Tech / General EngineWhy is my car making that sound? My car won't start! Combination questions? Don't see a board for your problem or have other technical or engine specific questions? Post them here!
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I just got the car back from the shop and wanted to share my numbers with you guys. So far the Motor is putting down 306.5 rwhp horsepower at 4800 rpm. And 419.3 ftlbs of rwt at 3200 rpm. IM pretty happy with the numbers so far. The throttle responce is awesome. There is alot left in it I think. I have a set of Edelbrock headers on the car. The pipe size and welds in the ports are hurting it all around. If theres one thing ive learned over the past few weeks about a 400. You need a good exhaust system!
I Also have what Steve and I beleive to be an ignition problem. Ive replaced everything but the pickup coil and module. Its doing something really weird between 2900-3500rpm. You can see the power and torque fall off to nothing. Then at 3500 its over 400ftlbs...Anyone have any ideas what the problem is? I have an MSD ignition, It seemed to start after I opened the gap up to.050 not sure though. IM thinking about replacing the plugs and gapping them at .040. You cant really feel it that much driving it but on the dyno sheet its there.
Just a little FYI if you are in the Tampa bay area TuneTechauto.com is a great place to take your car. Steve is a great guy and went out of his way to get my car where it is now.
Thanks to RB83L69,Glenn91L98GTA,Madmax,and others who have helped in one way or another over the course of this buildup.
I have had the same problem with my ignition before. Change the coil and module. Don't buy generic aftermarket parts though. I mean, the store brand. I used the Accel ( I know it's border line generic), super HEI coil along with their module. Problem solved.
The motor should start and run much smoother and more fluid.
Hey gruveb..The pickup coil and module are the original pieces. The coil is an MSD that I bought from someone on this board. He said it was not that old.
The car does have a small miss at idle, it starts fine. But it seems to Take more turns of the motor to start then it did before.
I just installed a Walbro 255lph fuel pump so I dont think its fuel related. Steve said the fuel curve was right on.
IM going to try the pickup coil and the module and see if that helps. They are old anyways. I checked all the grounds at the back of the heads and they look good.
Hey congratulations Mike! Glad to hear everything went well! I think you have alot more in that motor though, and I'm sure alot of it is attributed to the ignition. Whatever you do don't get an MSD cap or rotor. I had them on my car and they carbon tracked so bad. I put borg-warner on it and its like 20x better. As far as ignition, I'd look into the Accel 300+, or if that tick tick tick sound bothers you, look into Jacobs. I'm sure theres nothing wrong with MSD, but I wasn't impressed at all.
I'd bet that by the time you're done, you're cranking out 350 RWHP. Congrats again bro!
Thanks Jason ...I am really sold on chassis dynos and a good tuner. After I get the ignition sorted out,I plan to upgrade my exhaust. There is at least 15rwhp in a larger set of headers. The peak power numbers our decent. But.. its how strong the car is from there to idle that makes the car so fun to drive..even at part throttle. I think the displacement of the motor is the main reason for that.
Just an observation, I think at about 3000 rpm MSD systems stop being "MSD" systems. In other words you can't charge up fast enough at 3000 rpm to get multiple sparks. I don't see that causing a drop in power though, but maybe something internal to the MSD box is having a problem?
Good luck
Corry
Well..I tried disconnecting the MSD box. It Didnt help The car runs better with it. I rebuilt a second distributor last night with a new pickup coil and module. IM going to install it tonight along with the new plugs gapped at.040 and see if that helps.
<font face="Verdana, Arial" size="2">Originally posted by MikeH: Well..I tried disconnecting the MSD box. It Didnt help The car runs better with it. I rebuilt a second distributor last night with a new pickup coil and module. IM going to install it tonight along with the new plugs gapped at.040 and see if that helps.
Thanks Matt...IM still trying to find out whats up with my ignition. I put the new pickup coil and module in last night. I go to set the base timing so i disconnect the Brown bypass wire. Start the car up and it dies runs for a second and dies. I did notice that it starts much faster but only with the MSD connected and the bypass wire disconnected. So I disconnect the Msd box and hook up my stock ignition it runs fine with the wire disconnected. I can set the intial timing but with the Msd box pluged in it dies out. Why wont it run with MSD pluged in with the bypass wire disconnected? Is this the way its designed? If I connect the bypass wire it will run eitherway with the Msd Box or the stock ignition.
Hey Drive it....The cam is an LPE/Accel cam part number 213 its for a 383/406 using the SuperRam intake. The specs on the cam are 224/234* 465/488 lift with 112Ls.
I sure hope its those crappy TES headers choking it off, because you're making the same power I am with 56 more cubes! Are you the guy who thru the 400 block in his daily driver just because he had one?
<font face="Verdana, Arial" size="2">Originally posted by MikeH: Thanks Matt...IM still trying to find out whats up with my ignition. I put the new pickup coil and module in last night. I go to set the base timing so i disconnect the Brown bypass wire. Start the car up and it dies runs for a second and dies. I did notice that it starts much faster but only with the MSD connected and the bypass wire disconnected. So I disconnect the Msd box and hook up my stock ignition it runs fine with the wire disconnected. I can set the intial timing but with the Msd box pluged in it dies out. Why wont it run with MSD pluged in with the bypass wire disconnected? Is this the way its designed? If I connect the bypass wire it will run eitherway with the Msd Box or the stock ignition.</font>
I'm not sure why it is doing that, but if you can get it to idle with the bypass disconnected (with or without the MSD box), and set the base timing where you need it to be, just let her buck and get it done. It could be worse.... ... Get the base timing set with the bypass off and put it all back together. Maybe give everything a once over and make sure that it is all connected correctly.
So how does it run now with all of the ignition parts replaced? Did you go back to the dyno yet?
Good Luck
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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam My GTA
Hey Guys..IM not sure what the exact Problem was I changed so many things. It pulls much harder on the topend. Its smoother all around too Before it would die out around 5000 i could spin it to 5500. Now it pulls to 6000 really strong. Not bad for a TPI motor. Its no MiniRam...but it has a decent topend to it now. On the first blast I couldnt beleive it was pulling that high. My peak power feels like its around 5300 rpms now. I cait wait to get it back to the shop and see what kinda of numbers it will make with some more tuning.
I Had to set the timing with the MSD bypassed. The MSD tech said its proably running lean thats why it wouldnt run with the MSD hooked up. My pickup coil was full of green crud. The number 4 plug wire had burned thru and was arching on the airtube. Thats the last time I buy those cheap *** Accel superstock wires. No offense to anyone who likes them they just havent worked to well for me. Ive been thru two sets in the past year. I just put this set on a week ago. It wasnt even touching the header. IM going to bite the bullet and get a set of MSD wires.
Kevin those are good power numbers you are making. I bet you have a 12 second car now. IM sure the headers are chocking the motor on the topend. I will probably end up changing them out at some point. It will drive me nuts knowing there is more power there. I did have the 400 in my 91 RS. I only had 10,000 miles on the short block and someone rearend me I managed to salvage alot from it.
I just wanted to post this incase someone else is having the same problem. Philip you are the man I should have listened to you from the begining. After driving my car for a few days I could still feel the car going flat from 2000 to 3500 So I swapped out my MSD coil for the stocker and its a whole new car. The pickup coil and module helped smooth out the car but the coil was the major problem. IM going to get a replacement this week.
I hope to go back to the dyno this Friday for some more tuning.
Congrats again bro!
The car runs better with it. I rebuilt a second distributor last night with a new pickup coil and module. IM going to install it tonight along with the new plugs gapped at.040 and see if that helps.
