car jerks after afpr

[99 gst spyder]

after afpr install, car jerks at 3k rpm once only on first gear, and then drives normal. afpr is set to 36 psi with vaccum off and drops to 26ish when vacumm is plug and at idle. 255pump not rewire yet, this could be the case i'm not sure. other than that it drives great.

did a compression test with cold motor. 150-148-147-120. will retest with hot motor.

plan to get it tuned/dyno soon. is this too much of a low compression test or will i be ok for a dyno/tune?

mod in profile. the difference before dyno is i'm going replacing it with
fp green/ported 2g manifold/ 38mm external gate/1000cc.

thanks

 

[9!'clipseDOHC]

Why is it set at 36 psi? Factory base is 43.5 and that's a pretty standard number. Did you input the 36 psi in v3 so its calculated in the globals?

*EDIT

Actually I'm a little confused because you have a picture of a 2g but it says you have a 1g in your profile.

Also in regards to you compression test, here are the factory specs (for ALL DSMs since I don't know what you have):

1G (90-94) T/E/L 1.8L NT engine
Compression ratio 9.0:1
Standard compression 185 psi
Service limit 131 psi

1G (90-94) T/E/L 2.0L NT engine
Compression ratio 9.0:1
Standard compression 192 psi
Service limit 145 psi

1G (90-94) T/E/L 2.0L Turbo engine
Compression ratio 7.8:1
Standard compression 164 psi
Service limit 121 psi

2G (95-99) T/E 2.0L NT 420A engine
Compression ratio 9.8:1
Standard compression 170-225 psi
Service limit 100 psi

2G (95-99) T/E 2.0L 4G63 Turbo engine
Compression ratio 8.5:1
Standard compression 178 psi
Service limit 133 psi

2G (95-99) T/E 2.4L NT Spyder engine
Compression ratio 9.5:1
Standard compression 192 psi
Service limit 146 psi

There is also a service limit for maximum allowable pressure difference (MAPD) between any two cylinders. For all engines except the 420A, the MAPD between any two cylinders is 14 psi. The 420A is allowed a 25% difference between cylinders.

So either way that 120 cylinder is a problem.

 

[99 gst spyder]

the 2g spyder is my previouse ride, now i have a 1g talon just haven't upload the picture's.

so i set the afpr psi at 36ish and drop to 27 pluged at idle. still jerks.

what can be the cause a the low compression, i've heard that it could be rings, seals or other things.

 

[antilag]

A 20% diffierence in one cylinder is not a good thing. I would guess a cracked ring land. I would not try to push it on a dyno until you are sure what the problem is and fix it.

Redo the compression test and if you get the same numbers, run a leak down test in the bad cylinder to find where the loss of compression is stemming.

 

[DSMTyson]

Set the base fuel pressure at 43.5 PSI.