ECMlink Car runs rough after warmed up

[TrystanGST]

So I have an interesting problem. After being down for a month, I finally got the new head put back in and have been driving around. The cars idles around 950, which is fine since Link is set to 900. For the first 5-10 minutes depending on driving style, the car runs fine. But after it gets good and warmed up, it starts misbehaving. The best way to describe it is it feels like timing is off. The engine goes from a smooth idle to a constant popping. The more gas you give it, the harder it studders. If you lift off the gas, it smoothes out until you're at idle. It only does this when it's warm. I checked timing cold and hot, and in both cases the marks line up.

 

[DeadlyScone]

Silly question but, when was the last time you checked/changed your spark plugs? And are they coppers? Might be a good idea to check your gap and the integrity of the plug itself.

 

[stuckwithgsx]

What plugs are you running? Try a colder plug possibly?

 

[DeadlyScone]

What plugs are you running? Try a colder plug possibly?

+1 on that idea also.

 

[TrystanGST]

Hrm. Good idea. The plugs are new (a week old), and I gapped them to .025. They are Bosch though (autozone didn't have NGK...). I'll pull them this afternoon and see how the plugs look.

 

[DeadlyScone]

Hrm. Good idea. The plugs are new (a week old), and I gapped them to .025. They are Bosch though (autozone didn't have NGK...). I'll pull them this afternoon and see how the plugs look.

Go to NAPA, they have them there like 1.99 a plug or some cheap price like that. Stock # 5534 or just ask by the name

Make sure they are COPPER just in-case you didn't know.

 

[TrystanGST]

Will do. BPR 6 or 7? And is the .025 gap too tight?

 

[DeadlyScone]

If you don't run high boost 18psi+ on a stock or lightly modified setup just stick to .028 +/- .002 on 7's, for all else its up to you. here is an article if you want to read it and decide for yourself.

BEEF

 

[herms99gst]

Your timings not off bc you wouldknow as soon as you started the vehicle. If plugs don't solve it id look at your iac and throttle body. Might be a little gumed up. A dirty mas or a failing tps could also be the culprit. If it ran fine before i would also look for a vaccum leak of some sort. Make sure the O rings around the injectors are sealing and around your tb as well. But it honestly sounds like a dirty throttle body. Use the correct cleaner for the mas. Regular maf cleaner is to abrassive and brake cleaners a no no. Use a cleaner that is for electrical parts only and remove the maf when you clean it as well as the tb. Hope this helps

 

[TrystanGST]

I'll hit NAPA after work and try the NGKs. I'm still waiting on a BLT and I'm sure the throttle body could use some cleaning.

 

[DeadlyScone]

waiting? You didn't make one?

 

[TrystanGST]

Lol well I was going to, but I couldn't find the NPT fittings at Autozone, and it cost $26 shipped vs probably $30 to make my own. Yeah, I'm lazy in this regard. I've been working on this thing for almost a month before I got it to turn over again. I just want to drive it.

 

[DeadlyScone]

Gauge - $2 (O'Rielly)
Fuel Line $2 (O'Rielly)
End Cap $3 (Home Depot)
Brass Fitting $1.50 (Plumbing Place)
Rubber coupling - $4.50 (Plumbing Place)
Valve things - $5 (O'Rielly)
Clamps - $1.50 (O'Rielly)

Total = $ around $20 pretty much.

----------------------------------

Was fun to make and nothing feels more satisfying than something you make that works Where did you order yours from?

 

[TrystanGST]

Yeah, true. Ah well, If these plugs are the silver bullet I'll deal with a few vacuum leaks until the tester shows.

BLT: Boostpro.net : Products - Boost Leak Testers

 

[TrystanGST]

Well the BPR6 plugs gapped to .028 seemed to have solved that problem. The Bosch plugs looked like a coal miner after 100 miles. Ugh.

There's a new problem though. There's some serious hesitation on the throttle. I can boost thru first, shift to second, and it's a second or so before the car responds. If I go under the hood and move the throttle plate by hand, there is no hesitation.

