# LT1 running rich w/ slight miss **URL:** \ **Category:** PittSpeed Automotive\ **Created:** [October 28, 2008, 6:40pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391 "2008-10-28T18:40:05Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![86IROC](https://avatars.discourse-cdn.com/v4/letter/8/c4cdca/32.png) [@86IROC](https://forums.speedlife.net/u/86IROC)\ **Post date:** [October 28, 2008, 6:40pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/1 "2008-10-28T18:40:05Z")
Would anyone have an idea of why my freshly built LT1 would be running rich and how I could fix it? Everything on the motor is brand new, sensors etc. The PCM was tuned for everything I had done to the motor, it has SVO 30# injectors but I just can’t get it to run right… Its just loading up, and it has a slight miss to it while idleing, (it idles around 6-700RPMs) but when I have it reved up in higher RPM ranges you can tell by the MSD DIS-4 that the miss is gone(at least according to the light on the dis4) Any help in diagnosing my problem, or even how to fix it would be great because right now I’m just at a lose. And I can’t even hook up a diagnotic reader because the harness is a 97 OBDII harness, and the computer is a 95, and they just wont comunicate… does anyone know how to connect to the pin outs instead of going through the connector peice? Well thanks for taking a look and hopefully someone will be able to give me some advice. If you need anymore info about my engine or what psi the fuel is running at let me know and I will give you as much info as i can. ---
**Author:** ![69camaro](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/69camaro/32/6046_2.png) [@69camaro](https://forums.speedlife.net/u/69camaro)\ **Post date:** [October 28, 2008, 6:53pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/2 "2008-10-28T18:53:29Z")
who tuned it? sounds like too much fuel at idle to cause a miss. ---
**Author:** ![Orr89rocz](https://avatars.discourse-cdn.com/v4/letter/o/ac91a4/32.png) [@Orr89rocz](https://forums.speedlife.net/u/Orr89rocz)\ **Post date:** [October 28, 2008, 7:44pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/3 "2008-10-28T19:44:05Z")
i’d start with the tune but if i remember right, you have a hotcam’d car? those are very common builds and most of the mail order guys can nail down those combos very well on the first try sure your getting good spark/ignition at idle? possible air leaks in the intake that could cause it to run richer than it should? ---
**Author:** ![SPC\_Wright](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@SPC\_Wright](https://forums.speedlife.net/u/SPC_Wright)\ **Post date:** [October 29, 2008, 5:25am UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/4 "2008-10-29T05:25:42Z")
i had an intake leak that caused it to be rough like that. Was the it checked for intake leaks? ---
**Author:** ![86IROC](https://avatars.discourse-cdn.com/v4/letter/8/c4cdca/32.png) [@86IROC](https://forums.speedlife.net/u/86IROC)\ **Post date:** [October 30, 2008, 7:24pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/5 "2008-10-30T19:24:00Z")
I know I had bolted everything down to proper torque specs on everything… otherwise just from my own confidence how could i check for an intake air leak? just re-tighten everything? And I got my PCM tuned from [350LT1.com](http://350LT1.com), i forget the guys name but I had it tuned for everything I had done to my engine… I gave him all the specs from engine bore to rear end gears. But i forgot to mention I have to have the throttle cracked a little while im cracking over the engine for it to start up right away? I mean it will start up without pushing down the pedle a little but it takes a lot longer? and something else i dont really understand is when I put a fuel pressure gauge to the shratter valve on the rails and its only showing 45psi? i thought these cars ran at like 60? and when I rev the car up it goes to about 50-55psi but not above. But that doesnt make sense that there is not a lot of fuel pressure and the car is running rich. I just wish there was someone in the pittsburgh area that had a lot of experience with tuning LT1 cars, but unfortunetly it looks like everyone has moved on to the LS engines :-/. ---
**Author:** ![danhr](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@danhr](https://forums.speedlife.net/u/danhr)\ **Post date:** [October 30, 2008, 7:34pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/6 "2008-10-30T19:34:14Z")
fuel pressure is fine… ls1’s run that high… lt1’s dont checking for an intake leak is easy… spray in various obvious spots (where the intake meets the heads, throttle body, elbow, etc) with a can of brake cleaner and listen for the idle to raise. you may want to figure out the communication issue. you should be able to communicate with the pcm, 95 f-buckets came with obd-i computers but obd-II style connectors, which should be your best bet. ---
**Author:** ![Jeff95TA](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jeff95ta/32/5935_2.png) [@Jeff95TA](https://forums.speedlife.net/u/Jeff95TA)\ **Post date:** [October 31, 2008, 3:05am UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/7 "2008-10-31T03:05:42Z")
Do you have a cable for hooking to the port? Am I understanding that you already tried this and it didn’t work? If not, I have one you can use with something like Datamaster (it’s free for the first xxx number of scans). ---
**Author:** ![Orr89rocz](https://avatars.discourse-cdn.com/v4/letter/o/ac91a4/32.png) [@Orr89rocz](https://forums.speedlife.net/u/Orr89rocz)\ **Post date:** [October 31, 2008, 4:43am UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/8 "2008-10-31T04:43:15Z")
> But i forgot to mention I have to have the throttle cracked a little while im cracking over the engine for it to start up right away? It has too much fuel at startup if you have to do that. Just gotta take some out during cranking, or it could be too rich at idle to begin with ---
**Author:** ![oneslowbowtie](https://avatars.discourse-cdn.com/v4/letter/o/d78d45/32.png) [@oneslowbowtie](https://forums.speedlife.net/u/oneslowbowtie)\ **Post date:** [October 31, 2008, 9:57am UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/9 "2008-10-31T09:57:51Z")
> [@86IROC"](#): > > I just wish there was someone in the pittsburgh area that had a lot of experience with tuning LT1 cars, but unfortunetly it looks like everyone has moved on to the LS engines :-/. Bryan Herter [www.pcm4less.com](http://www.pcm4less.com) 724-349-3341 9am-7pm He is located in Indiana PA-an hours drive and you can have your car tuned correctly ---
**Author:** ![Laura00WS6](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/laura00ws6/32/6017_2.png) [@Laura00WS6](https://forums.speedlife.net/u/Laura00WS6)\ **Post date:** [October 31, 2008, 12:40pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/10 "2008-10-31T12:40:58Z")
guess none of the stuff adam told pat worked? ---
**Author:** ![BooSSted\_SS](https://avatars.discourse-cdn.com/v4/letter/b/5f9b8f/32.png) [@BooSSted\_SS](https://forums.speedlife.net/u/BooSSted_SS)\ **Post date:** [October 31, 2008, 9:11pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/11 "2008-10-31T21:11:38Z")
well it sounds to me like it idling a bit low. I normally set my Camaro to idle at 800-850 RPM’s at idle. Also the fact that it’s dumping gas into the cylinders would be my best guess on why it’s missing… ---
**Author:** ![86IROC](https://avatars.discourse-cdn.com/v4/letter/8/c4cdca/32.png) [@86IROC](https://forums.speedlife.net/u/86IROC)\ **Post date:** [November 1, 2008, 4:24pm UTC](https://forums.speedlife.net/t/lt1-running-rich-w-slight-miss/200391/12 "2008-11-01T16:24:48Z")
yea, im gonna give bryan from pcmforless a call if we cannot correct the problem this week, but no, none of the things adam told pat worked out. But thanks for the info on the pcm guy, i didnt know he was indiana.