Search found 35 matches

by BenL
Wed Jul 14, 2010 2:53 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

@Phil: I'm using the open style element that I purchased with the kit. I haven't got any datalogs at the moment as the laptop battery is KO'd. Will try and sort some logs out and send them to you sometime soon as I appreciate the offer to take a look. What you say about the poor idle symptoms being ...
by BenL
Tue Jul 13, 2010 9:06 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

I was looking at possibility of enclosing the air filter in a box with a ducted supply from the front of the car. I expect on the move the air taken in is reasonably cool anyway but your suggestion of a heat shield is a good one. @ Eliot: Thanks for the suggestion on setting up MAT correction, will ...
by BenL
Tue Jul 13, 2010 6:26 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

Just a quick post to say thanks so far for all the advice. I've moved the sensor from the plenum and the result has been a major improvement in both the idle and low speed/part throttle running. I think the MAT correction still needs to be set up as I have noticed if pulling up at the lights after a...
by BenL
Wed Jul 07, 2010 10:11 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

I've moved my sensor to the intake now but have the option to move back again. How do you go about setting the air temp correction factors? Maybe you have some example values, would be of much assistance. They definitely need setting as after a run I experimented with pulling the lead off the air te...
by BenL
Thu Jul 01, 2010 9:25 am
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

Interesting thread on the MSExtra forum with a discussion about MAT correction and placement of the IAT sensor.

Worth reading!
by BenL
Thu Jul 01, 2010 8:45 am
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

Cheers I checked some old datalogs last night and the heat soak to IAT is more than evident. You can see it steadily rise up to around 70-80deg and then drop as the car is driven off. What a nugget! Going to make up a new boss today. Look like that NPT tap was a good investment! Looking forward to s...
by BenL
Wed Jun 30, 2010 10:23 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

This is the ATW dyno plot. The 190-200 is a guess at the flywheel power since we didn't do anything to evaluate transmission losses. The car is running standard cast exhaust manifolds and unported late heads. What does that suggest to you in terms of cam spec? It doesn't feel that cammy but it certa...
by BenL
Wed Jun 30, 2010 10:04 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

@TVRleigh: I don't think the 270/110 is that wild a cam looking at the timing and lift figures but I could be wrong. As for the solid and low idle I just love that effortless sound and feel. After driving it a bit over the last couple of days and the recent discussions I have renewed my enthusiasm f...
by BenL
Wed Jun 30, 2010 9:39 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

Well found one problem today. I'd fitted a piece of pipe onto the end of the tank fuel return to direct the flow away from the pickup. Pulled it out today to find it had been to close to the bottom of the tank and so had a kink in it... maybe explains why the pump sounded a bit strained at times! Re...
by BenL
Wed Jun 30, 2010 12:48 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

The air temp sensor in the plenum giving a false reading wasn't something I thought about at the time. I think it usually reads up to about 70deg but it isn't something I have really checked at this stage. Wouldn't be too much trouble to move it though. Where did you site yours? By the way what is i...
by BenL
Tue Jun 29, 2010 7:31 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

@kiwicar: That's what I read last night on some googled info about Fuel Pump cavitation. It's worth a try so I'll try the afformentioned copper tube with formed bends to see. I have to say the car didn't idle well on the weber 500 and distributor(tried every dizzy setup in the book) before. I presum...
by BenL
Tue Jun 29, 2010 6:57 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

It's been changed since that pic was taken and it's now go a piece of copper with two elbows in it.

Going to make a up a piece of 15mm copper tube tonight using a tube bender and run it between the tank outlet and the pump (take out the pre-filter). To see if that has any effect on the pump noise.
by BenL
Tue Jun 29, 2010 1:56 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

@ ChrisJC: The manifold is standard 3.9 EFI but the air filter is a K&N fitted as shown. I made an ally spigot to take the K&N with a nice radius, it uses the original air-hose. I hadn't considered a resonance problem but the idle problem occurs at a variety of speeds. Also the MAP signal is...
by BenL
Mon Jun 28, 2010 10:32 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

BTW That pic shows the original secondhand pump that I had fitted at first.
by BenL
Mon Jun 28, 2010 10:31 pm
Forum: Engines Area
Topic: 3.9 EFI Megasquirt idle and low speed running problems
Replies: 43
Views: 23916

The filter is behind the pump and there is a pic here. Elbow out of tank and U-shaped section of hose between the filter and pump. Could be asking for cavitation problems? I've been here a million times though, I think i've identified the problem make the changes. Start the engine and..... nothing c...

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