Shop Help

4GTuner

Help Support 4GTuner:

Joined
Dec 8, 2012
Messages
5
Location
Westminster, Maryland
Hello. I am new to this forum so I appologize if I have any newbie Q's or post in the wrong section a head of time.

Ok so here is the problem. I run and operatate a performance shop in Westminster, MD so I am very familiar in what to do and mechanically inclined, however I have never had a car so Frankenstein'd in my shop before. It's pieced together and has so many parts from other cars and so many things done to it from other people I don't really know where to start so I'll try from the beginning.

It's a 1991 3000GT VR4 with a completely rebuilt engine. That much I know is good. He took his car down to a performance shop where they stole most of the aftermarket parts off the car and replaced them with parts from other cars. Wires were cut and things were moved around and turbos replaced with bad ones from a WRX.

He took it to another shop in Laurel where they too stole off his car again the turbos replacing them with poorly modified and leaking 13g's (15g's were stolen) of which were replaced with another set of bad stock 9g's. More wires cut and alarm system stolen along with the turbo timer and gauges. Apexi NEO is untested at this point too but was told its ok.

My customer picked me up so we could get the car only to find out the shop reverse polaritied the guage wires and fried the fuel pump. They put in a used Walbro and the car started again. His car originally went into the shop for a problem with it spitting after 5k RPM's. They stole his AEM and installed an ecu from a Montero which was also stolen by the shop after that. So I'm not sure of the ecu that's in their now. The fuel injectors were also stolen and swapped with God knows what and it has an AeroTechnics adjustable FPR. It has a FMIC and a grandier manual boost controller. The vacuum lines instead of being capped at the TB they left lines on them and just installed a tri-splitter on it which joins all three together. He informed me he has also done a 6-speed conversion on it as well.

Getting the picture yet...it's a Frankenstein car. Everyone knows my shop and our work so everyone comes to me to fix their cars but this one has me stumped.

It still has the problem of at 5k it looses power and spits like a machine gun. While coming to a stop the engine will sit and idle at 2k for about 2-3 seconds and idle back down to 1100 RPM's. Now I'm thinking for that IACV or idle adjuster screw but that's all the way in. I know it has good fuel pressure and climbs 1psi per 1lbs of boost but still nothing shows. I'm not really concerned with the lightly smoking turbos but need to figure out why it's losing power. The car does occasional decided to just shut off. I let it sit for a few seconds and then she fires up again. Other times she won't do it at all. I have read on here that a speed sensor or cable or ecu can have the same effect but I do not want to parts swap this guys car. He has been through enough but this is definitely testing my skill to its max and I'm just clueless to what the problem could be. I'll try and post some pictures up in the next day or two.

So any ideas at this point would be appreciated. My only thought would be to start from scratch but I'm not quite sure where scratch is. There are too many things rigged on this guys car. Any opinions on whether or not just starting with fixing the known issues or jump right on the main issue of 5k fall out? My thoughts are to take the car back to stock fix all the little things and work back up again. However it's his money and I do not want to blankety go crazy with it. Any chance I could just figure out what the problem is, fix it and then do everything else later?

Take into account the 5k problem was there before he had all these problems with people stealing from his car and Frankensteining the hell out of it.

One more thing. Because he did a 6-speed conversion on it doesn't the ecu have to match that for idle and drivability or am I wrong? I know with nissans you have to change the IACV and the ecu when swapping from auto to manual because of idle problems but I know this isn't a Nissan either.

Thanks for the help and sorry for the long post.

I also forgot to mention the shop we picked the car up from said they had it on a dyno (5-hours worth...BS) but said the car was leaning out too. Not sure whether I should believe them or not but that's what they said. I am going to talk to my customer about installing a wideband first so we can figure out where the A/F ratios are.
 
good luck with this one boss, shes a biggie.
for your idle issues
i have a topic stickied in the evo 1-3 section about bad idle issues. I think the V6 will have a very similar system and the checks will apply.

you will have to start at the basics, Compression test- dry and wet. check cam and ignition timing. check the fuel pressure at idle and at 5k rpm...

then you can chuck a wideband o2 sensor in there to see if its rich or lean when its spitting, and work from there. you will probably need to put in another ecu and change injectors to stock or similar.
 
