[Monomer]

Seems to be common, and though to diagnose.

The car: 1994 sundance 2.5 n/a
-New HG
-New cap/rotor; plugs/wires
-TB gasket (the thick one)
-Intake gasket
-Ground straps check out (I'll double check tomorrow - I missed the intake ground)
-Vac lines all check out
-PCV new
-MAP new

Symptoms:
-Car revs high upon starting, then comes down to a normal idle
-Bogs coming to a stop, has stalled before (intermittent)
-Bogs on the low end, feels fine in the upper RPM (intermittent)


Possible causes:
-Trans speed sensor (often forgotten about)
-Coil pickup
-IAC (Mines the OLD type, metal end)
-Intake leak, vac leak
-Converter locking when it shouldn't (not likely)
-O2 sensor (not likely)
-injector, fuel pump (I need to check pressure)
-ECU connector (never cracked it and looked)


The hard part is, it's intermittent. Some days it's fine, some days not so much. It throws no codes or the CEL. Any tips on where to start? Car looks to not be equipped with an EGR setup, rules that out.

Also: Can someone explain the vac deal on the passengers side firewall? - The canister and valve.

 

[Monomer]

It's got to be vac related. It only seems to be a problem with lower vac levels (no throttle)


When updating the hoses the last time, the top of the evap canister top popped off. I suspect it finally went completely. I didnt replace the PCV elbow either, going to change that out.

 

[Monomer]

Update:

It's been a combination of issues.

-Wire from coil to cap is toast. Replacing it with a proper mopar.
-Hard plastic vac lines. Cracked when looking at them the wrong way. Tossed.
-Plug wires: the "better" set from advanced auto, junk. One was just pulling out of the cap.
-Car consumes coolant, afr changes with water temp, no good.

In the process of limping the car home I fear I may have washed down the rings and plugged the cat. It hasn't been a good month for me. KEEP UP WITH NORMAL MAINTENANCE....

 

[Monomer]

Not sure how you discovered this, but air/fuel ratio is DESIGNED to change with coolant temperature. The Coolant Temperature Sensor's input is used to determine richness of the mixture - richer when cold, leaning out when warmed up. Is there something drastically wrong with this, what data tells you this?

I phrased it wrong, you are correct. But currently theirs all kinds of air in the system, would this not cause afr's to be all over the place? The sensors want to see load, not hot air.


When I did the head-gasket I used a cortco (sp?) gasket, similar to a mc-cord. Used new bolts (stretch type) and torqued in sequence/steps to what was called out, plus the degrees. Head checked flat to less than .004 I didn't think to use the copper spray, as the gasket is a Teflon/graphite/slick to begin with. I think it has something to do with the surface finish of the head; I should have had a couple thou taken off.

If the gasket failed, it failed into a cylinder. No oil in the coolant, or milkshake. I plan on doing a compression test asap, along with new plugs/wire/cap/rotor (these were replaced 2 years ago now, my how time flies.) Belt was done at the same time as the head.

 

[Monomer]

You say you have air in the system. Have you double checked all of your hose clamps? I had a loose clamp on a heater hose on my 94 Spirit that was sucking air and it just about drove me nuts until I found it. Tightened it up and never had that problem again.

It burns coolant


The smell...

 

[Monomer]

Head gasket.

Still an ignition issue and a vac leak.


I'm going to top her off and get another week out of it before I tear it apart. Any recommendations on which parts to get? I usually go with non-felpro stuff from rockauto.

 

[Monomer]

Many of the AutoZone stores have a tester called the "Block Tester" in their Loan-A-Tool program. You basically put down enough $ to buy the unit (about $25) and then when you return it, you get your money back. With the "Block Tester" you have to buy the testing fluid which is $7.95 a shot. If the test is performed according to the instructions, you will know if you have a headgasket failure between a cylinder and a coolant passageway, however, there are some reports that state that fresh anti-freeze may show negative for exhaust gas contamination even when there is a small leak. The vehicle may have to be run daily for a week or so to create the anti-freeze contamination so the test kit will work to detect it.

Sometimes you can sniff the overflow container and detect the smell of exhaust gas. A compression test is not helpful on a small leak that just blows a stream of small bubbles. With a small leak, the loss of compression may be very small and almost impossible to detect over several cranking revolutions. A leakdown test also may not be conclusive. The usual 2.2, 2.5 headgasket failure starts with a very small leak. A blown gasket is more of a sudden rupture of the gasket material and that type of failure is easily detected by a compression test.

It's consuming to much to be a small leak. I feel it's around a gallon a week now, and was hardly noticeable months ago. This just started recently.




I'm going to start with a compression test.


As for which brand HG, I was told to use anything thats slick like the mccord. I was told to not even consider felpro, this is coming from a local chrysler guru. If it does need replacement: do I assemble dry (what I did the lasttime) or spray it down with copper/haylomar?

 

[Monomer]

Yes, a compression test will be done this weekend.


The gasket was not an MLS, it was a coated mccord style gasket. I do believe an MLS gasket is available, along with studs. The head and deck surface has to be pretty fine for them to take, this car wasn't all to pretty.


I did notice a small coolant leak in the lower pump hose going to the heater core, where a splice was put in. New molded hose on order. Hardly a drip under it, I suppose it may leak more with flow. The expansion tank also has seen better days, is there a source for these or am I installing a custom mt. dew container?

 

[Monomer]

Even better.


It's the coolant lines going to the TB that leak. I mean LEAK. Small puddle under the car now.

Still going to do a compression test, as it's quick. I think most of my issues were vac, ignition and cooling system. I'm straying away from HG due to no oil/coolant mix or over pressured lines. The smell could have been caused by the TB leaking down to the exhaust manifold. I never did see all to much white smoke from the back.

Ordering all the hoses from rockauto, seems to be cheap. Also getting all the parts or a tuneup.

 

[Monomer]

You can also get generic CRS bottles. The shape is just to get it to fit on the radiator; you can put the bottle anywhere, so long as its overflow inlet is slightly below the radiator cap (at least, that's how I would set it up, although I'm not sure it would matter when the cap opens under pressure. Check your local junkyard if you want OEM, it is one of those weirdo parts that nobody really ever needs

Thanks for the heads up, I have access to a tig at work so maybe I'll fab up a mount. It's ALWAYS empty when I add coolant. ALWAYS.


The intake coolant hose (steel one) was leaking, pretty bad. A compression fitting to a rather large barb fitting should work. I moved the clamp, as it was rather loose and the hose was more towards the end of the connection. Hopefully that help now. Is anyone against a small hole in the t-stat for burping? The bleeder on the head is stuck, and stripped.

 

[Monomer]

I'm in SE Michigan.



I think drilling a hole will be easier than finding a suitable hill.

 

[Monomer]

Went to go to work today.


Turn the key, nothing.


Tumbler's broken. Could this have anything to do with the rest of my issues?