 

[94allwheeldsm]

I have had great luck with the E3's lately

 

[herms99gst]

Did you check the throttle linkage?

 

[DeadlyScone]

Could be a bad vacuum leak.

As far as your plugs read this

Soft, black, sooty, dry-looking deposits indicate a rich air fuel mixture, weak ignition or wrong heat range spark plug (too cold). These carbon-based deposits are conductive, much like oil fouling, and will allow the voltage coming out of the center electrode of the spark plug to track down the core nose rather than jumping the gap. This will result in an engine misfire and further aggravate the carbon fouled condition. Check for correct plug heat range. On fuel injected engines, check for sticking injectors, malfunctioning cold start valves and/or circuits. Also check for correct fuel pressure specifications. On computer controlled vehicles, the "limp home" computer mode will always result in a rich condition. Therefore, it is imperative that you check the operation and condition of the on-board computer system. On carbureted vehicles, check choke and choke pulloff, high float level, and needle and seat condition. On all engines, severe vacuum leaks can decrease manifold vacuum, resulting in a rich condition. Weak and/or damaged secondary ignition systems will fail to spark across the gap lowering combustion chamber temperatures and promoting carbon deposits. This condition could also result from continuous low speed driving or poor cylinder compression.

 

[TrystanGST]

I do need to check the throttle - the idle RPM has gone from 950 to almost 1400. And there is definitely a vacuum leak. It's amazing how as soon as one problem is solved two more show up.

 

[DeadlyScone]

Almost sounds like a bad TPS, test it eith the following for 95-98 2.0l dohc

Ignition off and remove the tps sensor.(use a marker and mark in 2 spots where the sensor was offset to)

^
[1234]

A. Test the resistance with an ohmmeter accross pin 1 and 4 (the very left and right pins on the sensor)
Normal resistance should be 3500-6500 ohms(3.5-6.5 Kohm)

B.test across 2 and 4 now, slowly operate the throttle from idle to wide open; the resistance should change evenly and proportionatly to the throttle movement.

 

[Moy]

Sounds like a vacuum leak, pressure test the intake system and possibly smoke the system when the engine is warm, since that's when you're having your issue. Since you just changed the head, it's possible that a gasket ruptured, or bolts are under-tightened, etc.
When the engine is cold, the metal contracts and makes the gasket seals tight, but as the engine warms up the metals expand and expose a leak.

If it were a sparking issue, it should be more obvious when cold, as the PCM dumps more fuel to speed up warming of the coolant and 02 sensor to get the PCM into closed loop. More fuel = stronger spark needed to ignite the richer AFR's.

 

[TrystanGST]

So the hesitation issue was an unplugged MAF. Doh. Found it when Link showed the IAT as -71.

However, the original problem is back. I grabbed a few Link captures of the car right after the problem appeared. The car throws a random misfire DTC right as the problem starts.

The second time it happened, I shut the car off for five minutes and was able to drive fifteen minutes back home without the issue reappearing.

 

[Moy]

What format is that in? I've never seen an "elg" format before

 

[TrystanGST]

It's the format ECMLink saves its logs in.

As for the problem - I did some sniffing around on Tuners after posting this, and came across two situations that can cause the 0300 DTC, and both of them apply to me.

The first is a 1G CAS in a 2G. Something about sensors and phantom knock.
The second had to do with imbalances and vibrations. Having put in prothane mounts all around and done the BSE, I certainly have more vibrations going around.

The apparent solution to both of these is to disable the random misfire DTC in Link. I shall be trying that today and seeing if it helps.

 

[DeadlyScone]

It's the format ECMLink saves its logs in.

As for the problem - I did some sniffing around on Tuners after posting this, and came across two situations that can cause the 0300 DTC, and both of them apply to me.

The first is a 1G CAS in a 2G. Something about sensors and phantom knock.
The second had to do with imbalances and vibrations. Having put in prothane mounts all around and done the BSE, I certainly have more vibrations going around.

The apparent solution to both of these is to disable the random misfire DTC in Link. I shall be trying that today and seeing if it helps.

Band-aids don't fix problems unfortunatly.