So I got a chance to speak with my customer a short while ago and this is what I came up with.

1.) I'll be making a list of the things needed to start all over from scratch.
2.) Labor wise I will be fixing the tedious things under the hood first to rule out any minor problem like fix the cluster mess in the engine bay by removing unnecessary vacuum lines, capping the ones that are just hanging there and cutting in new WG vacuum lines that are of equal length. The one WG turbo closest to the firewall has a vacuum hose about 1' long while the one closest to the front bumper is about 3.5' (maybe a bit longer then that) long. Yeah...I know. Someone actually did that.
3.) Testing the electronics for failure due to the sudden loss of spark (still can't figure out why)
4.) We are going to order in all new gauges including a Autometer wideband. All mechanical gauges. We are throwing the electronic gauges out. Very unreliable.

***I do need some ideas on a good modified ecu supplyer for plug and play action. My customer does not want to spend another $1k-$2k on a stand alone. (he had an AEM unit before). He wants something to just drop in and go.***

Pulled the ECU and not sure what it is. It's not the one that belongs in the car. On the back in black magic marker it says "WAS 1082 / NOW 1629". Not sure what that means.

Lastly on the 6-speed swap he had done a few years ago doesn't the ecu have to be reprogrammed for a 6-Speed? Does anyone know of a good drop in ecu or a company that makes a drop in for the VR4 with a 6-Speed swap and light mods with stage 3 tuning done already on a stock setup?
 
Ok I forgot to mention too that I took it out on a test drive and at 5k she started to drop boost. She would peak at 11-12psi and then fall to 7psi and lose all power. There was 1 stripped intake plenum bolt I am going to have to retap. I also noticed the WG lines are completely uneven. One is 3.5" long and the other side is 4'x3" long. Wow. What a mess.
 
Probably blowing spark above 5k rpm. Check heat range of spark pkugs and close the gap a bit more if need be.
Sometimes its best to get back to basics. I would return everything back to oem or near enough to it and replace the ecu and get the car running right first. That way you know its all ok and set the benchmark. Then with all the modified parts that were put aside, put them on and adjust tune and other add-ons accordingly. Start with a good base that you know works first because fuk knows how many hands have touched that car and how many little problems it has that can all add up together.
 
It seems to me that in this situation, starting from scratch (besides the above posts re:checking the mechanical basics) would be to install an aftermarket ECU.
I've seen electricians mess with automotive wiring in such a way that they should be stripped of their licence. Who knows what wires have been spliced into or o/c. What you're describing sounds like an electrical nightmare esp. if the car is running on an unknown ECU (whose to say the ECU isn't cutting fuel at 5k etc?) and rewiring the whole show might show up or fix half of your problems. Having said that, I drove a friend's 3000GT (same car) and it had the exact same 5k issue. I'm sorry to say but I don't know what he did to fix it or if he even did. I'd make sure you have the right injectors first, and if the other shop has run it lean for 5hrs, maybe put a borescope down into the cylinders to check for physical damage.

Btw, I'm sure nobody is bothered but you've posted in the E39A VR4 section. You might get more accurate help on this issue from a different website.
 
I just googled e39a vr4. I did not know about this type of car. My ignorance had me thinking a 3000gt vr4 were all the same starting from around 1991 and up. That actually looks like a pretty slick car. I like the boxy style and body lines. These E39A's are old school. I like em.
 
Hi,

I have a e39a and a 3000gt - both are good cars.

I have a ecu that you could use ( stock ) or I can point you in the correct direction for a ecu to fit.

On the 3si.org site, go to the australian section and you will get lots of help.

I would close the gap to 0.65mm and see how you go. The ECU is behind the stereo, get the numbers and the model of the injectors.

www.3sx.com
www.dynamicracing.com
www.supercarengineering.com
www.3si.org

this is all the info you need :D

Glen
 

Latest posts

Back
Top