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montyz81

Jim Wolf upgraded ECU questions (Jim Wolf Technology expert needed)

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I have an 81Zt now with a rebuilt 82Zt engine and 5 Speed recently installed. The car idles horribly and runs much better under load with some hesitation. I have been trying to troubleshoot the lumpy idle and am starting to think I might have some corrosion in the wiring. I have checked requisite sensors included in the idle control circuit and so far they all check out. I have run a smoke test and the vacuum checks out. I can pull the plug off the CHTS and the idle speed will pick up immediately and the engine will run smooth (just installed a brand new CHTS). The car has been running with a Jim Wolf upgraded computer since I put the new engine in. Just for giggles, I put the 81 computer back in and the car ran much better, but is still hard to start and runs a little lumpy at cold idle. So this leads me to believe that part of my idle problem is with the upgraded ECU. I thought, well I will run with the 81 ECU, but that has mapping for the 81t automatic transmission. I can deal with that, but that computer also has a problem where it will just cut out and shut the engine down. I am sort of stuck in troubleshooting because I am not sure if the lumpy issue is due to the upgrades in the 82 ECU as well as something faulty in the 81 ECU. My question is, does anyone know if the Jim Wolf technology upgraded ECU now expects other engine modifications in order for it to work properly. I have no history on the upgrades as I got this out of a parts car I bought a long time ago. I never bothered to ask the guy about it because I actually bought the car for the transmission and some other interior parts. I had to do the 82 upgrade because my 81 engine was pretty much toast after 200k miles. I am learning about how the fuel injection works, so forgive me if I misstated something. I have been using the FSM to troubleshoot as much as my knowledge and tools will allow (So far that has just been an ohm meter). I would like to upgrade the ignition system, but I feel like I need to solve this idle problem first in order to make sure I have a good working EFI system before upgrading it. If anyone can help me troubleshoot more (especially if your are local to NH), I would be greatly appreciative. I have plenty of beer here if someone is local :-)

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SO I found out that the dropping resistor block on the 1981 Turbo is not needed on the 1982. The car runs much better and has power mostly through the power ban. I am still having a hard time starting the car. I have a new fuel pump on the car, but now I am suspecting it is either Fuel Pressure Regulator or Fuel Dampener. Can someone tell me how to test each of these? Would I have to test the fuel pressure before and after the FPR? It looks difficult to do after the FPR. 

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As far as I recall, the JWT ECU throws quite a bit of fuel at the engine, it would also depend on which unit you purchased as they are "optimized" for certain setups, granted as stated they usually over fuel to probably stay on the safe side.

 

Checking your fuel pressure would be pretty important along with timing. Fuel pressure should be checked before the FPR, could be done with just a manual gauge. 

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I have a JWT set up. Yes it never starts on the first try cold. you do need the dropping resistors for the  low impedance injectors. The BOV needs to recirculate and not go into the atmosphere. There needs to be at least 6"  on either side of the maf so pipe in front of the turbo and before the air filter. It does run rich but then there's not really much tuning. I run about a 14psi and it's a lot of fun 

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On 8/14/2018 at 9:06 PM, malibud said:

I have a JWT set up. Yes it never starts on the first try cold. you do need the dropping resistors for the  low impedance injectors. The BOV needs to recirculate and not go into the atmosphere. There needs to be at least 6"  on either side of the maf so pipe in front of the turbo and before the air filter. It does run rich but then there's not really much tuning. I run about a 14psi and it's a lot of fun 

I did call JWT and they told me to take out the dropping resistor. I did and it is now running much better.  Sorry for my ignorance, but what is BOV?

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