DSM WISEMEN PLEASE! Im sick of not running right. PLEASE HELP

[rabenne]

I have had a problem with my car for a while now, and nothing I have tried has fixed it.


UPDATES in profile
Mods: 6 bolt, 1g rods 2g pistons, walbro 255 rewired, aeromotive fpr (stock pressure), RC 550's, turbonetics t3/t4 50 trim, turbonetics exhaust manifold, victory performance garrett o2, megan downpipe, 2.5" charge piping, large custom fmic, dejon tool intake pipe, ngk plug wires, ngk bpr-7es brand new, tial 35 external wastegate, zeitronix zt-2 with pocketlogger zt, apexi afc 2

Symptoms: Car bucks and misses hard at full boost and heavy throttle... Under lower throttle around 9 or less psi the car runs like a top... But as soon as I go past about 60% throttle with full boost the car lunges and jerks. This ranges from a small studder to a large jerk where the TIRES LOCK UP for a brief part of second, and as I let off the gas, it goes back to normal

Done so far:
New ngk plugs
tested coil pack, primary and secondary resistances, both in spec.
boost leak test, held to 20 psi great
checked plug wires for burnt ends, only 5000 miles old....
checked to make sure all connectors were tight
tps, cas, maf, injectors, coil pack, etc.
cried

IM ONLY RUNNING 12 PSI right now off the wastegate spring.... It still happens around 12 psi... . and hate that I cant get this thing running right. I can feel the potential of the car, but not anywhere near what it wants to do. I want my boost back... booo please help!

 

[Nanan]

The symptom is fuel cut. Why you are getting fuelcut could be many things such as a bad mas, boost leaks, or a bad ecu.

I would start with boost leaks, find a faq on it in the tech section and follow instructions.

Bad mas, test resistances per faq on that.

Bad ecu, umm not so likely, the 2g ecu were built a bit better then the 1g and are not prone to having the capacitors craping all over the circuit board. But shorts happen and stuff can still get cooked, if the previous two turn up nothing then try another ecu.


I assume you did the wire swap or some other method of getting the spark signal inverted? This will cause missfires but nothing so drastic as bucking, it just wouldnt run for crap.

 

[rabenne]

I just did a boost leak test, so Im almost positive thats not it.

As for the ECU, I would like to try one without buying one, but no body wants to help me out. I would even pay a deposit guarantee that it would be returned.

And for the MAF, I couldnt find any faqs on testing the maf, please let me know where to find it. maybe i suck at searching

 

[Nanan]

I am not sure where I saw the faq on testing of a MAS but it was either on this site or DSMTalk, I post on both boards.

The truth is that the 95' ecu are getting a bit rare, people are not so willing to loan them out for fear of it getting damaged by shorts or missuse.

Btw, when did this bucking thing start? Did it always do it, just after the 6 bolt swap, did you do the swap or did someone else?

The 50 trim T3/4 does flow allot more air then say a T25 or 16g so getting fuel cut at lower psi isnt a very big streach. Fuel cut is based on mitsu's crazy use of the karman style mas that runs a set range of hz = voltage differential, there is an inversion point in the 1800(?) range that tends to be the critical point on some cars but not all. If it turns out that this is the case you could get a chip burnt that will raise the fuel cut point to something beyond a problem stage.

Umm the SAFC2 has the ability to alter the hz range that the ecu sees by cutting the number in half or what ever... This could be something else for you to check out.

 

[rabenne]

Is the eprom the only one I can run? I know nothing about ecu copatibility. I am willing to pay a deposit of $125.00 with $100 to be returned when the ecu gets back.

If not, SELL ME ONE, if it still doesnt work ill sell it someone else... thanks

Will

 

[LT1andDSM]

What is your logger saying when it happens??

 

[rabenne]

The wideband says afr is around 11:1 at wot, the timing is pretty flat, nothing stand out to me. My tps has been checked in two places, afc and logger. what types of things should I look for that might cause my symptoms... thanks

 

[Nanan]

I'd say look for unusual dips in timing, tps position, O2 readings etc. If your tps is going then it can think that the tps is at 0% when its really at 70% or what ever.

