system.

Sounds like the friend of your father's was some help . I wanted to rule out things like severe overheating that cracked the head, etc.

Spacecataz

Welp.


I got the pressure tester adapter today via UPS. I tested the fuel pressure, and on prime I got 45, then it settled down to 40 psi. Turned the ignition off and it dropped to 20 and "held". I got 40 psi at idle firm. I don't have much gas left in the tank so didn't want to do more.


My multi meter is knackered it seems, thus I cant check the injectors for resistance quite yet. I can do it when I replace the FPR though. I tried the stethoscope trick but as these are bottom feed injectors and sit flush inside the rail I couldn't hear anything. I think i'll just rent a noid light and a multi meter on top maybe.


I still have the coils on order and plan to install them with the new wires and plugs.. but am unsure what to do next.

65Delta

Bottom feed port injection...I can now perfectly picture the engine you're working on. I had a '96 Corsica 2.2L that I sold in 2013. I didn't know that system was universal across the FWD GM cars in '96 but it makes sense.

Have you tried pulling the vacuum line on the FPR when running? If you get fuel out of the top of the FPR the diaphragm is ruptured. FP looks ok though.

The big "box" on the back of the intake (bottom feed port) makes checking some of this stuff a PITA. Getting to the injectors while she's running may be a problem. I was going to suggest pulling the retaining clips on the injectors and unplugging them 1 at a time to see if you notice a change in idle.

What kind of vacuum are you pulling at idle? You can rent a vacuum pump and use it for the gauge on the end. If everything else comes up negative I'd do a compression test to rule out bent valves, etc. Everything should check out fine and you can add it to the checklist of things that were checked.

Spacecataz

I got the coils and wires on today. I love how you have to make a choice between removing an engine mount and chocking the block versus going in from the wheel well. Anywho, when she's back "running" today Ill test the FPR, but most likely change it anyway. even if it passes the vacuum test the spring still may be weak and letting pressure through.

Spacecataz

Got the engine back together and tested the FPR. Unplugged the vac line and it did jump up 5 pounds upon doing so... however randomly it would drop 10 pounds and climb back up. No gas from the vac line as I could see but the line smelled strongly of gas.


Most people will tell you to wait for gas to come out and sometimes it takes a few minutes but with what I had already seen and the gas already in the oil, I didn't want to run it very much. So, im pretty sure the weak coils didn't help, but its probably running way too rich from a bad FPR (also maybe injector but I doubt it?)

Spacecataz

Changed the FPR!


1. Pressure drop from prime went from 40 to 20 to 40 to 30
2. I swore
3. Maybe #4 injector is bad
4. Silent scream

65Delta

How is she running with the new plugs/wires, coil packs, & FPR? You may be on your way to purchasing a scan tool for this one .

Spacecataz

Still running rough. Not surging as bad, but still a small amount. Honestly I h avent driven her again as the oil needs to be changed with all the fuel in it, and I only like to run her for brief test periods. I checked the resistance on the injectors and got a steady reading of 12.5 ohms on all of em. I don't think gas in the oil would make it run rough as it is though.


Turns out the FPR is on the return line and not on the feed line like I thought it was. So number 4 being pig-rich adds a different spin. Only thing I can really do now, is maybe have the injectors cleaned, (one of the o rings was a bit knackered too) do a compression and leak down test. Then if none of that works, take her to be scanned.


Is there a way to test to see if the injector is faulty at home other than a resistance test?

65Delta

A resistance test is a good first step. The injector balance test (disabling the injectors 1 at a time to see if one has no effect on idle) is next. Do you have any fuel leaking from the injectors or O rings? If you leave the Fuel pressure gauge on the rail and shut her down how long does the system hold pressure?