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1G New to 4 cylinders and fuel Injection

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Meteshjj

Probationary Member
26
1
Sep 1, 2015
Bozeman, Montana
I have always loved DSM cars. My friend had a 91 Laser that was faster than every car we had (except my Cummins). Last week, I decided to buy one. So, for $500 I picked up an untouched, second-owner 1992 Eagle Talon TSi AWD w/ LSD. Aside from the K&N air filter, everything on this car is bone-stock. However, it has been sitting for 4 years.

I've gotten old (Read: unused) cars before, so I did all of the normal stuff to get it going again: Fuel pump, filters all around, cleaner sprayed through all of the hoses, etc. It only had about a gallon of fuel left in the tank, so I diluted it with 11 gallons of premium and some fuel system cleaner. This got the car to fire off of starting fluid, but nothing else.

At this point, I figured the injectors were probably toast, so for $40 I bought some black top 450cc injectors from a friend who has a 2G Eclipse. This got it to run on its own (hooray!). It wouldn't rev up past 4k, though. The same friend suggested that it could be the ECU. Being that he is a Mitsubishi mechanic, I pulled my ECU and noticed rust on the back side. He cleaned off the ECU and replaced the caps with solid-state caps and I put it back in.

Now, the car won't run past 4k unless you add fuel straight to the intake (taking place in the form of carb cleaner). Once you do that, it will rev all the way to redline until it runs out of that fuel. Normally, I'd suspect it being lean, but the tail pipe has a lot of black smoke coming from it. When I pulled the plugs, they were incredibly fouled. Cleaning them does nothing, and they foul again within minutes.

So, my two questions are: will bad fuel do that to a turbo DSM (I've never had problems with it this bad, but those cars were all v8's)? Is it possible the ECU is still dead? Any help would be appreciated. I have a fuel pressure gauge, A/F gauge, and a better boost gauge on the way as we speak, so I'll know more when they get here.
 
You need a method to log the car. If its dumping fuel in and fouling plugs the coolant temp sensor is a common culprit. Yes ecu could still be the culprit. So could fuel pump. Last car I had ate two pumps from the dirty tank. I shouldve dropped the tank and had it cleaned. Coolant temp is more likely. Gauge is not a good sign. Ecu uses its own sensor separate from the gauge. If its bad it reads cold and the ecu will dump fuel thinking its cold.
 
How long does it take to warm these up? It will generally foul the plugs even after a cold startup and only running for a few minutes. Would that still be coolant temp sensor?

I also forgot to mention that I tried to check the CEL with a light, but I get no signal from it at all. I figured it would be a wiring issue, but now that I think about it, the ECU could just be bad. If the ECU is dead, would it be better to get a used one, refurbished one, or just go straight for the ECMLink kit?
 
I changed the CTS (yet another sensor that looked original to the car), but I have the same issue. However, I did discover something by complete accident. If you leave the MAF unplugged (oops), there is absolutely no change aside from a little better idle. I hear these 1G MAFs are prone to failure. Is there a good way to test for it?
 
If most of your symptoms disappear when you unplug the maf either the maf is bad or you have a huge boost leak. Unplugging the maf puts the car into basically a very bootleg speed density type of situation so if your mods match the settings in the ecu you will end up with a car that runs like crap with the maf plugged in and decent with it unplugged. Without a way to log you won't be able to see what it is reading which is how you would normally be able to see if it is bad.
 
Its your maf period. If you unplug it, it should run, sound, and idle horribly. Like one of the first things i learned about these. Check the honeycombs, clean it with some maft cleaner spray. Some will say dont use spray on it but i have. It does not hurt anything. Also as suggested do a boost leak test. I am sure you have a few. If it still runs crappy replace the maf.
 
I changed the CTS (yet another sensor that looked original to the car), but I have the same issue. However, I did discover something by complete accident. If you leave the MAF unplugged (oops), there is absolutely no change aside from a little better idle. I hear these 1G MAFs are prone to failure. Is there a good way to test for it?
Well, it doesn't get better with the MAF unplugged. It stays the same. Nothing changes. The idle is a little better with the MAF plugged in, but that's it.

Its your maf period. If you unplug it, it should run, sound, and idle horribly. Like one of the first things i learned about these. Check the honeycombs, clean it with some maft cleaner spray. Some will say dont use spray on it but i have. It does not hurt anything. Also as suggested do a boost leak test. I am sure you have a few. If it still runs crappy replace the maf.