 

[rabenne]

Well this may seem stupid to many of you, but I just picked up the best purchase since I bought my car. I was thinking about buying an eprom to throw in just to rule out a bad ecu... I searched on ebay... first result was the deal of the century. Included is an eprom ecu, socketed by dsmlink. It also includes the dsmlink software, and cable for a 2g. This for an incredable $615 shipped. If its not a bad ecu, I plan to sell my "highly valuable" eprom. that should get me about $200 in the classifieds. I also plan to sell my safc-2 and datalogging palm package, so another $225-250. After selling those two items I will have paid about $165 for dsmlink. I already have a perfect old laptop, and it comes plug and play.

Back to the tps, I havent seen any weird jumps or anything on the tps, and the pocketlogger zt, obd-2 logger, and my afc are pretty consistant to eachother. If there are any test procedure for this please hook me up with a link! haha

thanks

will

ebay link:

http://cgi.ebay.com/ebaymotors/ws/e...d=1,1&item=8068343673&sspagename=STRK:MEWN:IT

 

[GVR4592]

Post some datalogs. It might help more than you think.

 

[rabenne]

Well the shitty thing about my datalogger is it can only make 2.5 scans per second... thats per sensor I might add.. Its difficult to get much information, but this is it:


sorry I cant post logs for shit

RPM Timing Adv Air Flow TPS O2 1
(g/s)
1/20/2000 3:03:37 PM 904 7 2 0 540
1/20/2000 3:03:39 PM 824 7 2 8 240
1/20/2000 3:03:41 PM 1556 24 23 37 760
1/20/2000 3:03:43 PM 2824 27 43 47 940
1/20/2000 3:03:44 PM 4048 23 52 58 940
1/20/2000 3:03:46 PM 3832 18 91 49 940
1/20/2000 3:03:48 PM 5316 17 52 84 940
1/20/2000 3:03:50 PM 3664 14 93 71 940
1/20/2000 3:03:52 PM 4324 32 13 0 940
1/20/2000 3:03:54 PM 2928 33 4 0 940
1/20/2000 3:03:56 PM 2664 33 2 0 120
1/20/2000 3:03:58 PM 2292 30 2 0 120
1/20/2000 3:04:00 PM 652 5 2 0 120
1/20/2000 3:04:02 PM 724 5 2 0 120
1/20/2000 3:04:04 PM 756 5 2 0 120
1/20/2000 3:04:06 PM 760 5 3 6 120
1/20/2000 3:04:08 PM 1988 28 14 14 480
1/20/2000 3:04:10 PM 2324 30 18 17 940
1/20/2000 3:04:12 PM 2596 33 3 0 940
1/20/2000 3:04:14 PM 2276 30 3 5 120
1/20/2000 3:04:16 PM 1956 28 4 0 120
1/20/2000 3:04:17 PM 1680 23 2 0 120
1/20/2000 3:04:19 PM 1312 16 2 5 120
1/20/2000 3:04:21 PM 1304 18 17 39 940
1/20/2000 3:04:23 PM 2068 22 32 10 940
1/20/2000 3:04:25 PM 2560 33 7 5 100
1/20/2000 3:04:27 PM 2368 31 2 0 100
1/20/2000 3:04:29 PM 2104 28 2 0 100
1/20/2000 3:04:31 PM 1532 18 1 0 100
1/20/2000 3:04:33 PM 728 5 2 0 100
1/20/2000 3:04:35 PM 736 5 2 9 940
1/20/2000 3:04:37 PM 1560 21 15 28 780
1/20/2000 3:04:39 PM 2456 27 46 35 940
1/20/2000 3:04:41 PM 3552 21 44 65 920
1/20/2000 3:04:43 PM 3484 17 87 61 860
1/20/2000 3:04:45 PM 5096 33 13 2 940
1/20/2000 3:04:47 PM 2804 33 4 0 940
1/20/2000 3:04:49 PM 2596 33 6 9 940


whats going on?





