fuel pump and injector question with modified engine.
Thread Starter
Racer
Joined: Aug 2012
Posts: 337
Likes: 71
fuel pump and injector question with modified engine.
Back in fall I did a head cam and super ram on my 86. Got the car running. Runs better than I expected with the stock chip. I called a dyno tuner in my area to ask if they did tuning on older obd 1 cars and if they could burn a new chip. The guy said yes said I would be looking at around 550 bucks. I told him what I did to the car 180 afr heads mild flat tappet cam and the intake. He started to tell me that I will probly need to change the fuel pump and the fuel injectors. My guess is with what I did I added 100 to 125 more hp wouldent 24 pound injectors and the stock fuel pump be just fine? If so should I not evin waste my time with this shop and just get a mail order tune? Whad do you guys recomend I do? Thanks
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
Back in fall I did a head cam and super ram on my 86. Got the car running. Runs better than I expected with the stock chip. I called a dyno tuner in my area to ask if they did tuning on older obd 1 cars and if they could burn a new chip. The guy said yes said I would be looking at around 550 bucks. I told him what I did to the car 180 afr heads mild flat tappet cam and the intake. He started to tell me that I will probly need to change the fuel pump and the fuel injectors. My guess is with what I did I added 100 to 125 more hp wouldent 24 pound injectors and the stock fuel pump be just fine? If so should I not evin waste my time with this shop and just get a mail order tune? Whad do you guys recomend I do? Thanks
Melting Slicks
Joined: Mar 2008
Posts: 2,141
Likes: 76
From: Santa Maria, CA
Just heads and Super Ram are not going to get that engine to 300 RWHP. Add headers and it gets closer. We need to know the rest of the build. Even if his mods added 100HP, the 24# injectors with tuning will suffice.
Thread Starter
Racer
Joined: Aug 2012
Posts: 337
Likes: 71
I do also have long tube headers. I guess technically my injectors are not stock. I have 24# injectors I replaced years ago I think the stock ones were 22#. I just never remember hearing on the forum any one saying bigger injectors or a bigger fuel pump are needed for what I have done to the engine. I do think it needs a chip made to help it run better. I no longer have the cold start injector on the car. The car wont idle all that great until it's fully warmed up. Once warmed up it's not too bad. When cold if you stab the throttle it will some times die. I am just wondering every ones thoughts on here.
Melting Slicks
Joined: Mar 2008
Posts: 2,141
Likes: 76
From: Santa Maria, CA
I would contact PCM4Less about a tune. See what they think about the injectors. My guess is they're OK. The headers really do make a difference. I ran my setup with stock manifolds and with headers and there is no comparison. You're probably running lean.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 413
From: WV
I agree , you should get a tune done. When I had my 383 built a few years ago I talked to Jon at FIC about injectors and he said with 370 hp I would need 24 lb injectors, if anyone would know about injectors, it would be Jon Banner at FIC....The guy that did my tuning said with this hp I should step up to a higher output fuel pump, I went with the Walbro 255 fuel pump kit.. If you have the original fuel pump in your car its probably a good idea to change it out anyway..WW
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Your stock pump should be good up to about 400 HP. The injectors should not be a problem either, especially if you went from 22 to 24 lb.
Go for the tune.
Your set up is similar to mine and my tune is great without a problem.
Go for the tune.
Your set up is similar to mine and my tune is great without a problem.
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Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
My 87, stock pump did not keep up with a ZZ4/180 motor. Watching a FP gauge and the wide band while on a dyno showed it.
Thread Starter
Racer
Joined: Aug 2012
Posts: 337
Likes: 71
Thanks for the help guys. The fuel pump in the car is about 3 years old. Due to the old one crapping out on the side of the road. I was able to change it out on the side of the road just had to call a friend to bring me some tools and a trip to the parts store. Anyway I think I will just call pcm for less. I am just not sure if I trust this shop. They are located in a town about 45 min away from ware I live. I grew up in the town they are located and just recently heard about this place. So I know they have not been around too long. I know that doesn't mean they don't know what they are doing either. They do have a nice web site with examples of cars they have done but they are all either newer modern computer controlled cars or cars with carbs. I was just suprised how the guy I talked to almost insisted the fuel pump and injectors needed up grading. He actually asked me to if my car a 86 had the tuned port engine. I said yes a l98. So just that makes me think he has no experience with these older computer controlled cars. My gut feeling is I would be better off calling pcm for less.
Last edited by red86silver78; Jan 15, 2013 at 12:03 AM.
Safety Car
Joined: Nov 2009
Posts: 3,973
Likes: 341
From: Adelaide South Australia
After i did all my mods the engine wouldnt rev past 4500, I could feel the knock sensor activating so i knew it was leaning out,
the last mod i did was a 255 LPH fuel pump, and guess what, 5500 rpm !
this was with the Fastchip already in.
the last mod i did was a 255 LPH fuel pump, and guess what, 5500 rpm !
this was with the Fastchip already in.
Thread Starter
Racer
Joined: Aug 2012
Posts: 337
Likes: 71
Well I talked with a guy from pcmforless today. Told him pretty much everything that has boon done to the engine. He said I should be fine with the stock pump and 24# injectors. Like I said I have driven the car since doing everything. I can't believe how hard the car continues to go above 4500 rpm. I have taken it up to just under 6000 rpm and it pully hard the whole way. I am just thinking I will data log it and have pcmfor less burn a new chip.