Car pulls harder at part throttle than at WOT

[Torvus]

Thanks for the TTT Kwik . Ok, here's the latest, it appears that on the Tlink, it stops reading input from the ECM when it enters PE mode. Started looking through my stats and noticed that I only show one TPS reading over 4.0 TPS, and it even shows a 1.9 voltage (instead of 13). Reading through a run from last night and will post results momentarily. Any thoughts please post of what would cause no readings from the ECM at WOT?

 

[Torvus]

Ok, here's the last line read before WOT on the T-link of a 25 mph roll WOT run to about 70 mph.

MPH - 28
RPM - 2575
TPS - 3.12
MAF - 117
02 - 16
XCNTS - 250
LV8 - 200
INT 150
BLM - 114
KR - 0
MAT 42.4 (read 106 previous line)
IAC 101
Volts - 6.5 (read 13.1 previously)
EGR - 2
Learn- Enabled

Here's the next line read (apparently after release throttle) :

MPH - 62
RPM - 2575
TPS .59
02 - 207
XCNTS 9
LV8 - 90
INT 117
BLM 117
KR - 0
MAT 110
CTS 178
IAC 89
VOlts 13.1
EGR 0



Strange that it didn't read anything from the quick run. Any thoughts?

 

[Torvus]

calpack maybe?

 

[mgmshar]

...something you said that scares me. You said you are running a stock fuel pump. My understanding is that the stock fuel pump is marginal for our cars, even in stock form. With higher boost (above 15psi), it's inadequate.

When you get your fuel gauge, tape it to the windshield. Watch it very closely when you get on the throttle. The fuel pressure should go up one-for-one with boost. If your base pressure (setting with vacuum hose removed) is 45psig, then it should be 60psi at 15psi boost. And, it should stay rock steady with rpm.

I'm going to guess that your fuel pump is giving up at higher boost. When it does that, car leans out, lots of knock retard, lower performance. In any case, I would DEFINITELY check it.

Good Luck,

 

[Torvus]

It has been hot wired, but when I run boost above 15# I run alky. Otherwise the car has been running fine with only 14# of boost with no KR with the current setup. This problem has just recently reared it's head. I plan on checking FP as soon as possible, but I'm more concerned with not getting any readings back from the T-link at WOT than I am about the fuel pump.

 

[BlownZ]

Have you emailed Ken Mosher for advice? He wrote the T-Link software from my understanding and could likely offer some input.

 

[Torvus]

Good point, I've been so busy with trying to locate a spare ECM for Wed. that I haven't had time ( plus I work weekends)

 

[Torvus]

UPDATE...

I replaced the springs (which didn't seem much better than the old ones). The car ran fine at 10#, shifting perfect and all. Turned it up to 15# and still the same affect. Car still runs better at 3/4, you can lift and feel the car accelerate. I've recently added a new Walbro FP, checked all lines, fuel filter, T-link is still not reading at WOT (which may not be related). I also installed a scanmaster, high reading was ~840 and 2.4 kr. FP is set at 42 with stock injectors. I've tried ECM's, grounds, Coil packs, and calpacks. I haven't tried a different chip but that's next. I doubt it would be a cam sensor, or crank sensor, after a search I'm not finding signs of any problems with them. Also thought about a MAF dropout, but it's not a miss which is the usual symptom for the dropout. Any more thoughts?

 

[Pronto]

What's your TPS at WOT?

 

[BJM]

When I first started on this board the instant someone said they had more power at part throttle everyone would say your cam sensor was 180 degrees out. I didn't notice if you have tried changing it.

 

[Torvus]

TPS is around 4.3..cam sensor is in right. If it were 180 out I would def. know, but I appreciate the info.

 

[bishir]

TPS should be at least 4.5 at WOT I noticed in your earlier WOT pass your TPS was in the 3s.... Either you need to set it correctly, or buy a new TPS.

James

 

[Torvus]

I checked it again and it's at 4.68. I worked again on it for a little while getting my IAC down from 100 to 10-20 range. I just put in the 009's, but haven't been able to make a full pass yet due to some unforseen problems (injector fuse left me stranded last night due to a frayed wire grounding out). I'm going to drive it around a bit with the 009's and see how it reacts.