951 Running lean at idle and part throttle but ok at WOT
12-31-2018, 12:58 AM
#1
Intermediate
Thread Starter
Join Date: Mar 2015
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
951 Running lean at idle and part throttle but ok at WOT
Trying to figure out why my 86 951 is running lean at idle and cruising speeds. WOT I'm at 10.9-11.2 on my Wideband but at idle I'm at 15.9-16.9 and at cruising speeds around 15.2. Cold start it'll be at 10.2 for about 30 seconds and then creeps up to 15-16 as it warms up. Idles a tiny bit jumpy maybe +/_20 rpm
1.Entire motor rebuilt 3 years ago.
2.New injectors flow matched/silicon vac lines/sensors/everything pretty much besides the wiring harness was replaced back in 2015.
3."S" turbo Rebuilt by GpopShop
4.951 MAXHP chips
5. 3 Bar FRP
6. Rebuilt stock AFM back in 2013
Any info would be greatly appreciated! Thanks guys!
1.Entire motor rebuilt 3 years ago.
2.New injectors flow matched/silicon vac lines/sensors/everything pretty much besides the wiring harness was replaced back in 2015.
3."S" turbo Rebuilt by GpopShop
4.951 MAXHP chips
5. 3 Bar FRP
6. Rebuilt stock AFM back in 2013
Any info would be greatly appreciated! Thanks guys!
01-01-2019, 12:25 PM
#4
Intermediate
Thread Starter
Join Date: Mar 2015
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
I have used a smoke tester and triple checked all vac lines and I'm not finding a leak, Im not sure what you're asking on the O2 sensor? I have a bosh unit in place thats hooked into the ECU like normal.
What should be normal AFR at idle and cruising? Maybe its my chip? I drove my buddy 951 in the past and his was much more on the rich side. 13-13.4 at idle and cruising at 12.1-12.9
What should be normal AFR at idle and cruising? Maybe its my chip? I drove my buddy 951 in the past and his was much more on the rich side. 13-13.4 at idle and cruising at 12.1-12.9
01-01-2019, 01:03 PM
#5
Addict
Rennlist Member
Rennlist Member
So you have a 2nd O2 bung for the wideband?
If your O2 is working the DME should adjust the AFR other than for WOT. Try disconnecting the O2 sensor and seeing how that affects your AFR, it might get leaner or richer or not change. Any of those outcomes would be interesting.
If your O2 is working the DME should adjust the AFR other than for WOT. Try disconnecting the O2 sensor and seeing how that affects your AFR, it might get leaner or richer or not change. Any of those outcomes would be interesting.
01-01-2019, 10:39 PM
#6
Intermediate
Thread Starter
Join Date: Mar 2015
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
Turns out it was my Chip set. I swapped back the "original" SuperChip and now I'm running much better. 14.2-14.7 at idle now and WOT is 10.9-11.2 and cruising is at 13-14.
Also my turbo spools up sooner and now I've got real boost in 1st gear. Happy camper!
Also my turbo spools up sooner and now I've got real boost in 1st gear. Happy camper!
01-02-2019, 12:29 AM
#7
Drifting
Interesting. My buddy in Ottawa has the 951MAX chip with otherwise stock car and it seems to run great. Perhaps your chip was for the non-S turbo (if that would make a difference)? When ordering, Lindsay does ask you to specify which turbo. When I install a WBO2, I'd be happy to test your MAX chips 
What's a "SuperChip"?
What's a "SuperChip"?
Trending Topics
01-03-2019, 10:50 AM
#8
Intermediate
Thread Starter
Join Date: Mar 2015
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
SuperChips is what i believe IAN installed from 944online, looking at recipets from the past, i could be wrong though maybe it was customer supplied. Looks like they are more European based going off of google, but she runs great now and no more crazy pops and flames shooting out. It was fun at first but it gets old real quick and Police aren't to fond of it either haha
01-03-2019, 12:18 PM
#9
Drifting
I was getting occassional pops but they seem to have disappeared after I cleaned the AFM and adjusted the wiper. Were you getting pops at part-throttle shifts or full throttle? I am curious if you were getting pops while running lean
01-04-2019, 01:11 PM
#11
Drifting
I can see the pops immediately after taking foot off the gas (ie. shifting), but since the DME shuts the fuel when decelerating (turning it back on aprox. 1200rpm), I bet the 951MAX chips eliminate this operation. Interesting
01-04-2019, 02:52 PM
#12
Intermediate
Thread Starter
Join Date: Mar 2015
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
Yea I'm guessing, I loved the power the 951max chip gave the car, but its not worth the lean issue. Ill probably go VEMS when i have a little more pocket money since my has a decent amount of mods done.