'90 Talon N/A 2.0L 4G63 Manual

[rollin7s0n]

Car is a '90 Talon N/A 2.0L 4G63 Manual, with a '91-'94 ECU, with the pin swap having been performed.

Car has a range of problems, ranging from.. idle, startup, and acceleration.

The usual, however, I've done and tryed what the FSM advises to troubleshoot problems, and what I've researched and been told/advised on also.. And nothing's helping or fixing the problem.. Please, bare with me, and help me with this.

Thanks to anyone and everyone!

Notes..

Car has gotten, a replacement ecu, as stated above. New spark plug wires, new spark plugs, new fuel filter. It's also gotten a replacement Power Transistor Unit, a replacement Tacho Interface which is attached to the Coil Pack, a replacement Throttle Position Sensor, a replacement CAS sensor, 1 replacement Fuel Injector, new upper Fuel Injector o-rings, a new timing belt, a replacement aftermarket air filter, and a replacement radiator.

It's also gotten a replacement Throttle Body Gasket, in between the TB and the Intake Manifold. Car has also gotten new positive and negative battery connectors. The car has also gotten a rewire of the o2 sensor pigtail, coming from the harness, which the original, was torn up.

All vacuum lines that I can think of, have been clamped, all hoses I can think of have/are clamped. Tension on the Throttle Cable seems fine, tested the ISC and the TPS, and all 4 Fuel Injectors, and they are all in the range of the OHM's from the FSM.

I've installed an EGR blockoff plate, which the FSM says that idle might be bad, because of a leaking EGR Valve, but the blockoff plate didn't help, so now it's off. I've checked the TB plate, and it seems like it's closing/closed good, but doesn't look nearly perfect, and I can't figure how to adjust it, to make it look perfect. I loosen the TB Cable, but the plate doesn't move any further.

The MAF is a replacement from what came with the car, and the MAF I installed, is off of a '91 Galant GS Auto with the 2.0L 4G63 N/A.. And it works, was pulled from the Galant, which was running..

I've also tryed re-routing all the vacuum lines to the factory setup.. The car has also gotten a new battery.

The problem with the idle, is that it doesn't hold, and it also surges down. It doesn't hold on a cold startup at 1,500 RPM, for the idle warmup stage. It also doesn't hold in neutral. It also surges up sometimes, like it gets stuck or it surges quickly, then stops.

The idle also drops down after warmup, and it drops down after I reverse, and makes the car die, when I shift into neutral, and attempt to shift to 1st to start moving. The car always, also dies when I'm coming or rolling to a stop and put the car in neutral. The lights also dim at night, when the car idles down and dies.

The car also starts fine, but doesn't hold idle at startup, wether it be cold or warm start. It starts up, but doesn't hold idle and dies. The car will only start and stay on after it dies on the first start, only if you gas it for a few seconds. Also, when attempting to restart the car after it dies or in-general, I'm cranking the car, and I can feel/hear the cranking getting slower or dieing down.

Also, when reversing the car, it feels like it's not engaging or getting power, you kinda have to rev it a little higher, then it starts engaging and gets its power, and reverses smoother. Also, when shifting into 1st, and proceeding forward, the car needs a little higher rev, to feel/get the power, and accelerate faster. Feels like fuel or air is cutting or not sending/flowing. Same goes for 2nd gear, when you're shifting into it.

The idles dropping down, only seem to happen when the fans kick on.

Me and my friend have used a DataLogger on my car, and it appears that my ISC is reading up, when accessories or the fan is kicking on, or accessories are being used. But if I remember, it's also reading up, even when accessories and the fan is off. And the DataLogger was also reading that my timing jumps randomly at times, so does the idle..

Also, after I warmup, and I'm leaving my place, when I'm driving slowly, I hear a liquid noise inside the car. Sounds like when you shake or move a big gulp around, like the ice and liquid moving around. Also, the noise goes away after I've driven for awhile..

And then, the idle seems to stay when the fan kicks on sometimes also..

I'm lost, sorry for the huge block of texts, I'm just trying to be as detailed and informational as possible, so I can get this thing solved, because I'm truely loosing my mind and love for DSM's because of this..

 

[AnthonyP]

Have you inspected all the throttle body seals? It may be who of you to also open up the ecu and make sure it doesn't have any leaking caps.

 

[300hpbound]

I would agree with the leaking caps.

The stuttering and not holding idle still sounds like something fuel or air related for some reason. It would run rough if it was spark, or not start at all.

Your power issues sound like clutch problems to me. it may need a clutch or just a simple bleeding. There's a few items in between the pedal on the trans that could be worn out as well.

there's a scerw right next to the TPS on the throttle body called the BISS screw that takes care of small changes in how far open/closed the throttle plate is so I don't know if you have tried working with that either.

the "liquid" noise is probably just the antifreeze going through the heater pipes

If i'm wrong on any of this guys please feel free to correct

I'm sorry for all your problems, welcome to working on DSM's

 

[rollin7s0n]

Thanks for the quick replies. I actually haven't pulled the ECU yet, so I'll definitely give that a look over.

Also, about the BISS, I never really realized that it messed with the TB Plate, but that's good to know. All I knew was that it messed with the idle, to lower or higher it.

Also, regarding my BISS, I do notice, that it backs itself out, and doesn't stay in the position I moved it to, when I take a 2nd look at it, after I originally set it.

Any thoughts on why it's backing itself out? BISS O-ring?

The car just always dies now.. It'll drop idle in nuetral, and drop really low, then try to catch itself, then die. While it's catching itself, the lights flicker.. Could it be the alternator? I haven't tested it, but I'm not leaning towards the alternator.

 

[chaggard27]

So just to get a few things corrected the BISS doesn't actually move the TB plate it just let's in more air thus changing your air/fuel mixture and raising the idle. Also lights flickering is normal for a dying engine since it is loosing the 14 volts from the alternator. Sounds like either leaky caps or an air issue.

 

[rollin7s0n]

Some other things I forgot to add. Regarding the leaking caps, I tend to disagree, but I will look into 'em..

As far as something I forgot to mention, as far as the whole idle problem, where the idle will drop, then the car will die..

I've started giving the car some gas/gassing it, to hopefully keep the idle up and prevent it from dieing.. And with that, the e-brake is up.. (Trying to be as detailed as possible.)

Also.. I notice that when the idle drops, and I try to keep it with, with gassing the car a little, it seems like reaction time, or something isn't accurate.. Like, I'll rev it, and I know I'm pressing enough for the idle/gas/accelerator pedal to react, it doesn't react right away or on point.. It's late.

Same thing when I accelerate, there's like no power, or it feels like somethings not flowing, or it feels like somethings stuck or sticking, then after I ease off, everything's fine again with acceleration..

Another thing, is that when the car drops idle, and is about to die, and I rev it, if I don't catch it good enough, and it's about to die right that second, but I end up catching it, it's like it takes awhile for the rev to catch the idle, then for some reason, the idle raises to like 2,000 RPM, then drop, and starting surging up and down, and it'll be fine after that..

Also, regarding startup, and the car not holding idle, the car does start alright, but I gotta give it a little gas for it to stay on..

When the car is finally staying on, and warming up, it actually does hold idle, but not at 1,500 like it should.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)


This may help.

 

[syndr0me]

Just an idea, but you seemed to have mentioned everything but a compression check... who knows. Not to mention cheap and easy to do. Wouldn't hurt.