I've replaced all of the vacuum and intercooler lines, so I'm fairly confident I don't have a boost leak unless one of the manifold gaskets has died. Is that a fairly common failure?

I have a 2g MAF and a GM MAF sitting on the shelf waiting to go in. I eventually want to setup a blowthrough GM MAF, but until then, what's the best way to get the 2G MAF connected to the stock intake pipe? I still have that accordion thing, but the 2G MAF didn't come with any piping.
 
2f maf in a 1g won't work without someway to compensate for airflow. Boost leak are a common culprit to a lot of problems. It wouldn't hurt to check. Intercoooler pipes and joints, vacuum hoses, throttle body gaskets, TB shaft seals, IM gasket, fuel Inj seals are some common places for a leak
 
Start with a boost leak, make sure there is no leak first. Once completely ruled out I would suggest begin by swapping out the maf. Ask a friend to borrow theirs for a quick test, or buy a used one should be very cheap. Also have you changed your fuel filter? Doing all of that cleaning may clog your filter, its cheap i'd suggest to change it. If that doesn't do the trick find a cheap used ecu that you could swap or even borrow one for testing see if that does it. My scenareo is that the car is thinking it has a certain amount of air and tries to compensate with fuel, except that air is not getting into your engine, it may be from a bad maf reading or a leak in the system.GL!
 
Building the tool:
www.youtube.com/watch?v=u3Kqh52PC6Q
Using the tool:
www.youtube.com/watch?v=fdjadhUP1u4

I HIGHLY recommend searching through his videos and find stuff that will interest you. All of his videos are extremely helpful. Don't let any of the hyundai elantra videos throw you off, treat it like a DSM because he addresses DSMs (it's drivetrain swapped). He gives torque specs and part numbers for 1 and 2G DSMs so if you're ever lost, he has a detailed video explaining your problem.
 
A friend of mine had a 2G MAF intake and an extra pigtail, so I hooked up a a 2G MAF to it. The timing was off and the BISS was not set right. After fixing all of these problems. It ran great. The idle came up, the turbo spooled, the BOV worked like it should, and the car would rev all the way up redline.

I put my 1G MAF back in (to make sure the timing and BISS weren't the sole causes), and everything went to pot again. My MAF is dead, so now I'm looking for the piping to go to 2G. I will update everyone here with the results.
 
for $40 I bought some black top 450cc injectors from a friend who has a 2G Eclipse.

Are you saying you installed OEM 2g fuel injectors into a 1g car, with no tuning solution?



P.S. Don't just throw parts and money at the car, diagnose for a fact what is wrong, then replace/repair/upgrade. Also www.vfaq.com is a good source for tutorials, and old school mods.
 
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You arent listening. You cant just go in changing stuff without knowing what it does. The very title of this thread says it all. The 2g maf is calibrated for a 2g ecu and code. Just because the car ran better does not mean you found your solution. If you want to blow up the car continue on the path youre on. A 2g maf will run a minimum of 20% lean in a 1g car unless you have a tuning solution. Right now the 1g ecu is desperately trying to add fuel based on o2 sensor feedback, however the range to add isnt big enough in the code. Furthermore at wot the ecu doesnt use o2 sensor feedback. Wanna guess what happens when youre 20% lean at wot at full boost? It seems you did find your problem as the maf but you should solve that problem with a new maf or a tuning solution for the 2g maf.
 
You could even still have a coolant temp sensor issue but you sort of over corrected for it with a 2g maf. Did you check the output of the old sensor before replacing it? If the problem were a harness a new sensor wouldnt solve the problem either. there are also multiple Coolant sensors but only one feeds the ecu. Did you replace that one?
 
Ripper the 1g blue top and 2g black top turbo injectors are all 450cc. He will need a tuning solution using a 2g mas and 450cc injectors that's gonna run way way lean. OP the 2g mas has a different signal going to the ecu allowing more airflow. With that extra airflow it leans a 1g car out. Some have had luck doing a 2g mas and 550cc injectors at the same time. I would not recommend 2gmas/550's without some sort of tuning solution and a wideband o2. My 2gmas/550cc ran really lean at idle and cruise.
 
