Converted to e85 car backfires under WOT

[DMAC]

I converted my hot air 84 GN to the following

87 intake
IC
87 TB with power plate
t -49 turbo
80 lb injectors
140 amp alt
elec fan
Hot wire kit
DW E 85 comaptible fuel pump
boot controller
boost gauge
knock guage
EGT gauge
TT E 85 chip


The care seems to pull hard at lower boost levels but when it gets to 17 or above it seems to stumble and will shutter and back fire all other driving and acceleration at lower boost levels seems to be fine. Anyone have any ideas?

 

[jasjamz]

Scantool? Wideband?

 

[DMAC]

I have a POS turbo link that has an error pop up ... about to trash it and order a scan master

 

[jasjamz]

Does it give you any info that you can trust/use?

 

[DMAC]

Not as of yet I am trouble shooting the turbolink that I purchased some time ago before I put down the 250 for the scan master . But If I dont figure out the issue I am going to go ahead and order the scan master.

Car seems to do fine essing into the throttle but if you floor it at WOT it backfires at high boost and stumbles

 

[TurboBuRick]

1st thing that comes to mind is a loose intercooler coupling.

 

[Hot Air]

Need to know the air/fuel ratio @ wideband. Do you have a fuel pressure gauge? Are you running out of pump or injectors? Any knock?
Conrad

 

[TurboBob]

I have had a bad plug wire act that way and a bad spark plug.

(there are LOTs of things that can cause it)

Has it ever run right after the conversion?

Bob

 

[DMAC]

It hasnt r.un right at WOT since converting. it was running around 14.3 but it goes down to 10 -11 when I accelertae and then goes past the 17 at wot on the air/fuel gauge. I dont have a fuel presure gauge but I set the fuel preasure at 43 psi and it holds there under idle



I did notice the fuel preasure bled down quickly when I shut the car off . but they are brand new injectors so I didnt think much about that aspect and brand new plugs and wires but I will certainly check those as well.

 

[jasjamz]

Leaning out could be from lack of fuel. Say out of WOT and high boost intil you get the right stuff to work with your combo.

 

[its2qik]

It hasnt r.un right at WOT since converting. it was running around 14.3 but it goes down to 10 -11 when I accelertae and then goes past the 17 at wot on the air/fuel gauge. I dont have a fuel presure gauge but I set the fuel preasure at 43 psi and it holds there under idle



I did notice the fuel preasure bled down quickly when I shut the car off . but they are brand new injectors so I didnt think much about that aspect and brand new plugs and wires but I will certainly check those as well.

Brother, if that gauge is accurate, your car is going dead lean at WOT, which is gonna break stuff if you keep it up.

 

[DMAC]

Ok am not doing the WOT .. was concerned if the boost was not set at 21 lbs it would run lean since the chip was burned for that. Not sure what could be causing it to go lean and trying to do process of elimation I guess

 

[TurboBuRick]

Fuel pump and fuel pressure regulator would be a spot to start diagnosing.

 

[jasjamz]

Mass air flow meter pegging at 255? If not, that's a problem too.

 

[87GN_70GS]

A single DW pump will not supply 80 lb injectors above 90% dc or that go static. Check your fuel pressure with something you can monitor at WOT and check for fuel pressure tracking with boost.

 

[DMAC]

I got the scan master here is some of my readings Any comments?

Engine Off Cold Idle Warm Idle 15 Min Drive
Af 0.4 14 09 06
L8 00 61 59 38
baE 11.7 14.2 13.9 14.0
Ine 128 128 112 112
BL 128 121 118 118
MPH 00 00 00 00
CLE 60 101 171 167
AES 71 71 71 71
r 000 975 850 875
Eps .40 .42 .42 .42
IAC 140 29 02 01
CC 28,146,80.224 28,146,80.225 28,146,80.226 28,146,80.227 This jumps around constant
NAL 00 00 00 00
605 0 585 527


Ordered a voltage booster and hope to have it installed by weekend....

As a precautionary I have also ordered -10 feed and -8 return lines as next steps

 

[Daniel Jost]

17AFR does not always mean that you are lean, it can also indicate a misfire as there is a ton more un-burnt oxygen in the exhaust. I have had this happen before, actually on E85 before I went to LSx coils.

,Dan