Another modded 951 not starting

Flitzr951 · 10:37 AM

I just finished my 951 after 2 years of work and it cranks but won't fire up.

- Darton MID sleeved 2.7L block
- LR Garrett Super 75
- LR Cam
- LR MAF/MAFterburner
- LR 951 MAX chips
- LR Stage 1 head w/high velocity exhaust
- Cometic head gasket
- LR Stage 3 intercooler
- LR Boost pipes
- LR dual port WG
- Adjustable FPR
- 55lbs siemens injectors
- 3" race exhaust
- Innovate WB O2
- Raceware head studs/rod bolts
- MSD Blaster coil w/magnacore wires

The engine was completely disassembled and rebuilt with all new gaskets, bearing, rollers, belts etc. Everything seems to be in sync but it won't start. It fires on occasion but nothing consistant. The MAF/O2 stuff checked out properly. I reinstalled my factory injectors last night and it felt like it was about to start but then it would die. I found out my number 2 injector was leaking really bad and I could only hold about 20lbs of fuel pressure. I believe the lack of fuel pressure was to blame for it not starting, but does that mean my 55lb injectors are not working properly? Of course there could be more to it than meets the eye which is why i wanted to get some other minds on this and hopefully figure it out. Thanks

legion · 08-07-2007, 11:28 AM

Are you getting spark?
Are the injectors firing?

You are running a "chipped" DME/KLR? Were the chips burned for your setup?

blown 944 · 08-07-2007, 12:20 PM

If it is only holding 20 psi You may have flooded that cylinder,,,I can't stress this enough ....BE CAREFULL.....you can hydrolock a cylinder with fuel if your injector is leaking. his can result in a bent rod or broken piston

To be safe I would unhook the coil and remove the plugs and turn it over to releive the cylinder of excess fuel.

With the info you have provided I would look closely at the fuel system mostly the injectors. Make sure all is good with them before going any further or you could have some serious problems.

Once the fuel system is sorted then I would check the spark by removing a plug wire and inserting a new plug to see if your ignition is fireing.

Try to narrow it down a bit starting with fuel,then ignition

Flitzr951 · 08-07-2007, 01:03 PM

As far as I know, the plugs are firing...they are brand new and there is spark between the cap and each individual ignition wire. The #2 injector was leaking out of the head, not into the cylinder (probably just not seated correctly) so I'm not too concerned with flooding the cylinder. Would the lack of resistors for the 55lb injectors stop it from starting? I was told they were bolt on, but I've learned not to believe everything when it comes to that sort of thing. It was my understnading that the injectors would still work without the resistors, but it would work the computer more. The chips I have were burned for my car.

nynor · 08-07-2007, 01:34 PM

there is an earlier post where someone used 55lb injectors on their car and now it won't start.

Flitzr951 · 08-07-2007, 01:54 PM

There's another thread but his engine is starting, it was having problems revving up. It looks like the MAFterburner was the answer for him, I already have it wired in and ready to tune as soon as it starts.

blown 944 · 08-08-2007, 06:38 AM

So what is the fuel setup like now.

Is it holding psi?

Does it start and die or no start?

It should be able to fire up and idle on the dme idle map if the TPS is adjusted properly, check to make sure the TPS is functioning. This would eliminate the MAF setup altogether.

What is the resistance on the injector? 2.4 2.6 16.0 5. ?

Test across pins.

myskyon · 08-08-2007, 07:21 AM

ok to be diffrent for everyone else right now. did you load a tune into your Mafterburrner? if not it may not start. I would download one of the ones on the LR site and load it. if you havent allready. and go through and set it all up right. that can cause a headache. also another thing to check is your dme relay, fuel filter, GAS, and maybe some other stuff i cant think of now.

myskyon · 08-08-2007, 07:23 AM

Quote:

Originally Posted by blown 944

So what is the fuel setup like now.

Is it holding psi?

Does it start and die or no start?

It should be able to fire up and idle on the dme idle map if the TPS is adjusted properly, check to make sure the TPS is functioning. This would eliminate the MAF setup altogether.

What is the resistance on the injector? 2.4 2.6 16.0 5. ?

Test across pins.

it will not start if the wireing for the maf is not right or the maf is not hooked up. and if i remember mine wouldnt hold an idle with out a tune. i just downloaded the one from LR.

Flitzr951 · 08-08-2007, 07:30 AM

Well i talked to the guys at Lindsey and they said it should start fine as long as I have thier chips in. I wasn't able to work on it last night so I'm still suspect of the fuel injectors (which I also need to check the resistance on) so I'll be starting there and work my way to the tune if that seems to be the issue.

blown 944 · 08-08-2007, 07:46 AM

Hmm, I have always been able to start and idle with the AFM unplugged, does the MAF setup override the idle map?

After thinking...... the new chipset should have the idle map built in for the bigger injectors..correct

Flitzr951 · 08-08-2007, 07:56 AM

yes, the chips are set up for my injectors and cam etc

Flitzr951 · 08-09-2007, 06:22 PM

Okay, so I reseated the leaking injector and it started right up. There is a fairly steady idle (not sure what's it's supposed to be like with the new cam) but lots of noise. There is too much to describe, sounds like detonation not much like mechanical banging.

blown 944 · 08-09-2007, 08:57 PM

Good to see it started

Did you pump the lifters?

Is it that type of Sound at all.

How is the oil pressure?

I had a case where the bolt wasn't tight enough on the crank snout resulting in some strange noises from low oil pressure.

Flitzr951 · 08-10-2007, 03:37 PM

The oil pressure gauge was steady just above 5...but I didn't want to keep the engine running to see if it dropped once everything warmed up. I double checked my crank bolt, it's good at 155ftlbs. Initially, it was idling but it was rough and didn't sound right. I did a compression check (all cylinders were between 170 and 175) after the check I tried starting it again and it still starts right up but it revs up (sounds a lot more normal) and dies. I do have a vacuum leak on my boost pipe but I don't think that's the only thing causing it to die off

***If I remember correctly, my compression when the engine was stock was around 155...is there anything in particular I need to worry about with the higher compression?

nynor · 08-10-2007, 05:02 PM

um.... detonation? melted pistons? probably only under boost, however.

Flitzr951 · 08-10-2007, 06:20 PM

Quote:

Originally Posted by nynor

um.... detonation? melted pistons? probably only under boost, however.

well is 20-25lbs a relatively big difference? I'm guessing I'll just be running less boost. If it is an issue, can't a thicker HG lower it back down to the 155 range?

nynor · 08-11-2007, 05:14 AM

increased compression ratios increased volatility, thus increased likelihood of damage. if you are running less boost, this danger is diminished. you can get thicker head gaskets, but i am not sure how much they would decrease the compression ratio.

Flitzr951 · 08-11-2007, 08:51 AM

Okay, I did another compression check. The first time I did one cylinder at a time (leaving the spark plugs in the other 3 cylinders...with the coil/fuel pump disconnected) This time I pulled all the plugs out first, then checked each cylinder. So the results were a little different: 165 on all cylinders. I don't think the 10psi increase will matter a whole heck of a lot and if it does I'm almost positive a thicker HG will be able to correct it.

bscpanther · 08-11-2007, 09:37 PM

Not to be negative but the compression test was more accurate the first time you did it with the other cylinders plugged. I think you'll be fine, like you've said before, easy on the boost (you shouldn't need much with you're set up) and don't drive (always) like you're running from the cops.