Plug and play ecu's

Mk1 gt tubby

Fresh Recruit
Hi all,

I've just bought a mines ecu for my mk1 and wondered about the safety aspect of running 1 bar.
I'm running a FMIC, Decat, HKS actuator, aftermarket manifold and exhaust system. i'm running 10.5 psi at the moment. would i need a rrfpr or can you ecu up the fuel to run a bar safely? I will be uprating the fuel pump as its 30 years old also. I know people seem to go for piggy backs but i prefer PnP for simplicity and lack of trust in tuners. any advice much appreciated.

Thanks in advance
 

dac69er

Super Moderator
it really is a bit of a gamble. it "should" be ok. but even if you dont trust the tuners, i would go somewhere and at least let them do a couple of power runs with a wideband in the exhaust to get an idea of the fuelling.

one thing to note is that the jam p&p ecus (or at least the one i have) actually has a fuel cut at 1.2 bar. so it does have some safety features built in :)
 

Jay

Admin
The majority of these units seem to be set up for use on standard injectors with stock fuel pressure. I've seen them struggle with larger injectors in the past and adjustable regulators will add another variable into things.

The only true way to tell the mixture is with a wideband. Would be a worthwhile addition to any set-up for monitoring purposes and they are quite affordable nowadays. Certainly take a lot of the guesswork out of how safe you are. A local tuner could doublecheck the fueling if you are stuck.
 
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Mk1 gt tubby

Fresh Recruit
Thanks for the replies guy's. So i reckon if i was to run a bar it be worth getting the fueling checked to make sure. What about running 11 psi? surely it should be able to run that safely without wideband or tuner checking the fueling. what do you think? Funds are abit tight at the moment.
 

Jay

Admin
A fuelling check should rule out any worry. Even at low boost levels you could have a duff injector or another lurking issue. When raising boost always err to the side of caution.
 

SWJ

Member
Hmm, we have folks form all world on here (US) here! And as I understand it ... 10.5 psi would be .723 bar and not 1 bar, (14.5 psi.) Can the Jam do that??

AFIK, the Jam ECU and ones like it the first (Plug and Play) for these cars are fairly conservative in nature. They would increase timing slightly and most likely hold the stock injectors open, slightly longer to increase fueling. And that's about it. As long as "mods" stay on the moderate side ... the OP should be fine?? But if the OP starts vary things "wildly" from stock??

Most likely a big turbo and larger exhaust w/o increasing injector capacity, would put him in danger of running lean right quick??And without an increase in timing there is not much point. More timing is the secret to "power" but ... too much timing (On Boost) blows up motors! :)

I don't know what they were doing in Jamaica back in the day?? But they were building 300 hp 4efte's on all stock internals and "not" blowing them up?? And I don't think they were running WB O2's or using stand lone's either??? Hmm maybe E manage Blues??

Don't know but these days there are lot's of stand alones for around 500 us dollars. But most are wire in's at that price. But a few feature "Auto Tune" and take there input from a WB 02 sensor. At any rate a WB o2, and adding one is a good idea in anycase with a turbo motor! As with one, you can see if your running lean under boost ... right quick! Under boot AFR should drop like a stone from 14.7 Stochmetric if it goes up (lean) under boost, back the heck of the throttle right quick! Cuz, even stock ... hoses can pop off!
 

H_D

Member +
I have used a zep, jam and blitz pnp ecu and they all fuelled fine upto 1.2 bar. Blitz seems to run richer than the other 2 and the zep felt the most aggressive.
 

Jay

Admin
Bear in mind too much fuel can be destructive to the engine too. I've seen a JAM ECU overfuel massively on a stock vehicle at idle. Swapped in a SARD unit and it instantly returned to stock limits. That over fuelling would lead to bore wash and potential engine damage.
 

SWJ

Member
I have used a zep, jam and blitz pnp ecu and they all fuelled fine upto 1.2 bar. Blitz seems to run richer than the other 2 and the zep felt the most aggressive.
Most likely if the "Zep" seemed the most aggressive?? Then most likely it made the most power because they pushed the "timing" a little bit further, but still kept it save!
 

SWJ

Member
Bear in mind too much fuel can be destructive to the engine too. I've seen a JAM ECU overfuel massively on a stock vehicle at idle. Swapped in a SARD unit and it instantly returned to stock limits. That over fueling would lead to bore wash and potential engine damage.
I know "nothing" of any of these boxes?? But save to say massive over fueling with stock injectors?? Does not sound right??

"Something" was not right cuz that should not happen?? I would question if the injectors were indeed stock?? The ECU could have failed?? And it was holding the stock injector's wide open ie "100 percent duty cycle?? If they were stock injectors?? Or if they were not they were larger than ... 20 percent?? There is some wiggle run for over sized injectors with stock-ish ECU's .. but it's not much.


At any rate, yep too much fuel will wash down cylinder walls and cause damage in the long run! But on the other hand. more fuel is safe if crap is wrong! You won't have rods going thur the block ... so there is that. On the other hand with a WB O2 sensor one would know, if to much fuel was an issue, right from the start. :)
 

starletsy

Member +
Bear in mind too much fuel can be destructive to the engine too. I've seen a JAM ECU overfuel massively on a stock vehicle at idle. Swapped in a SARD unit and it instantly returned to stock limits. That over fuelling would lead to bore wash and potential engine damage.
Who knows what the Blitz was mapped for though as you know Jay they offered many different turbo kits back in the day from a K1 hybrid, KKK 24 and 26 plus a K03 in the end.
 

SWJ

Member
kkk 24 and 26??? Those are big laggy Turbos on 951's?? Barely civil on a 2.5 Porsche motor! Top end only in my onion. I would think they would have to suck on a 1.5 let alone a 1.3??? If those were an option?? That would have to mean the Blitz Boxers were running a crap load of timing??? Either that or those that chose to run (those Turbo's) ... did not care about anything under ... 4000 rpm??? Sounds like a weird choice?? But unless one has a chip reader ... who knows what those Boxes do???
 

Jay

Admin
Side note - I've a regular K26 on my 5E.

Power delivery is a lot different to the average TD04, it builds a lot of speed without the punch. Really progressive power curve without too much lag at all. Boost level is high to get it into it's zone though (1.6+ bar)

Been in a couple of K24 equipped starlets in the past which offered a similar experience but the 5E really really helps things along.
 

SWJ

Member
Side note - I've a regular K26 on my 5E.

Power delivery is a lot different to the average TD04, it builds a lot of speed without the punch. Really progressive power curve without too much lag at all. Boost level is high to get it into it's zone though (1.6+ bar)

Been in a couple of K24 equipped starlets in the past which offered a similar experience but the 5E really really helps things along.
1.6 bar ... I get 23 psi??? Is that right?? If it is then I have to say .. uh wow! Do you have a build thread cuz I got questions. :)

But quick question how is it "off boost" and at what rpm does the turbo kick in???
 

SWJ

Member
1.6 bar ... I get 23 psi??? Is that right?? If it is then I have to say .. uh wow! Do you have a build thread cuz I got questions. :)

But quick question how is it "off boost" and at what rpm does the turbo kick in???
Oh I see you covered it already thanks.
 
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