I replaced the ECU CTS. The resistance was not in spec according to the FSM, and it was $5.

Both the 1g injectors and the 2g ones I put in are 450cc injectors, so I'm not flowing any more fuel.

The 1G MAF is dead. Period. I don't want to spend $200 on another 1G MAF if I know I will eventually be replacing it.

Right now, I'm aiming for something that will run. Once I'm confident that the car has some life in it, I will spend the money on ECMLink, but I don't feel like dropping $700 on a car that's going to die. I didn't even pay that much for the car.

What I've been told is that the 2G signal has a higher frequency that sends more data than the 1G ECU can handle.

This car won't be anywhere near WOT until I replace the ECU. I am just working on making sure the car is worth it.
 
You are still 20 percent off at any throttle position. You simply can't run a 2g maf by itself. You either app k y a tuning solution or get another maf. You should be able to get a used 1g maf for nearly nothing.
 
I'm aware of that. Like I said, I don't want to spend $700 on an ECU until I know the car is worth it. Once the 2G MAF is in, I can idle well enough to test other parts of the engine. I can get it to operating temperature, I can live test sensors, and I can install Electrical components that I will need later.

I know it will be running lean. That's why I won't be streeting it. Before this, I could very well have had a compression leak, bent valves, bad coils, dead clutch, or 1000 other issues. Until I can afford the ECU, I can at least do some diagnosis on the other systems with the car idling.

I will be putting a tuneable ECU in it. It won't be run without one, but for now, I'm making sure the investment is worth it.

EDIT: is there a way to temporarily make the 2G MAF more restrictive to run these tests more safely? It would richen thing a bit to have less air, no?
 
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No. A 2g mass doesn't run a bypass tube like a 1g mas does. It's all counted. Honestly I don't understand why you wouldn't bolt in a 1g mas to do your testing. If I had one I'd give it to you.
 
I'd be more than happy to put a 1G MAF in there to fix the rest of it, but I can't find one I'd trust for a reasonable cost. There doesn't seem to be a big 1G DSM community where I'm from. You see 2G's and Evo's everywhere, but the 1G's usually get junked. Plus, if it does have 4WD/AWD, it isn't worth anything to people around here.
 
Contact Millerimportparts (google it) or Stangmurdera on here. (same people) He specializes in DSM's and might have one and his prices are very reasonable.
Don't run it with a 2g maf unless at bare minimum you put 550's or evo 560's injectors in (and long term you would still want/need to tune). The car really won't be worth putting money into when catastrophic engine failure happens. Evo injectors are dirt cheap too.
 
No. A 2g mass doesn't run a bypass tube like a 1g mas does. It's all counted. Honestly I don't understand why you wouldn't bolt in a 1g mas to do your testing. If I had one I'd give it to you.

That's not true. A 2G MAF has the center chamber where the vortex sensor is. A left and right chamber, and a lower chamber where the adjustment screw is.
 
Well I stand corrected. It's been years since I stared down the throat of a 2g mas. For idling purposes only you might be able to block the bypass tube.
 
Dude, where are you shopping for parts, Autozone? $700 for an ECU and $200 for a MAF? I think the last known good MAF I sold here was for like $40 bucks shipped with the airbox included. I've seen ECUs go for a bit over $100. You should be able to get both for under $200.

Step 1, get the proper MAF on the car. You're going to have a horrible time troubleshooting with a 2G MAF on the car. It's a complete waste of time, IMO. Pick up a used known good 1G MAF from somebody in the classifieds, and then do your testing. Quit spending time trying to figure out ways to make the wrong MAF work on the car. As the others have already told you, without a tuning solution, it will never work properly.

Step 2, inspect your ECU. Most of the time, you can identify damage visually, or by smell. No sense in throwing parts at the car unless you know they are bad. Pop out the ECU, and open the case. After you do that, read through this and inspect: https://www.ecmtuning.com/wiki/ecurepairhome . If you suspect damage, you can send it to the guys at ECMlink for inspection and repair. Typically, a repair is cheaper than a used ECU.

Step 3, you should verify the car is mechanically sound before you start troubleshooting all this electrical stuff. You're working backwards, IMO. Check mechanical timing, compression, fuel pressure, spark, etc. These are basic and easy things to check, and can all be done without the car even running. Without these, the car will never run right, whether the MAF and ECU are good or not.
 
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