1/20/2000 11:41:20 PM 1048 10 2 0 940
1/20/2000 11:41:22 PM 1036 11 2 0 520
1/20/2000 11:41:24 PM 1028 11 2 0 340
1/20/2000 11:41:26 PM 1036 11 2 0 940
1/20/2000 11:41:28 PM 1048 10 2 0 520
1/20/2000 11:41:30 PM 1036 10 2 0 940
1/20/2000 11:41:32 PM 1064 10 2 0 940
1/20/2000 11:41:33 PM 1040 10 2 0 660
1/20/2000 11:41:35 PM 1080 12 6 3 940
1/20/2000 11:41:37 PM 1392 18 5 7 940
1/20/2000 11:41:39 PM 1300 15 2 1 460
1/20/2000 11:41:41 PM 1988 23 23 30 120
1/20/2000 11:41:43 PM 2104 25 38 30 940
1/20/2000 11:41:45 PM 3728 33 11 30 100
1/20/2000 11:41:47 PM 2608 23 44 34 940
1/20/2000 11:41:49 PM 3384 33 13 25 100
1/20/2000 11:41:51 PM 2424 16 44 100 940
1/20/2000 11:41:53 PM 2860 14 61 100 940
1/20/2000 11:41:55 PM 3416 11 90 100 920
1/20/2000 11:41:57 PM 3932 16 106 100 100
1/20/2000 11:41:59 PM 4388 8 23 0 940
1/20/2000 11:42:01 PM 4216 33 6 0 940
1/20/2000 11:42:03 PM 3952 33 3 0 940


not much of a tuner...feel like an asshole for not being able to recognize my own problems

 

[Kash]

you know what funny i have the same symptoms and ive got a 6bolt swap as well. Other then that the car is pretty much stock besides a bov. Any help would be greatly appreciated.

 

[rabenne]

I have been thinking that a bad CAS could be it... since in the 6 bolt 2gs we use the cam sensor to simulat the crank sensor, the simulation may not be accurate enough as the 90 CAS I have is beginning to wear out.

PLEASE LET ME KNOW OF ANY WAY TO TEST THE CAS!!

 

[redeclipse7782]

Buy a new CAS and put it in if it fixes the problem it was the CAS. Also you re-wired your CAS when you installed the engine into your 2g correct? If you didnt thats your problem, if you did, did you wire it correctly? I believe the dsmlink has an option to invert the CAS as well. If nothing else the dsmlink should help out in more ways then one. Also did you replace your fuel filter? Maybe you could have something restricting fuel flow?

 

[rabenne]

First, about the fuel filter. This seems like a reasonable idea, and at the price of a brand new oem one, I should buy two and keep one on hand. I dont have an electric fuel pressure gauge yet, but plan to get one in a few weeks. Since I dont however, I have no real way to check it.

Next, as for the CAS wiring. The swap was done by the person I bought the car from. It is a 90 CAS. I am almost positive that it is wired correctly because it ran perfectly for months and after sitting for a month it started happening. Hopefully the new ecu and dsmlink will help. The logger ALONE will for sure blow mine out of the water, and I may be able to get a handle on it from there...

I also negotiated to buy the used Denso 660cc's that the dsmlink chip was set up for, for $175 shipped. Lets review how crazy this guy is. He sold me a 2g 95 eprom ecu, already socketed with 660 chip, Denso 660cc injectors, and the dsmlink cable and software for $800 even.


I am going to look around at the hall effect type CAS and maybe buy the RRE plug and play wiring kit. It would be expensive, but as these cars get old you must start replacing everything if you want to keep it for any length of time. It would be well worth the money to know that my cas is new, with a plug and play harness made by dsmgods.

 

[rabenne]

I got the 660's on with DSMLINK and the new ecu. I dont know what fixed it, but the car is running excellent. I am guessing it was the ecu, but I am sending it off to find out. DSMLINK is this best thing ever... everybody should get it. My car is pulling twice as hard as ever, and its still baselined! I cant believe how well its running, I SPANKED A 6.0L GTO!