Well my brother got his 87 gn running from a fresh rebuild. He has a high blm problem 160+ at idle. It will start up perfect and come down to a nice idle then after 10-15 seconds idle slowly drops and it just dies. we set the throttle stop/iac and tps to specs. His setup is 70mm Kenne Bell TB/plenum with RJC powerplate, PTE fmic, GT6133 with RJC boost controller, 60lb mototrons, extender extreme, translator/Ls1 3.5" maf with all 4 switches set to on per the extender extreme manual and both knobs set to 0, he still has the EGR valve setup on with new gasket installed, later design ATR SS headers running one donut gasket per flange even though SET performance gave him 4 when he ordered a set, and 3" thdp. It runs decent on boost, we took it around the block and it drives great while moving but as soon as you come to a stop sign for a couple of seconds he has to throw it in nuetral or power brake it so it wont die. Also it runs goos but it seems that it is not pulling to its potential under boost even though at 14LBS he got 0.0 Knock which is good. I would like him to solve this issue has has been working on for the last past 2 weeks since he broke the car in. Any ideas
87 GN fresh rebuild problems high blms flooding out
- Thread starter Stage 5
- Start date
Welcome!
By registering with us, you'll be able to discuss, share and private message with other members of our community.
You may have a vacuum or exhaust leak somewhere. I would double check everything. PCV,EVAP,check valves,O2 sensor,EGR and so forth. I had the same problem. I have several problems, bad alternator (11V), bad o2 connection (connector not latching) and my TP box needs to repaired. I can't say I have it fixed but I am getting closer.
You may have a vacuum or exhaust leak somewhere. I would double check everything. PCV,EVAP,check valves,O2 sensor,EGR and so forth. I had the same problem. I have several problems, bad alternator (11V), bad o2 connection (connector not latching) and my TP box needs to be repaired. I can't say I have it fixed but I am getting closer.
Thats not flooding out. If it were flooding out, the blms would drop to 90 and stop...thats where its pegged on the bottom. 160 is where it pegs at the top. The BLM is fueling correction. With Fords its called fuel trim. So if the number is dropping, that means the computer is sensing a rich condition and pulling out fuel to compensate. If its going up, that means the computer is seeing a lean condition, and is adding fuel to compensate. If its hitting 160, then there is a major lean issue, OR, the computer thinks its lean when it may not be. The latter would be an 02 sensor not working or a bad MAF...or the reading is being interpreted incorrectly by the translator (incorrect settings) First, warm the motor up completely and let it idle...wait till the little led stops blinking. That means you're in closed loop, where all the sensors are active and communicating with the comp. What is the AF reading...not air/fuel...AF on the scanmaster is MAF reading. Write down the idle number, then bring the rpms up to 3000 or so, and write down that number. That will help us see if the MAF is bad. Without shutting it down, go over to CC's...Its the O2 crosscounts. That will tell you how active the o2 sensor is, or if its active at all. It should cycle from 0 to 255 within 90 seconds and itll keep cycling. Do the same and write down the idle number and rev it to 3000, hold it stead and see what it does. Do the same procedure with BLM's. Also write all the other numbers down and post them. I think the translator may be set wrong and/or you may have massive vacuum leaks. There may be an incompatibility between the chip and the injectors as well.
Also make sure that anytime you make a change to the translator switches, unplug the computer's orange power wire for a few minutes to clear any memory thats been stored while it was trying to compensate for a problem. If you dont reset the computer every time, you'll keep running around in circles and not figuring out the issue. Mine had a 3.5" LS1 MAF, but it wanted the translator set to 3" MAF. If I switched it to 3" MAF though, the problem wouldnt go away..it would just get more weird. But if I erased the computers memory while changing the translator settings, then suddenly the problem would clear up.
post all those readings up, and make sure to warm the motor up every time and wait for the system to go into closed loop. Otherwise the readings are all bogus.
Also make sure that anytime you make a change to the translator switches, unplug the computer's orange power wire for a few minutes to clear any memory thats been stored while it was trying to compensate for a problem. If you dont reset the computer every time, you'll keep running around in circles and not figuring out the issue. Mine had a 3.5" LS1 MAF, but it wanted the translator set to 3" MAF. If I switched it to 3" MAF though, the problem wouldnt go away..it would just get more weird. But if I erased the computers memory while changing the translator settings, then suddenly the problem would clear up.
post all those readings up, and make sure to warm the motor up every time and wait for the system to go into closed loop. Otherwise the readings are all bogus.
The switches are ALL on via Extender Extreme instructions.
While I was with him driving the blms when he was on the gas were 128 most of the time. When he would back off the gas they would jump back to 160.
The cc were cycling really qucik/normal while he was driving so they were good.
When hes at idle its in open loop all the time if I recalled and didnt idle more than 20 seconds before the idle turned to crap
AF= 2-3 at idle somewhere one or the other .
We checked all vacuum routes and didnt to find any leaks. Brand new silicone hose.
He will try my LS1 sensor or the one off his 04 GTO to eliminate the maf then I will lend him my translator to troubleshoot that part.
I know a lot and this has got me stumped
, more likley the switches in the trans. or the maf. We will switch to my good working ones tonight.
fp=45 line off
no trouble codes
Thanks for all you guys time.
Michael
Well, you guys wont believe this. We fixed it so far, so we think. We disconnected the ecm wire and set the translator to (on on on off) we started it and it sounded like total **** so we knew the first settings of all on were correct, so we disconnected the ecm wire again and set them back to all on. Then I got a pad and pen to write down all the settings and we went around the block. By the time we got a mile away and the car was totally warmed up we both noticed that it was not trying to die on us at stop signs, so I scrolled to bl and it was at a solid 126-127 would not come above 130. I didnt even write down the numbers as it was very evident that the problem was gone. We get back to the house and let it idle for 3 minutes and it just purred like a kitten. I think the problem started after we broke the car in we adjusted his throttlebody stop because it was all the way out, and did the tps and iac also, it sounds stupid but we never did re-set the ecm after those changes were made. Now he needs to take care of that tranny to hold up to the extra power.
Similar threads
